Apparently, that "monster black hole" that researchers found isn't so monstrous after all. But finding errors and working to correct them in how science pushes forward.

In a recent study (a peer-reviewed study published Nov. 27), a team of scientists reported the discovery of the binary system LB-1, which contains a star and, according to the findings, a black hole companion 70 times the mass of our sun. This was major news, a stellar-mass black holes (black holes formed by the gravitational collapse of a star) are typically less than half that massive. But while the study, led by Jifeng Liu, of the National Astronomical Observatory of China (NAOC) of the Chinese Academy of Sciences, was exciting, it was also wrong.

Three new papers came out this week that reexamined the findings from Liu's study, and these studies say that LB-1's black hole isn't actually all that massive.

Video: Monster Black Hole 15,000 Light-Years Away? Likely NotRelated:Images: Black Holes of the Universe

Stellar-mass black holes are typically identified by the bright X-ray emissions that come from the gas that the objects accrete, or pull in, from their companion stars. But the black hole spotted in LB-1 is "noninteracting"; in other words, it doesn't accrete gas from its star, so it can't be found through bright emissions. Scientists think that there are many examples of this type of black hole in the universe, but because these objects are tough to spot, there are few observations to show just how many might be out there.

So, to determine that the system had a black hole, Liu's team had to find and study the object indirectly, by observing movement in the Doppler shift of the system's star and a deep-red emission line.

Under the Doppler phenomenon, objects moving toward Earth appear blue, because the light wavelengths are getting shorter, and red when moving away from us, because the wavelengths are getting longer. The emission line, known as an H-alpha emission line, is a spectral line, or a dark line in a spectrum. Spectral lines are often used to identify atoms or molecules and this specific line is created by hydrogen electrons. Liu's team completed their work under the presumption that this line was coming from the accretion disk around the black hole.

Related: Why Are Black Holes So Weird?

By measuring changes in the Doppler shift, researchers could determine the velocity of the objects and, therefore, their mass. "If the star and the companion were accelerating the same amount, that would mean they have the same mass, and if one is accelerating much less, it would be much heavier," University of California, Berkeley, astronomy doctoral student Kareem El-Badry, a co-author on one of the three papers analyzing these results, said. So, in measuring the wiggling movement of the emission coming from (what Liu's team assumed was) the black hole, Liu's team determined that the velocity of the black hole must mean it was extremely massive for a stellar-mass black hole.

Now, if the emission was, in fact, coming from a black hole and moving as they reported, that indeed would mean that there was an extremely massive object in the system, El-Badry explained.

The main problem with this conclusion? It turns out that that this emission line, the motion of which served as the main evidence for the proposed ultramassive object, wasn't wiggling. In fact, it wasn't moving at all, the new papers addressing Liu's team's conclusions found.

The claim of a strangely massive black hole discovery first struck El-Badry as strange, because this type of black hole has never before been observed with such a mass. "My first thought when the paper came out is this is such a bold claim that the evidence better be really good," El-Badry told Space.com. "You should always keep an open mind, but in this case, the claim was definitely extraordinary and the evidence was a bit more shaky."

The main issue that El-Badry found was that the emission line only appeared to be moving; it wasn't actually wiggling.

El-Badry and Eliot Quataert, a professor of astronomy and physics at UC Berkeley, published their analysis on Monday (Dec. 9) to the preprint server arXiv. Their paper has also been submitted for publication in the journal the Monthly Notices of the Royal Astronomical Society.

Related: The Strangest Black Holes in the Universe

So, how can an emission line only "appear to be moving"? Well, it just so happened to line up on top of an absorption line, which created the illusion.

To understand the illusion, you first need to know what an absorption line is. The outer atmospheric layers surrounding stars serve as an absorbing material to absorb light coming from the star. So, when researchers study the spectrum of light coming from stars, they can see absorption lines, which are created by atoms in the atmosphere transitioning between atomic states.

With the star in LB-1, there was an absorption line "hidden" by the emission line, El-Badry said. Such a situation can create the illusion that the emission line is moving, producing the appearance of Doppler shift, which El-Badry and the scientists behind the other papers explained and showed in the studies. By simply subtracting the absorption line from measurements of the emission line, El-Badry and Quataert, who used the same data for their study as Liu's team did, found that the emission line wasn't moving at all.

Without the movement of this emission, Todd Thompson, a professor in the Department of Astronomy at The Ohio State University, who wasn't involved in any of these papers, explained to Space.com, there are two possible interpretations. Either the second object in the system is far more massive than has ever been observed (way more than 70 solar masses) or, much more likely, there could just an average-size black hole in LB-1 and the emission line is coming from somewhere else, Thompson said.

"There's something there. It's just that it's probably just a regular, stellar-mass black hole," Jackie Faherty, a senior scientist at the American Museum of Natural History in New York and a co-host of "StarTalk Radio," told Space.com. Faherty wasn't involved in any of these papers.

However, because the emission line is probably not coming from the black hole, researchers can't get a super precise estimate of the black hole's mass. But the analysis of El-Badry's team suggests that the black hole is most likely between 5 and 20 solar masses, which, as they described in their paper, "seems most plausible."

Related: No Escape: Dive Into a Black Hole (Infographic)

Two additional papers have come out that also reexamine the claims made by Liu's team. One, a study led by New Zealand theoretical astronomer J.J. Eldridge, which has been published to arXiv, took a theoretical approach to analyzing the system. Researchers in that study simulated a large library of different kinds of binary systems to see if the scientists could find a binary that matched the observations reported for LB-1. They found several that could, but none with 70-solar-mass black holes.

The other study, also published to arXiv, and led by Michael Abdul-Masih of the Institute of Astronomy at the university KU Leuven in Belgium, took a similar approach to El-Badry's. However, instead of using the same data as Liu's team, these researchers collected their own spectrum of the binary system using a different telescope. They also did simulations in which they put an absorption line beneath an emission line to see if the emission appeared to move as the one in LB-1 did. In these simulations, Abdul-Masih's team found that the line did appear to move back and forth, providing further evidence that the emission line in the system only looks like it's moving.

"It did seem a little too exciting to be true," Faherty said. But, she added, "this is also the way science progresses."

Faherty emphasized that "This is OK for this kind of thing to happen. It's just a correction to a previous result it's OK to have this kind of situation," she added. "Science advances and moves forward."

These follow-up studies have provided evidence that the secondary object in LB-1 is not actually an ultrarare, ultramassive black hole. However, it is still an exceptionally interesting object and worth studying further, El-Badry said.

Because there has been so much attention on the original study, including with these follow-up analyses, it has increased interest in the study of the LB-1 system and systems like it.

By identifying and studying noninteracting black holes like the one associated with LB-1, scientists can learn more about these elusive objects. Said to be common in space, they are tough to spot, because they don't produce bright X-ray emissions.

"It's a very interesting time to go looking for these noninteracting black holes, and they definitely have found a very interesting system," Thompson said. There is a "population that must be out there of black holes in stellar binaries where there's no active interaction between the two components," he added.

Additionally, it could be interesting if scientists continue to investigate where exactly this H-alpha emission line is coming from. The papers reexamining LB-1 suggest "that it's possible that circumbinary material could account for it, but it's a slight mystery it's OK to have some mystery involved in a result," Faherty said.

Space.com reached out to Liu's team for comment, and Liu said that "We are writing a paper to address all these concerns." He added that his team expects that paper to be out sometime next week.

Follow Chelsea Gohd on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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'Monster Black Hole' Discovery Found to be Incorrect But That's How Science Progresses - Space.com

This article by David Weintraub is republished here with permission from The Conversation. This content is shared here because the topic may interest Snopes readers; it does not, however, represent the work of Snopes fact-checkers or editors.

Bright stars top Christmas trees in Christian homes around much of the world. The faithful sing about the Star of Wonder that guided the wise men to a manger in the little town of Bethlehem, where Jesus was born. Theyre commemorating the Star of Bethlehem described by the Evangelist Matthew in the New Testament. Is the stars biblical description a pious fiction, or does it contain some astronomical truth?

To understand the Star of Bethlehem, we need to think like the three wise men. Motivated by this star in the east, they first traveled to Jerusalem and told King Herod the prophecy that a new ruler of the people of Israel would be born. We also need to think like King Herod, who asked the wise men when the star had appeared, because he and his court, apparently, were unaware of any such star in the sky.

These events present us with our first astronomy puzzle of the first Christmas: How could King Herods own advisors have been unaware of a star so bright and obvious that it could have led the wise men to Jerusalem?

Next, in order to reach Bethlehem, the wise men had to travel directly south from Jerusalem; somehow that star in the east went before them, til it came and stood over where the young child was. Now we have our second first-Christmas astronomy puzzle: how can a star in the east guide our wise men to the south? The north star guides lost hikers to the north, so shouldnt a star in the east have led the wise men to the east?

And we have yet a third first-Christmas astronomy puzzle: how does Matthews star move before them, like the taillights on the snowplow you might follow during a blizzard, and then stop and stand over the manger in Bethlehem, inside of which supposedly lies the infant Jesus?

The astronomer in me knows that no star can do these things, nor can a comet, or Jupiter, or a supernova, or a conjunction of planets or any other actual bright object in the nighttime sky. One can claim that Matthews words describe a miracle, something beyond the laws of physics. But Matthew chose his words carefully and wrote star in the east twice, which suggests that these words hold a specific importance for his readers.

Can we find any other explanation, consistent with Matthews words, that doesnt require that the laws of physics be violated and that has something to do with astronomy? The answer, amazingly, is yes.

Astronomer Michael Molnar points out that in the east is a literal translation of the Greek phrase en te anatole, which was a technical term used in Greek mathematical astrology 2,000 years ago. It described, very specifically, a planet that would rise above the eastern horizon just before the sun would appear. Then, just moments after the planet rises, it disappears in the bright glare of the sun in the morning sky. Except for a brief moment, no one can see this star in the east.

We need a little bit of astronomy background here. In a human lifetime, virtually all the stars remain fixed in their places; the stars rise and set every night, but they do not move relative to each other. The stars in the Big Dipper appear year after year always in the same place. But the planets, the sun and the moon wander through the fixed stars; in fact, the word planet comes from the Greek word for wandering star. Though the planets, sun and moon move along approximately the same path through the background stars, they travel at different speeds, so they often lap each other. When the sun catches up with a planet, we cant see the planet, but when the sun passes far enough beyond it, the planet reappears.

And now we need a little bit of astrology background. When the planet reappears again for the first time and rises in the morning sky just moments before the sun, for the first time in many months after having been hidden in the suns glare for those many months, that moment is known to astrologers as a heliacal rising. A heliacal rising, that special first reappearance of a planet, is what en te anatole referred to in ancient Greek astrology. In particular, the reappearance of a planet like Jupiter was thought by Greek astrologers to be symbolically significant for anyone born on that day.

Thus, the star in the east refers to an astronomical event with supposed astrological significance in the context of ancient Greek astrology.

What about the star parked directly above the first crche? The word usually translated as stood over comes from the Greek word epano, which also had an important meaning in ancient astrology. It refers to a particular moment when a planet stops moving and changes apparent direction from westward to eastward motion. This occurs when the Earth, which orbits the sun more quickly than Mars or Jupiter or Saturn, catches up with, or laps, the other planet.

Together, a rare combination of astrological events (the right planet rising before the sun; the sun being in the right constellation of the zodiac; plus a number of other combinations of planetary positions considered important by astrologers) would have suggested to ancient Greek astrologers a regal horoscope and a royal birth.

Molnar believes that the wise men were, in fact, very wise and mathematically adept astrologers. They also knew about the Old Testament prophecy that a new king would be born of the family of David. Most likely, they had been watching the heavens for years, waiting for alignments that would foretell the birth of this king. When they identified a powerful set of astrological portents, they decided the time was right to set out to find the prophesied leader.

If Matthews wise men actually undertook a journey to search for a newborn king, the bright star didnt guide them; it only told them when to set out. And they wouldnt have found an infant swaddled in a manger. After all, the baby was already eight months old by the time they decoded the astrological message they believed predicted the birth of a future king. The portent began on April 17 of 6 BC (with the heliacal rising of Jupiter that morning, followed, at noon, by its lunar occultation in the constellation Aries) and lasted until December 19 of 6 BC (when Jupiter stopped moving to the west, stood still briefly, and began moving to the east, as compared with the fixed background stars). By the earliest time the men could have arrived in Bethlehem, the baby Jesus would likely have been at least a toddler.

Matthew wrote to convince his readers that Jesus was the prophesied Messiah. Given the astrological clues embedded in his gospel, he must have believed the story of the Star of Bethlehem would be convincing evidence for many in his audience.

David Weintraub, Professor of Astronomy, Vanderbilt University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Can Astronomy Explain the Biblical Star of Bethlehem? - Snopes.com

Our entire cosmic history is theoretically well-understood, but only because we understand the... [+] theory of gravitation that underlies it, and because we know the Universe's present expansion rate and energy composition. Light will always continue to propagate through this expanding Universe, and we will continue to receive that light arbitrarily far into the future, but it will be limited in time as far as what reaches us. We still have unanswered questions about our cosmic origins, but the age of the Universe is known.

Conceptually, it might seem like the simplest idea in existence to determine the age of the Universe.Once you figure out that the Universe is expanding, all you need to do is measure the expansion rate today and use the laws of physics to determine how the expansion rate must have changed over time. Instead of extrapolating forward to determine the fate of the Universe, you do the calculating backwards instead, and go all the way back until you achieve the conditions of the hot Big Bang itself.

This obvious method not only works, but it remains the best way we have to calculate the Universe's age even today. Yet it's very easy to go awry, as there are many simplifying assumptions you can make that will give you an easy answer that isn't necessarily correct, including errors that even a Nobel Laureate made earlier this year. Here's how you, too, can figure out the age of the Universe.

Standard candles (L) and standard rulers (R) are two different techniques astronomers use to measure... [+] the expansion of space at various times/distances in the past. Based on how quantities like luminosity or angular size change with distance, we can infer the expansion history of the Universe. Using the candle method is part of the distance ladder, yielding 73 km/s/Mpc. Using the ruler is part of the early signal method, yielding 67 km/s/Mpc.

The first place to start is with the expanding Universe itself and the one parameter we've strived to measure longer than any other: the Hubble constant. On the largest scales, the galaxies we find in the Universe obey a very simple relation between the two observable quantities of distance and redshift, where the farther away an object is from us, the greater its measured redshift will be.

Remarkably, the law that relates them is extremely straightforward: the recession speed that you would infer from a galaxy's redshift equals the distance to that galaxy multiplied by the Hubble constant. Even more remarkably, that constant has the same value for pretty much every galaxy we measure, particularly for galaxies within a few billion light-years of us. Even though there are additional cosmic motions inherent to each galaxy induced by gravitational effects, this law remains true when you average over all the galaxies you can find.

The redshift-distance relationship for distant galaxies. The points that don't fall exactly on the... [+] line owe the slight mismatch to the differences in peculiar velocities, which offer only slight deviations from the overall observed expansion. The original data from Edwin Hubble, first used to show the Universe was expanding, all fit in the small red box at the lower-left.

So what do we measure the Hubble constant to be? It depends on how you measure it, since:

Why these two values don't match and why they give such different, mutually inconsistent answers is one of the major conundrums of modern cosmology.

A series of different groups seeking to measure the expansion rate of the Universe, along with their... [+] color-coded results. Note how there's a large discrepancy between early-time (top two) and late-time (other) results, with the error bars being much larger on each of the late-time options. The only value to come under fire is the CCHP one, which was reanalyzed and found to have a value closer to 72 km/s/Mpc than 69.8.

However, the very astute among you will notice something about the Hubble constant itself: it comes in units that are a speed (km/s) per unit distance (Mpc, where 1 megaparsec is about 3.26 million light-years). If you look at a galaxy that's 100 Mpc away, you'd expect it to recede away ten times faster than one only 10 Mpc away, but only one-tenth as fast as a galaxy 1,000 Mpc away. That's the simple power of the redshift-distance relation.

But there's another way to manipulate the Hubble constant: to recognize that a speed (distance-per-time) per (divided by) unit distance (distance) is the same as units of inverse time. What could the physical meaning of that "inverse time" correspond to? Perhaps, you might reasonably imagine, it could correspond to the age of the Universe.

The different possible fates of the Universe, with our actual, accelerating fate shown at the right.... [+] The specifics of the Universe's composition affect the age of the Universe, as you can see by looking at the 'start point' occurring at different values in the past for different cosmologies, even with the exact same expansion rate today.

There are approximately 3.1 1019 kilometers in one megaparsec, which means that if you turn the Hubble constant into an inverse time, you find some fascinating things.

These are both almost equal to the accepted age of the Universe, but not quite. In addition, they're both almost equal to one another, but differ by approximately the same amount that the two estimates for the Hubble constant differ by: 9% or so.

However, you cannot simply change the age of the Universe by changing the Hubble constant, and there's a subtle but vital reason why this is so.

A photo of me at the American Astronomical Society's hyperwall in 2017, along with the first... [+] Friedmann equation at right. The first Friedmann equation details the Hubble expansion rate squared on the left hand side, which governs the evolution of spacetime. The right side includes all the different forms of matter and energy, along with spatial curvature (in the final term), which determines how the Universe evolves in the future. This has been called the most important equation in all of cosmology, and was derived by Friedmann in essentially its modern form back in 1922.

The value of the Hubble constant today isn't simply the inverse of the value of the age of the Universe, even though the units work out to give you a measure of time. Instead, the expansion rate that you measure the Hubble constant today must balance the sum total of every form of energy that contributes to the Universe's composition, including:

The equation that governs the expanding Universe (shown above) can be solved exactly in some simple cases.

The scale of the Universe, on the y-axis, is plotted as a function of time, on the x-axis. Whether... [+] the Universe is made of matter (red), radiation (blue), or energy inherent to space itself (yellow), it decreases towards a size/scale of 0 as you extrapolate backwards in time. The age of the Universe multiplied by the Hubble constant will equal different values for Universes made up of different compositions.

If your Universe is exclusively made up of radiation, you find that the Hubble constant multiplied by the age of the Universe since the Big Bang equals , exactly. If your Universe is exclusively made up of matter (normal and/or dark), you find that the Hubble constant multipled by the age of the Universe equals, exactly. And if your Universe is entirely made of dark energy, you'll find that there is no exact answer; the value of the Hubble constant multiplied by the age of the Universe always continues to increase (towards infinity) as time goes on.

This means that if we want to accurately calculate the age of the Universe, we can do it, but the Hubble constant alone isn't enough. In addition, we also need to know what the Universe is made out of. Two imagined Universes with the same expansion rate today but made out of different forms of energy will have different expansion histories and, therefore, different ages from one another.

Measuring back in time and distance (to the left of "today") can inform how the Universe will evolve... [+] and accelerate/decelerate far into the future. We can learn that acceleration turned on about 7.8 billion years ago with the current data, but also learn that the models of the Universe without dark energy have either Hubble constants that are too low or ages that are too young to match with observations. If dark energy evolves with time, either strengthening or weakening, we will have to revise our present picture. This relationship enables us to determine what's in the Universe by measuring its expansion history.

So, to find out how old the Universe actually is since the onset of the hot Big Bang, all we have to do is determine the expansion rate of the Universe and what the Universe is made out of. There are a variety of methods that we can use to make this determination, but there's one vital thing we have to remember: many of the ways we have of measuring one parameter (like the expansion rate) are dependent on our assumptions about what the Universe is made out of.

In other words, we cannot assume that the Universe is made out of a certain amount of matter, a certain amount of radiation, and a certain amount of dark energy in a way that's independent of the expansion rate itself. Perhaps the most powerful way to illustrate this is to look at the leftover glow from the Big Bang itself: the Cosmic Microwave Background.

The leftover glow from the Big Bang, the CMB, isn't uniform, but has tiny imperfections and... [+] temperature fluctuations on the scale of a few hundred microkelvin. While this plays a big role at late times, after gravitational growth, it's important to remember that the early Universe, and the large-scale Universe today, is only non-uniform at a level that's less than 0.01%. Planck has detected and measured these fluctuations to better precision than ever before, and can use the fluctuation patterns that arise to place constraints on the Universe's expansion rate and composition.

This, above, is a map of the fluctuations in the Cosmic Microwave Background. Overall, every direction in the Universe displays the same average temperature as every other direction: approximately 2.725 K. When you subtract that mean value out, you get the pattern that you see above: the fluctuations, or departures from the average temperature.

Where you see dark blue or dark red spots, those are regions where the temperature fluctuations are largest: approximately 200 microkelvin colder (for blue) or hotter (for red) than the mean value. These fluctuations exhibit particular patterns in their magnitude on a variety of angular scales, with the fluctuations rising in magnitude down to some particular angular scale of about 1 degree, then decreasing and increasing in an oscillatory fashion. Those oscillations tell us some vital statistics about the Universe.

Four different cosmologies lead to the same fluctuation patterns in the CMB, but an independent... [+] cross-check can accurately measure one of these parameters independently, breaking the degeneracy. By measuring a single parameter independently (like H_0), we can better constrain what the Universe we live in has for its fundamental compositional properties. However, even with some significant wiggle-room remaining, the age of the Universe isn't in doubt.

What's most important to realize is that there are many possible combinations of values that can fit any particular graph. For example, given the fluctuations we see, we can have a Universe with:

You will notice a pattern here: you can have a larger Hubble constant if you have less matter and more dark energy, or a smaller Hubble constant if you have more matter and less dark energy. What's remarkable about these combinations, however, is that they all lead to almost exactly the same age for the Universe since the Big Bang.

There are many possible ways to fit the data that tells us what the Universe is made of and how... [+] quickly it's expanding, but these combinations all have one thing in common: they all lead to a Universe that's the same age, as a faster-expanding Universe must have more dark energy and less matter, while a slower-expanding Universe requires less dark energy and greater amounts of matter.

The reason that we can claim the Universe is 13.8 billion years old to such enormous precision is driven by the full suite of data that we have. A Universe that expands more quickly needs to have less matter and more dark energy, and its Hubble constant multiplied by the age of the Universe will have a larger value. A slower-expanding Universe requires more matter and less dark energy, and its Hubble constant multiplied by the age of the Universe gets a smaller value.

However, in order to be consistent with what we observe, the Universe can be no younger than 13.6 billion years and no older than 14.0 billion years, to more than 95% confidence. There are many properties of the Universe that are indeed in doubt, but its age isn't one of them. Just make sure you take the Universe's composition into account, or you'll wind up with a naive and incorrect answer.

The rest is here:

This Is How Astronomers Know The Age Of The Universe (And You Can, Too) - Forbes

Our Milky Way Galaxy consists of two disk-like structures, known as thick and thin disks. The thick disk contains only about 20% of the Galaxys total stars, and, based on its vertical puffiness and composition, is thought to be the older of the pair. Using data from NASAs Kepler space telescope, astronomers have calculated that the thick disk is about 10 billion years old.

From a great distance, our Milky Way Galaxy would look like a thin disk of stars that orbits once every few hundred million years around its central region, where hundreds of billions of stars provide the gravitational glue to hold it all together. But this pull of gravity is much weaker in the Galaxys far outer disk. There, the hydrogen atoms making up most of the Milky Ways gas disk are no longer confined to a thin plane, instead they give the disk an S-like, or warped, appearance. Image credit: Xiaodian Chen.

This finding clears up a mystery, said lead author Dr. Sanjib Sharma, an astronomer at the ARC Centre of Excellence for All Sky Astrophysics in Three Dimensions (ASTRO-3D) and the University of Sydney.

Earlier data about the age distribution of stars in the disk didnt agree with the models constructed to describe it, but no one knew where the error lay in the data or the models. Now were pretty sure weve found it.

Dr. Sharma and colleagues used a method known as asteroseismology, a way of identifying the internal structures of stars by measuring their oscillations from star quakes.

The quakes generate soundwaves inside the stars that make them ring, or vibrate, explained Dr. Dennis Stello, from ASTRO-3D and the University of New South Wales.

The frequencies produced tell us things about the stars internal properties, including their age. Its a bit like identifying a violin as a Stradivarius by listening to the sound it makes.

An artists impression of the Milky Way Galaxy, showing the thick and thin disks. Image credit: NASA / JPL Caltech / R.Hurt / SSC.

This age-dating allows the researchers to essentially look back in time and discern the period in the Universes history when the Milky Way formed a practice known as galactic archaeology.

Not that they actually hear the sound generated by star-quakes. Instead, they look for how the internal movement is reflected in changes to brightness.

Stars are just spherical instruments full of gas, but their vibrations are tiny, so we have to look very carefully, Dr. Sharma said.

The exquisite brightness measurements made by Kepler were ideal for that. The telescope was so sensitive it would have been able to detect the dimming of a car headlight as a flea walked across it.

The data delivered by Kepler during the four years after it was launched in 2009 presented a problem for astronomers.

The information suggested there were more younger stars in the thick disk than models predicted.

The question confronting scientists was stark: were the models wrong, or was the data incomplete?

A fresh spectroscopic analysis revealed that the chemical composition incorporated in the existing models for stars in the thick disk was wrong, which affected the prediction of their ages.

Taking this into account, the researchers found that the observed asteroseismic data now fell into excellent agreement with model predictions.

The results provide a strong indirect verification of the analytical power of asteroseismology to estimate ages, Dr. Stello said.

The results are published in the Monthly Notices of the Royal Astronomical Society.

_____

Sanjib Sharma et al. 2019. The K2-HERMES Survey: age and metallicity of the thick disc. MNRAS 490 (4): 5335-5352; doi: 10.1093/mnras/stz2861

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Milky Way's Thick Disk is 10 Billion Years Old, Astronomers Say | Astronomy - Sci-News.com

Australian astronomy punches well above its weight, in terms of the research it leads and the facilities it houses.

We have made remarkable discoveries in the past year alone. Our scientists have recently narrowed down the time frame for the first light in the universe. We have established that the black hole in the Milky Way had a massive explosion just 3.5 million years ago.

Our facilities from the Murchison Widefield Array in Western Australia to the Anglo-Australian Telescope in New South Wales are important parts of the worlds astronomical ecosystem.

But to make the most of the next wave of stargazing technology, we will need true diversity in our astronomical community.

As I argue in a paper published this week in Nature Astronomy, Australias astronomers have made great strides in improving diversity in recent years and the way we have achieved this offers lessons for other scientific communities.

Read more: Science prizes are still a boys' club. Here's how we can change that

Very soon, however, even more impressive stargazing hardware is due to start operating. The Australian segment of the Square Kilometre Array, and the Extremely Large Telescope in Chile will be part of a new generation of mega-telescopes.

These new super-tools will be capable of revealing the universe in unprecedented detail, and gathering data in unprecedented bulk. As a discipline, we must be prepared to extract maximum benefit from them.

Sifting maximum signal from this fresh collection of noise will not simply require more astronomical hands on deck. It will require different types of hands, and different ways of seeing.

There is ample evidence from other fields particularly business to show the benefits of diversity within organisations, at all levels. It results in higher productivity, more profits, and more robust outcomes.

And its not just in social work or education. Even in number-crunching science, personal history and lived experience influence decisions, how questions are framed, and how networks are built.

In recent years, Australian astronomy has made striking progress towards gender equity, in large part because of a system known as the Pleiades Awards operated by the Astronomical Society of Australia.

There are about 500 working astronomers in this country. The 2016-25 Australian Astronomy Decadal Plan, commissioned by the Australian Academy of Science, sets a target of 33% of positions at all levels to be filled by women within the next six years.

The Pleiades provide a structured approach to improving equity. Given the enthusiastic participation of almost all the 14 universities, two Centres of Excellence and three organisations that house Australias astronomical communities, I have little doubt that this marker will be achieved.

However, we need to broaden our thinking, and our ideas of what constitutes a fair and empathetic workplace, beyond simple questions of binary gender.

Read more: Why I joined #500queerscientists

The next generation of telescopes will be huge international collaborations with intense competition between partner countries. To extract the maximum benefit from the extraordinary power of these telescopes, we need to look beyond traditionally conservative hiring practices.

We will need to draw on people from every possible background and experience, and inject new ideas. We need to draw from the academic talent and insight to be found among LGBTIQA+ astronomers, Indigenous astronomers, disabled astronomers, chronically ill astronomers, and astronomers who hail from non-Western cultures.

There are skilled and highly gifted scientists who fall within these categories, yet for some the prospect of a stable long-term career with steady support and funding seems faint. Science research organisations and institutions are as guilty as those in any other field of not building proper structures around understanding, inclusion and empathy.

As female astronomers not too many years ago would often testify, sometimes the welcome and support inside the Australian faculties and organisations could have been a bit warmer.

Thanks to the schemes such as the Pleiades, women in my field can reasonably expect to be recognised for their skills, and to be promoted according to their merits.The same cannot yet be said for people in other, more heterogeneous categories, and that must now start to change. Fairness demands it, but just as importantly the science requires it.

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Science needs true diversity to succeed -- and Australian astronomy shows how we can get it - The Conversation AU

Artist impression of what MAMBO-9 would look like in visible light. The galaxy is very dusty and it has yet to build most of its stars. Credit: NRAO/AUI/NSF, B. Saxton

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have spotted the light of a massive galaxy seen only 970 million years after the Big Bang. This galaxy, called MAMBO-9, is the most distant dusty star-forming galaxy that has ever been observed without the help of a gravitational lens.

We were in doubt if it was real, because we couldnt find it with other telescopes. But if it was real, it had to be very far away. Manuel Aravena

Dusty star-forming galaxies are the most intense stellar nurseries in the universe. They form stars at a rate up to a few thousand times the mass of the Sun per year (the star-forming rate of our Milky Way is just three solar masses per year) and they contain massive amounts of gas and dust. Such monster galaxies are not expected to have formed early in the history of the universe, but astronomers have already discovered several of them as seen when the cosmos was less than a billion years old. One of them is galaxy SPT0311-58, which ALMA observed in 2018.

Because of their extreme behavior, astronomers think that these dusty galaxies play an important role in the evolution of the universe. But finding them is easier said than done. These galaxies tend to hide in plain sight, said Caitlin Casey of the University of Texas at Austin and lead author of a study published in The Astrophysical Journal. We know they are out there, but they are not easy to find because their starlight is hidden in clouds of dust.

ALMA radio image of the dusty star-forming galaxy called MAMBO-9. The galaxy consists of two parts, and it is in the process of merging. Credit: ALMA (ESO/NAOJ/NRAO), C.M. Casey et al.; NRAO/AUI/NSF, B. Saxton

MAMBO-9s light was already detected ten years ago by co-author Manuel Aravena, using the Max-Planck Millimeter BOlometer (MAMBO) instrument on the IRAM 30-meter telescope in Spain and the Plateau de Bure Interferometer in France. But these observations were not sensitive enough to reveal the distance of the galaxy. We were in doubt if it was real, because we couldnt find it with other telescopes. But if it was real, it had to be very far away, says Aravena, who was at that time a Ph.D. student in Germany and is currently working for the Universidad Diego Portales in Chile.

Thanks to ALMAs sensitivity, Casey and her team have now been able to determine the distance of MAMBO-9. We found the galaxy in a new ALMA survey specifically designed to identify dusty star-forming galaxies in the early universe, said Casey. And what is special about this observation, is that this is the most distant dusty galaxy we have ever seen in an unobstructed way.

The light of distant galaxies is often obstructed by other galaxies closer to us. These galaxies in front work as a gravitational lens: they bend the light from the more distant galaxy. This lensing effect makes it easier for telescopes to spot distant objects (this is how ALMA could see galaxy SPT0311-58). But it also distorts the image of the object, making it harder to make out the details.

In this study, the astronomers saw MAMBO-9 directly, without a lens, and this allowed them to measure its mass. The total mass of gas and dust in the galaxy is enormous: ten times more than all the stars in the Milky Way. This means that it has yet to build most of its stars, Casey explained. The galaxy consists of two parts, and it is in the process of merging.

Casey hopes to find more distant dusty galaxies in the ALMA survey, which will give insight into how common they are, how these massive galaxies formed so early in the universe, and why they are so dusty. Dust is normally a by-product of dying stars, she said. We expect one hundred times more stars than dust. But MAMBO-9 has not produced that many stars yet and we want to find out how dust can form so fast after the Big Bang.

Observations with new and more capable technology can produce unexpected findings like MAMBO-9, said Joe Pesce, National Science Foundation Program Officer for NRAO and ALMA. While it is challenging to explain such a massive galaxy so early in the history of the universe, discoveries like this allow astronomers to develop an improved understanding of, and ask ever more questions about, the universe.

The light from MAMBO-9 traveled about 13 billion years to reach ALMAs antennas (the universe is approximately 13.8 billion years old today). That means that we can see what the galaxy looked like in the past (Watch the video above to learn how ALMA works as a time-machine). Today, the galaxy would probably be even bigger, containing one hundred times more stars than the Milky Way, residing in a massive galaxy cluster.

Reference: Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85 by Caitlin M. Casey, Jorge A. Zavala, Manuel Aravena, Matthieu Bthermin, Karina I. Caputi, Jaclyn B. Champagne, David L. Clements, Elisabete da Cunha, Patrick Drew, Steven L. Finkelstein, Christopher C. Hayward, Jeyhan S. Kartaltepe, Kirsten Knudsen, Anton M. Koekemoer, Georgios E. Magdis, Allison Man, Sinclaire M. Manning, Nick Z. Scoville, Kartik Sheth, Justin Spilker, Johannes Staguhn, Margherita Talia, Yoshiaki Taniguchi, Sune Toft, Ezequiel Treister and Min Yun, 11 December 2019, The Astrophysical Journal.DOI: 10.3847/1538-4357/ab52ff

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

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Astronomers Discover MAMBO-9, Most Distant Dusty Star-Forming Galaxy We Were in Doubt if It Was Real - SciTechDaily

Using the Atacama Large Millimeter/submillimeter Array (ALMA), an international team of astronomers has spotted an unlensed, dusty star-forming galaxy system in the early Universe. Dubbed MAMBO-9 (also known as MM J100026.36+021527.9), the system is composed of a pair of galaxies separated by approximately 20,000 light-years. The light from MAMBO-9 traveled about 13 billion years to reach Earth.

An artists impression of what the dusty star-forming galaxy MAMBO-9 would look like in visible light. Image credit: NRAO / AUI / NSF / B. Saxton.

Dusty star-forming galaxies are the most intense stellar nurseries in the Universe. They contain huge amounts of gas and dust and form stars at a rate up to a few thousand solar masses per year.

Such monster galaxies are not expected to have formed early in the history of the Universe, but astronomers have already discovered several of them as seen when the cosmos was less than a billion years old.

Because of their extreme behavior, astronomers think that these dusty galaxies play an important role in the evolution of the Universe.

These galaxies tend to hide in plain sight. We know they are out there, but they are not easy to find because their starlight is hidden in clouds of dust, said Dr. Caitlin Casey, an astronomer at the University of Texas at Austin.

MAMBO-9 was first detected 10 years ago by the Max-Planck Millimeter BOlometer (MAMBO) instrument on the IRAM 30-m telescope in Spain and the Plateau de Bure Interferometer in France. But those observations were not sensitive enough to reveal the distance.

We were in doubt if it was real, because we couldnt find it with other telescopes. But if it was real, it had to be very far away, said Dr. Manuel Aravena, a researcher at the Universidad Diego Portales in Chile.

ALMA radio image of MAMBO-9. Image credit: ALMA / ESO / NAOJ / NRAO / Casey et al / AUI / NSF / B. Saxton.

Thanks to ALMAs sensitivity, the team has now been able to determine the distance of MAMBO-9.

We found the galaxy in a new ALMA survey specifically designed to identify dusty star-forming galaxies in the early Universe. And what is special about this observation, is that this is the most distant dusty galaxy we have ever seen in an unobstructed way, Dr. Casey said.

The scientists saw MAMBO-9 directly, without a gravitational lens, and this allowed them to measure its mass.

The total mass of gas and dust in the galaxy is enormous: 10 times more than all the stars in the Milky Way. This means that it has yet to build most of its stars, Dr. Casey said.

The astronomers hope to find more distant dusty galaxies in the ALMA survey, which will give insight into how common they are, how these massive galaxies formed so early in the Universe, and why they are so dusty.

The discovery of MAMBO-9 is described in a paper in the Astrophysical Journal.

_____

Caitlin M. Casey et al. 2019. Physical Characterization of an Unlensed, Dusty Star-forming Galaxy at z = 5.85. ApJ 887, 55; doi: 10.3847/1538-4357/ab52ff

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Merging Pair of Dusty Star-Forming Galaxies Spotted 13 Billion Light-Years Away | Astronomy - Sci-News.com

Life from Space

Scientists want to understand how life arose on Earth. To do that, they must first unravel how organic molecules form and interact in environments without living things. Geologic activity has erased records of much of the chemistry that happened pre-life on Earth. But meteorites -- pieces of primitive solar system rocks that have fallen to Earth -- preserve chemical records of what the solar system was like in our planet's early days.

We rely on meteorites to tell this story, said Daniel Glavin, an astrobiologist at NASAs Goddard Space Flight Center and an author of the new study. Theyre basically frozen time capsules.

Scientists studying meteorites have already found molecules like amino acids and nucleobases, which are necessary for life. But they'd never seen ribose. This sugar makes up the backbone of RNA, a type of molecule responsible for carrying genetic messages in our cells. Furukawas team employed careful techniques to ensure they wouldnt destroy the sugars in their attempts to find them, and were able to uncover ribose and other sugars.

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Astronomers look inside meteorites and find the sugars needed for life - Astronomy Magazine

For the modern astronomer, satellites are just a part of life. There are more than 2,000 active ones currently orbiting Earth, and the smartest minds in space photography have managed to work out clever ways of removing the occasional fly over from their images of space.

But then there's Starlink. The first stages of SpaceX's plan to launch up to 42,000 satellites to provide Earth with complete internet coverage have clocked in at 122 objects so far; after the first major launch in May, astronomers were worried.

Now a second launch has occurred, and their concerns have truly started to materialise.

In the early hours of the morning on November 18 at the Cerro Tololo Inter-American Observatory (CTIO) in Northern Chile, the trail of newly launched Starlink satellites flew overhead, absolutely filling an image taken by the Dark Energy Camera (DECam).

Each one of those dotted line trails in the image below is a Starlink satellite.

(Cliff Johnson/Clara Martnez-Vzquez/DELVE Survey)

While taking about 40 exposures of the Small and Large Magellanic Clouds, SpaceX's Starlink satellite train entered the camera's vision around 90 minutes before sunrise, shining bright in the early morning sunlight and taking a whole five minutes to pass out of the telescope's view.

"Wow!! I am in shock," wrote CTIO astronomer Clara Martinez-Vazquez on Twitter.She noted there were 19 satellite trails, which is way more than a normal satellite pass.

Although most of the time the satellites will be dark in the night sky (which still presents some problems), just after the Sun goes down, or early morning when the sky is still black, sunlight can still hit the satellites, making them visible both by fancy astronomy telescopes, and just regular old binoculars.

"These things are big enough that when they're sunlit, they're bright enough to pick up with anything from binoculars and bigger," Cees Bassa from the Netherlands Institute for Radio Astronomy told Forbes.

And astronomers are not impressed. As we've reported before, they've brought up some big issues with Starlink.Firstly, there are going to be a lot of these objects in orbit, which could dramatically impact the way astronomers can see and listen to the sky.

"A full constellation of Starlink satellites will likely mean the end of Earth-based microwave-radio telescopes able to scan the heavens for faint radio objects," Swinburne University astronomer Alan Duffy told ScienceAlert in May after the first launch of Starlink satellites.

The second batch of 60 Starlink satellites was launched just over a week ago on November 11, so they haven't yet reached their final operational altitude - but that altitude is expected to be lower than for the first batch.

Sky watchers are also finding that Starlink are more reflective then other satellites. If thousands of extra satellites weren't already a problem on their own, the fact they are extra-shiny is just another thing astronomers are pulling their hair out about.

Astronomers can remove the trails from their images when Starlink swans into view, but much of the information scientists use is contained in the raw images, not the pretty photos we see. Additionally, it's one thing to remove a single satellite trail from an image, and another to remove 19.

So far, some people are coping by poking fun at SpaceX's Elon Musk on social media.

How astronomers and SpaceX will resolve these conflicting needs is still unknown, but with two more launches scheduled this year, there's a chance this won't be the last we'll hear about this problem.

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That Starlink Problem Astronomers Were Worried About Is Totally Happening - ScienceAlert

The LSST is being built on Cerro Pachn in Chile.

Will Elon Musk's SpaceX Starlink project end ground-based astronomy as we know it? Despite only 122 of a planned total of 42,000 broadband internet satellites being in orbit so far, astronomers are now gravely concerned about the mega-constellations effect on the US$466 million Large Synoptic Survey Telescope (LSST), one of the worlds most new important telescopes currently being built on the Cerro Pachn ridge in Chiles Elqui Valley.

From 2022, the LSST will survey the entire visible sky in just three nights, effectively producing a motion picture of our Universe. For anything that changes in the sky, the LSST will be the finderscope, says Aaron Roodman, an experimental cosmologist at Stanford University involved in instrument construction and preparations for the LSST. Were going to find a hundred thousand supernova by the time the project is over.

Crucially, the LSST will also catalog 90 percent of near-Earth objects larger than 300m and calculate if they are a threat to Earth.

Starlink is a threat to all that, and according to one astronomer involved in the LSST, SpaceX needs to do something about the visibility of its satellites.

The 6.5 meter mirror awaits installation at the LSST.

Cerro Pachn is the next mountain peak along from the Cerro TololoInter-American Observatory (CTIO)s main site in Chile, which a series of 19 Starlink satellites passed over on Nov. 18, 2019 and ruined observations from its Blanco telescope.

A 6.5 meter-class optical telescope designed to survey the visible sky every week at a far fainter level than presently possible, the LSST will have a 3.2-gigapixelCCD imagingcamera, the largest digital camera ever constructed.

The chamber inside the LSST that will eventually host humanity's biggest-ever camera.

If a supernova goes off, or an asteroid is spotted thats on a dangers trajectory, the LSST will find them, and in real-time alert astronomers and tell them where to point their larger telescopes.

A successor to the Subaru TelescopeandPan-STARRS, the LSST will be the latest and greatest sky survey. It will be uniquely sensitive to changes, something known as time domain astronomy. The LSST will snap 1,000 photographs each night in six wavelengths, from ultraviolet to near infrared, totalling 15 terabytes. Using a custom-made fiberoptic network installed on Cero Pachn, that data will be uploaded in real-time for use by astronomers around the world. Within a minute of taking an image, any object whose brightness or position has changed compared to previous images, will get flagged, says Roodman. In real time the images will be sent via fast fiber to the supercomputer centre at the National Center for Supercomputing Applications (NCSA) at the University of Illinois for primary processing.

The LSST is being built next to the Gemini South Observatory on Cerro Pachn in Chile on a sight ... [+] where astronomers witnessed a two-minute total solar eclipse on July 2, 2019.

The LSSTs decade-long survey of the night sky is due to begin in 2022 and catalog 40 billion celestial objects by 2032. It will also locate 10,000 primitive objects in the Kuiper Belt and study dark energy and dark matter. In the long term its data ought to allow astronomers to generate a highly detailed map of billions of galaxies, stars and objects in the solar system.

LSST uniquely scans the sky with a fast and wide cadence going to very faint limits, says Dr. Tony Tyson, Distinguished Professor at UC Davis, California and Chief Scientist for the LSST. This means that of all observatories it is most impacted by tens of thousands of bright low earth orbit satellites."

The fear is that its long exposure images of the night sky will contain streaks of lightStarlink satellitesthat block precisely what the LSST is trying to see.

Knowing the exact trajectory of the 42,000 Starlink satellites would help astronomers better aim the LSST away from the streaks, but only some of the time. There will be so many it is not feasible to dodge them, says Tyson. The only hope is for the operators like SpaceX to make them dimmer.

The exterior of the now-being-built LSST on Cerro Pachn.

Its even more of an issue for asteroid-detection because that takes place best at dusk and dawn which is precisely when satellites catch the glare of the Sun and become easily visible.

So why does it need such a big camera? We want to get images of every part of the sky as quickly as possible and maximise the field of viewhow big each picture is, says Roodman. The LSSTs field of view will be three and a half degrees across, which is about seven times the diameter of the full moon. To have such a big field of view you need a big camera and a big focal point, says Roodman. The camera will contain 189 custom-made 16 megapixel super-flat CCD sensors so advanced that it will be possible to digitize the entire image in only two seconds. We need to minimize the amount of time that we're not looking at the heavens, says Roodman. Its also a fast system with an aperture of f1.2 so we can get a picture with a narrow region in focus similar to bokeh.

On the way up to the LSST on Cerro Pachn.

Financially supported by the National Science Foundation (NSF), the Department of Energy Office of Science and private funding, the LSSTs construction is being supervised by the Association of Universities for Research in Astronomy (AURA), an international consortium of universities and non-profit institutions that operate world-class astronomy facilities. In Chile, it already administers and operates the telescopes of Cerro Tololo, Gemini South, SOAR, and in the future LSST.

Wishing you clear skies and wide eyes

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Will SpaceXs Starlink Mega-Constellation Ruin Astronomys Biggest Ever Eye On The Sky? - Forbes

The arrangement of the two moons orbits is an example of what scientists call an orbital resonance. Repeating patterns in their orbits apply a regular set of gravitational forces to the two moons. In this case, the repeating forces keep the moons in their orbits, but resonances can be disruptive as well.

Astronomers have found many examples of orbital resonances in the solar system. Pluto and Neptune are in a resonance in which Pluto orbits the Sun twice for every three times that Neptune does. This resonance keeps the two objects orbits stable. Within the asteroid belt, there are gaps without asteroids where resonance patterns from Jupiters orbit disrupt the path of large groups of space rocks.

However, the newly discovered resonance of Naiad and Thalassa isnt like anything scientists have seen in the solar system so far. Naiad and Thalassa are two small moons, each about 60 miles or so in size, with orbits nestled close together. Thalassa circles Neptune in about 7.5 hours, while Naiad laps it from the inside, taking just 7 hours per orbit.

But Naiads orbit is tilted by almost 5 degrees relative to Thalassas orbit and Neptunes equator. This makes the little moon weave up and down in a wave motion that keeps it farther from Thalassa even as it passes by. Though it looks bizarre, the arrangement reinforces the moons orbits and keeps them stable despite being so near each other.

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A weird, orbital dance keeps these moons of Neptune safely on track - Astronomy Magazine

Astronomers at Cardiff University have done something nobody else has been able to do. A team, led by Dr. Phil Cigan from Cardiff Universitys School of Physics and Astronomy, has found the neutron star remnant from the famous supernova SN 1987A. Their evidence ends a 30 year search for the object.

SN 1987A was a supernova in the Large Magellanic Cloud. It was a Type II supernova about 168,000 light years away, and the light reached Earth in 1987. Its scientifically significant because it presented a great opportunity to study core-collapse supernovae through its different phases.

For the very first time we can tell that there is a neutron star inside this cloud within the supernova remnant.

But even though scientists learned a lot by observing it, one question remained unanswered, until now. Where was the neutron star that should lie at the center of the expanding shock-wave? Supernova theory says it should be there, and neutrino data from the time provided the evidence.

Since nobody could find it, different reasons were advanced for why it wasnt there. Some wondered if SN 1987A formed a quark star instead of a neutron star. Another theory suggested that a pulsar was formed instead, and that its magnetic field was small or unusual, preventing us from detecting it. A third possibility was that gas and dust fell back into the neutron star, collapsing it into a black hole.

A more prosaic explanation was that it was there, just obscured by so much gas and dust that we cant see it.

Now this team says theyve found it with the Atacama Large Millimeter/sub-millimeter Array (ALMA) telescope. Its hiding in a particularly bright patch of dust, right where the neutron star should be. The prosaic explanation wins again.

The team published their findings in the Astrophysical Journal. The paper is titled High Angular Resolution ALMA Images of Dust and Molecules in the SN 1987A Ejecta. The lead author is Dr. Phil Cigan from Cardiff University.

For the very first time we can tell that there is a neutron star inside this cloud within the supernova remnant, Dr. Cigan said in a press release. Its light has been veiled by a very thick cloud of dust, blocking the direct light from the neutron star at many wavelengths like fog masking a spotlight.

Dr. Mikako Matsuura is a senior lecturer in the School of Physics and Astronomy at Cardiff University. Her research focuses on dust and molecules in supernova and supernova remnants, and she was one of the authors of this study.

Our new findings will now enable astronomers to better understand how massive stars end their lives

Although the light from the neutron star is absorbed by the dust cloud that surrounds it, this in turn makes the cloud shine in sub-millimetre light, which we can now see with the extremely sensitive ALMA telescope, said Matsuura.

Our new findings will now enable astronomers to better understand how massive stars end their lives, leaving behind these extremely dense neutron stars, continued Dr. Matsuura.

The light from SN 1987A was first spotted on February 23rd, 1987. It was about 160 million light years away, but it flared with light equal to 100 million Suns, and was bright for several months.

SN 1987A was the closest supernova in 400 years. Not since Keplers Supernova in 1604 has there been one this bright and this close. (Keplers Supernova was in the Milky Way, only 20,000 light years away.) Its been a constant object of attention to astronomers and astrophysicists, and theyve watched it closely for over three decades now.

The supernova explosion created a massive expanding shock-wave of gas, super-heated to over a million degrees F. As the gas cooled, some of it turned solid, forming a dense cloud of dust. Inside that dust is the neutron star, right where scientists thought it would be.

We are confident that this neutron star exists behind the cloud and that we know its precise location, said Matsuura. Perhaps when the dust cloud begins to clear up in the future, astronomers will be able to directly see the neutron star for the very first time.

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Astronomers Finally Find the Neutron Star Leftover from Supernova 1987A - Universe Today

Astronomers have investigated the nature of a very bright and long-duration gamma-ray burst, GRB 190114C, by studying its environment.

Hubbles observations suggest that GRB 190114C displayed powerful emission because the collapsing star was sitting in a very dense environment, right in the middle of a bright galaxy 5 billion light years away. Image credit: NASA / ESA / Hubble / M. Kornmesser.

Gamma-ray bursts are the most energetic explosions in the Universe, beaming out mighty jets which travel through space at 0.99 times the speed of light, as a star much more massive than our Sun collapses at the end of its life to produce a black hole.

GRB 190114C was detected by a suite of telescopes, including NASAs Swift and Fermi telescopes, as well as by the Major Atmospheric Gamma Imaging Cherenkov telescopes, on January 14, 2019.

Some of the light detected from the object had the highest energy ever observed: 1 TeV (Tera electron volt) about one trillion times as much energy per photon as visible light.

Follow-up observations were made with the NASA/ESA Hubble Space Telescope to study the environment around GRB 190114C and find out how this extreme emission is produced.

Hubbles observations suggest that this particular burst was sitting in a very dense environment, right in the middle of a bright galaxy 5 billion light years away. This is really unusual, and suggests that might be why it produced this exceptionally powerful light, said Dr. Andrew Levan a researcher at Radboud University.

GRB 190114C: the left panel shows a close pair of interacting galaxies, which is a host system of GRB 190114C; the location of GRB 190114C is indicated with a red circle; the right panel shows the optical counterpart of GRB 190114C. Image credit: de Ugarte Postigo et al, arXiv: 1911.07876.

The astronomers used Hubble, together with ESOs Very Large Telescope and the Atacama Large Milimeter/submilimeter Array (ALMA), to study the host galaxy of GRB 190114C.

They investigated whether the environmental properties of the host system, which is composed of a close pair of interacting galaxies, might have contributed to the production of these very-high-energy photons.

GRB 190114C occurred within the nuclear region of a massive galaxy, a location that is rather unique.

This is indicative of a denser environment than that in which gamma-ray bursts are typically observed and could have been crucial for the generation of the very-high-energy photons that were observed.

Scientists have been trying to observe very-high-energy emission from gamma-ray bursts for a long time, said Dr. Antonio de Ugarte Postigo, a scientist in the Instituto de Astrofsica de Andaluca.

This new observation is a vital step forward in our understanding of gamma-ray bursts, their immediate surroundings, and just how matter behaves when it is moving at 99.999% of the speed of light.

A paper outlining the Hubble observations appears in the journal Nature.

An additional paper that details an analysis of the galaxy hosting GRB 190114C will be published in the journal Astronomy & Astrophysics.

_____

V.A. Acciari et al. 2019. Observation of inverse Compton emission from a long -ray burst. Nature 575: 459-463; doi: 10.1038/s41586-019-1754-6

A. de Ugarte Postigo et al. 2019. GRB 190114C in the nuclear region of an interacting galaxy A detailed host analysis using ALMA, HST and VLT. A&A, in press; arXiv: 1911.07876

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Astronomers Observe Host Galaxy of Extremely Bright and Long Gamma-Ray Burst | Astronomy - Sci-News.com

David, a NASA engineer, has dreamed about working in aerospace since the third grade. What his coworkers dont know: Hes been passionate about astrology for almost as long, and is a practicing astrologer.

For an hourly rate, David offers readings on the weekends to clients. Hes considering writing a book about his method of reading natal charts. But he keeps this passion tightly under wraps because hes afraid stigma against astrology in the scientific community and among lovers of astronomy, the study of celestial objects and phenomena, can cause problems at work. (David is not his real namehe agreed to this interview on the condition of anonymity.)

Im basically in the closet. It sounds terrible but I dont know how else to phrase it, he said.

In reality both astrology and astronomy date back at least thousands of years, with logs of observations by astrologers playing a key role in modern meteorology and other studies. Until the last several hundred years, many astronomers includingfamously, Johannes Kepler openly studied or practiced astrology and believed celestial bodies had an impact on people.

But from a steady parade of think pieces debating the merits of astrology, to an entire segment of Bill Nye Saves the World devoted to challenging the practice, astrology is a favorite target today for many space lovers. Astrologers believe the hate is based on a misunderstanding of what astrology is. Astrologers love astronomy but many astronomers hate astrology, said Annabel Gat, senior astrologer at VICE, adding that she could empathize with the frustration people feel when astrology and astronomy are confused.

A common misunderstanding by skeptics, for example, is that interpretations are based on the physical location of those constellations today. But if you look into a telescope, youll find they are not where theyre supposed to be, David said. Constellations are not equally spaced...Every 72 years, [they] drift by one degree, and every sign is 30 degrees, so after a certain amount of time you can be off by a whole sign.

When an astrologer calls something that is open to interpretation a science, then asserts that the sun is in Virgo right now when its really in Leo, then astronomers are not going to be very happy, he said. Non-astrologers often think the position of these constellations today prove that astrology isnt real.

Modern western astrology bases interpretations on the location of planets, the sun, and the moonalso called planets in astrology vocabularyfrom the perspective of a persons location on Earth. When reading natal charts or doing forecasting (readings of the cosmic weather of the day), astrologers use zodiacal archetypes, which are indeed linked to 12 constellations, but only symbolicallytheir locations do not matter.

Those who use the tropical zodiac base their interpretations on fixed zodiacal seasons that correspond with the seasonal movement of the sun. At one point, the constellations did align with the signs. That was meant to be a temporary guide. Whats really valuable is how the season progresses, how the sun travels through the season...not where the actual stars are, David said. Nature is driven mainly by the season...and we are linked to the natural cycles of nature.

This disconnect between how astrology is practiced and how astrology skeptics think it is practiced, is enough for David to practice astrology in secret. That wasnt always the casehe harbored passion for both science and astrology since age 11, when his parents first brought home a copy of Kepler, a computer program by Cosmic Patterns Software Inc. that generates and interprets natal charts. In high school, he began studying astrology and doing readings for his classmates.

When David went to college to study aerospace engineering, he didnt immediately tell his classmates he was into astrology since he wasnt sure how it would be received. But a writing class that was part of his honors program led to a paper on the correlation between space shuttle disasters and astrology, and his cover was blown. Everyone was impressed [by my presentation], and it helped that the teacher was a strong believer in astrology, he said.

David is careful again at work, howevernot because he thinks his coworkers would take issue with his interest in astrology, but because he worries about people outside of NASA causing trouble. NASA itself has published some literature, including this Tumblr post in 2016 about constellations and the beginnings of Babylonian astrologya post that seems to incorrectly position astrology as being related to current locations of constellations, but which astrology skeptics nevertheless seized on to pen pieces titled, Astrology is bullsh*t. NASA's scathing takedown perfectly explains why.

Astrology is not in our purview, but astronomy and space science is, a NASA spokeswoman said. The Tumblr post merely pointed out the history and math of how the 12 constellations used in astrology came to be. As for employees studying or practicing astrology, she said, What employees choose to pursue personally on their free time is up to them, and we have no concerns or comment.

David doesnt think the Tumblr post is representative of everyone at NASA. People who work at NASA are human..theyre open-minded, he said. But on the outside, people are ruthless with attacks on the Internet, and its those attacks he fears the most. Just like people attack astrologers online, they would attack a government agency like NASA probably ten times harder, he said.

On the list of ruthless critics? The science guy himself, Bill Nye, who debated with astrologer Samuel Reynolds on his Netflix show, Bill Nye Saves the World, in 2017, arguing that astrology is a pseudoscience. Reynolds response was that, in order for something to be a pseudoscience, its practitioners would first have to believe it is a science.

David said he feels the same way. Whereas an attribute of science is repeatability, astrology is an art...its subject to interpretation, he said. My reading will be different than another astrologers reading. He also uses astrology as a tool for self improvementnot as a predictor of the future. My specialty is using astrology to get to know yourself...It gives you clues for how to exploit your strengths and overcome your weaknesses.

Likening astrology to science makes it easier for skeptics to write astrology off, David said. On the scientific level, none of the known scientific forces apply to astrology, he said. Electromagnetic forces are too weak. The gravitational force between you and the person next to you is stronger than the gravitational force Pluto has on you, because its so far away.

Still, some aspects of aerospace design are also based on statistics, not science, David said. A lot of things in aerospace are based on empirical approaches, just as my belief in astrology is. In that sense, theyre both non-scientific. One may plot a bunch of data points on what other planes have looked like, to predict what would happen if the size or weight of a wing is changed.

In astrology, what Ive seen is significant beyond mere coincidence, by far, he said, noting what fans of astrology know well, which is that a persons chart involves not just their sun signthe most common way astrology is discussed in pop culturebut also their moon sign, and all the planets, asteroids, and more.

Even as astrology is enjoying as much popularity as ever, reactions to astrologers can be mixed. Ashley Otero, an astrologer who writes lunar horoscopes for VICEs Astro Guide app and also practices acupuncture, said people have fallen silent or seemed surprised when astrology came up in conversation as an acupuncturist. Once, she was told by a colleague that they didnt want to be associated with that part of her life.

Alice Bolen, an osteopath and astrologer who writes advanced horoscopes for Astro Guide, said negative perceptions of astrology are something every astrologer has to get over at some point. Because it takes so much time and energy to learn astrology, it will always be easy for skeptics to remain skeptical, she said, adding that she disagreed with the idea that things need to be this OR that, like both spiritual and scientific, or intuitive and logical. Arent we dynamic, fluid beings at this point capable of multi-modal analysis?

Meanwhile, Priya Kale, who writes Astro Guides rising horoscopes, likens staying in the proverbial closet to invalidating something David believes in. There comes the bigger question in every individuals lifedo I live in alignment with what I have experienced to be true, or in fear of what society will think? Kale said she was questioned by her family when she said she would be a full-time astrologer.

David disagreed. What I believe in, or what I dont believe in, doesnt need to be validated for the world, he said, adding that he believes he can have more of an impact in the scientific world if he avoids giving ammunition to people who want to attack or discredit his work.

The double life David lives is weighing on his decision of whether or not to publish a book on astrology. In fact, his day job at NASA is also secretive. It works both ways. Most of the things I do at work are non-sensitive, but there are a few things that I have to keep more on the downlow, he said.

Im still not sure how to come out and still be safe..I want to do it, but I have this invisible hand pulling me back, David said. For now, as a naturally private person and Geminithe sign represented by twins and known for dual personalitieshe doesnt mind. Geminis are good at keeping secrets, when they want to.

Download the Astro Guide app by VICE on an iOS device to read daily horoscopes personalized for your sun, moon, and rising signs, and learn how to apply cosmic events to self care, your friendships, and relationships.

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Meet the NASA Engineer Who Secretly Practices Astrology - Free

Venus and Jupiter were the opening act.

At twilight, the two planets, visible to the naked eye, appeared to nearly bump into each other before setting in the western sky.

That 'conjunction' kicked off the last star party of 2019 for the Tulare Astronomical Association. Between 50 and 70 people turned out toArthur Pursell Observatory to gaze up at the heavens and see Saturn's rings, the Andromeda Galaxy, double stars, different types of star clusters and various planetary nebulas.

The International Space Station even made a quick appearance, shooting across the sky at 5 miles per second.

Tulare Astronomical Association member Butch Demmers gives a presentation during the star party at the Arthur Pursell Observatory on Saturday, Nov. 23.(Photo: Kyra Haas)

Before most of the viewing got underway, TAA member and former club president Butch Demmers presentedinside the club's meeting roomto give attendees a better sense of what they would see.

"That way, they would have a little bit more knowledge of when they're looking at something, what that something is instead of just a patch of light up in the sky," Demmers said.

Outside the dome, which holds the club's 12.5 inchCave Astrola Telescope, club members set up other telescopes on pads to show gazers different parts of the night sky.

Club members Don and Sally Belflowerof Bakersfieldnot only showed viewers the stars, but also how to operate the telescope, twisting knobs to center the star in a projected bullseye, then adjusting the focus to view the object clearly.

Sally said Don became interested in astronomy when their daughter was 8 or 9, thinking it was a way to "expand her horizons." Ten years later, Don and Sally are active members of both Tulare's and Bakersfield's astronomy clubs. Their daughter occasionally participates, but not as much.

"She's 18," Sally said with a laugh. "She does OK, but it's not her thing."

Star party attendees line up to look in the telescope at the Arthur Pursell Observatory on Saturday, Nov. 23.(Photo: Kyra Haas)

MichaelTeller, 12, was at the star party with his mother, Marianna, and three of his four siblings. They came to surprise his father, Joseph, an English professor and TAA member with a passion for astronomy.

"Our youngest is 4 now, and it's to the point where we can actually all make it," Marianna said.

Michael said his fascination with astronomy started around age 9 when his father started taking him to TAA events. He said the coolest thing he's ever seen is a meteor.

"It was right over there, and there were orange flames shooting behind it for like three seconds," he said.

Saturday was the last star party of the calendar year becausecloudy, rainy and cold weather in December and January aren'tideal for viewing,Demmers said.

Many of the telescopes, he said, have corrector plates thatare subject to getting "dewed up" when the air has high humidity,which also makes winter observation a challenge.

"Once it gets fogged up, you can't un-fog it," he said.

Demmers said they'll start hosting star parties again around February.

TAA started in 1967 and has about 30 active members. The group's next discussion is at 7:30 p.m. onDec. 4, at the observatory.

The Tulare Astronomical Association sign hangs adjacent to the observing dome at Arthur Pursell Observatory.(Photo: Kyra Haas)

Stars light up the night sky during a star party outside Arthur Pursell Observatory on Saturday, Nov. 23.(Photo: Kyra Haas)

Reach reporter Kyra Haasby emailat khaas@visaliatimesdelta.com or find her onTwitter@kc_haas.

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Stargazers turn out in droves for last 'star party' of 2019 - Visalia Times-Delta and Tulare Advance-Register

The Alpha Monocerotids happened as predicted, even if not quite as we expected.

Michael Boyle Sr. caught an Alpha Monocerotid speeding through Orion last night. I saw 20 meteors in an hour (not 400) from a dark sky site. But they were faint," writes Boyle. Michael Boyle Sr.

Astronomy is just so weird. Sometimes you have to take it in stride. After the hype of the Alpha Monocerotids of which I'm partly to blame the shower proved to be very weak. Michael Boyle Sr., an amateur astronomer in Florida, an ideal spot from which to view the event, reported about 20 meteors per hour at peak. Others saw a few. I stood in a bitter cold wind for an hour and 15 minutes and saw exactly one.

I can't tell you exactly why the shower was a dud, but it's safe to say our understanding of the Alpha Monocerotids is imperfect despite the fact that the researchers nailed the predicted peak within 10 minutes of the original estimate (5:00 UT vs. 4:50 UT). While the 400 meteors per hour rate was for ideal conditions over a short period of time, the radiant was low for many observers in the U.S., so fewer meteors were expected. Still, I was surprised that I saw almost none. My skies were excellent despite occasional clouds, with the winter Milky Way easily visible. The radiant stood a couple of fists above the horizon. (Nov. 23 update: The count was off by a factor of 5 possibly due to Earth grazing the comet's trail instead of passing directly through it.)

While waiting and watching for meteors, other sights made the outing a special one including seeing Sirius reflecting on Lake Superior. Bob King

While astronomers can predict the positions of planets and stars like clockwork, some phenomena remain elusive. The aurorae are a prime example infamous for either not showing up on time, not happening when they're "supposed to," or appearing unexpectedly.

Native American mythology makes room for nature's unpredictable side by including a character called the trickster, which usually takes the form of an animal. Locally, he's a coyote. The trickster is a supernatural being who likes to mess with humans and break the rules. If you're a skywatcher, it eventually becomes second-nature to allow for a potentially spectacular event to not happen at all. Yes, there is disappointment, but there is often joy in the occasion for the simple reason that you showed up.

Showing up means you invested a part of yourself and time to pay attention to something in that big world out there. In doing so, you've also opened yourself up to experiencing something unexpected. At the very minimum, those who did go out last night got to see Orion and Sirius in all their twinkling glory. I saw that . . . and a little more.

The sky over my house was solidly overcast an hour before the start of shower, but for some reason was clear over the neighboring Lake Superior. I wished for a boat. In lieu of that, I got in the car and drove the two miles down to the lake. Incredibly, a chunk of clear sky hung open in the southeastern sky in the direction of Orion and the shower. Elsewhere clouds hung thickly.

Spectacular shower, right? Nope. What you're seeing is actually a train of F-16 jets flying in a formation over Lake Superior. The bright star is Sirius. Bob King

I set up a camera, stood in the 20 mph, 20 wind, and watched. I saw a couple of sporadic or unrelated meteors but no shower members until around 10:37 p.m. That's when I noticed what looked like sparks flashing from the radiant (from where the meteors appear to stream), southwest of Procyon, a star near the constellation of Monoceros, the Unicorn.

The sparking continued for several minutes and looked almost exactly like distant fireworks pop! pop pop! pop! I started yelling crazy "wows" into the wind, thinking this was it, the event we had all hoped for until I looked around and noticed there weren't any sister meteors plowing across the rest of the sky. That wasn't normal. A couple minutes later the flashes had shifted further west and eventually it became apparent: I was looking at a bunch of airplanes!

We have a national guard air base in Duluth, Minnesota, and the pilots will routinely practice flying at night over Lake Superior and the neighboring state of Wisconsin. I'd never seen so many bunched up so close at a distance. Their flashing lights mimicked head-on meteor flares and created the perfect fake meteor shower with a "radiant" or direction of travel from the southeast of Monoceros.

By 11 o'clock the Big Dipper began to climb the northeastern sky once again.Bob King

The sole Alpha Monocerotid I saw streaked slowly upward from the Unicorn and sliced across Orion, maxing out around first magnitude. For me, though, the Milky Way was enough, the Big Dipper standing on his handle above wispy clouds, and the roar of waves slapping the rocks below the road where I parked my car.

Now nearly frozen, I collapsed the tripod and got back into the car at 11:30 p.m., strangely content after not seeing what might have been the best meteor shower of my life.

This post originally appeared in AstroBob: Celestial happenings you can see from your own backyard.

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Meteor Shower Was a Dud, But Showing Up Was Half the Fun - Sky & Telescope

Gazing up at Ithacas clear night skies, one may wonder what exactly is up there just beyond the stratosphere. For anyone curious to learn about the workings of the universe, the stars and the planet, Ithaca Colleges new astronomy club is here to educate members.

Senior Mia Manzer, Astronomy Club president and co-founder, said the clubs leaders want to share their passion and engage students at the college with astronomy.

Manzer said the club will be holding biweekly meetings and will host different events, like movie nights, theme nights and star parties, which are outdoor observation nights. During the star parties, students will have the opportunity to use portable telescopes, look at constellations and learn about the universe beyond their lenses.

The club was created in Fall 2019 and is currently awaiting official recognition by the college, Manzer said.

Freshman Antara Sen, Astronomy Club secretary, said she is hoping to utilize the colleges Clinton B. Ford Observatory, a building on campus that is not currently in use, to hold open events for students and the greater Ithaca community. Sen said the club is going to host fundraisers to raise money to repair the observatory, but it does not have a set fundraising goal yet.

We have a really good observatory that does not get as much usage as it could, said Matthew Price, Astronomy Club adviser and associate professor in the Department of Physics and Astronomy.

Price said the club will be reaching out to students, alumni and faculty for donations to go toward repairing the observatory.

The club itself supports the Ford telescope, he said. It supports outreach. It helps the students to help to do these things. Its about taking the next step and getting everyone active.

Junior club member George Cozma said the club is looking to involve students in the refurbishing process for the observatory. He said the club may open up the observatory during repairs and have students come in to paint the panels of the observatory dome.

We want to generate interest in the beginning, Sen said. We also want to keep that interest alive for the rest of the year.

Cozma said that he is most excited to get the club fully recognized and to begin having regular meetings and hosting events and that planning club activities has been difficult. He said one of the greatest issues the club has is planning around unpredictable weather. The telescopes cannot be used in the rain or snow, so the outdoor star party events are subject to cancellation.

The clubs first star party was scheduled for Oct. 1 on the quad in front of Roy H. Park Hall but was canceled due to impending rain, Manzer said. The club is still working on rescheduling the first event, she said.

The telescopes, which are provided by the college, function better in colder temperatures, so the club will continue hosting outdoor events throughout the academic year and during the winter months as long as the weather permits, Sen said.

Manzer said her goal for the club is to promote engagement in astronomy from students outside of the colleges Department of Physics and Astronomy. Club meetings will be open to all students, and Manzer encourages anyone to attend regardless of their major or experience with astronomy.

We want people to feel involved and be interested in learning about space and our universe and just have fun with it, she said.

Sen said she believes all students could benefit from learning about astronomy. She said the club officials will help to teach and answer any questions inexperienced members may have.

Thats why were building the Astronomy Club, Sen said. In our club meetings, we want to educate our members about the night sky and about the constellations and planets that we will be able to see.

Price said the club is looking to engage the campus and act as an outlet for students who are interested in the topic and looking for help understanding the basics.

The club can be campuswide, he said. It can recruit across the campus and help people be involved. The telescope can be used by any human who has an interest. They just need a little training.

Sen said she believes the club offers useful information about astronomy and space exploration that students may not learn in their classes. She said that the club will make the topic more easily understood and will initiate discussions about current issues in the world.

We have so many crises on earth right now, like the energy crisis, she said. There are so many things wrong right now, and I think that space exploration gives at least a new avenue for research, a new avenue for looking into something that not a lot of people have ventured into.

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Astronomy Club plans events to engage with the community - The Ithacan

Professional and amateur astronomers from the NASA-funded Backyard Worlds: Planet 9 project have spotted a co-moving pair of low-mass brown dwarfs in the solar neighborhood.

An artists rendering of two brown dwarfs. Image credit: Roberto Molar Candanosa & Sergio Dieterich, Carnegie Institution for Science.

To shine bright, stars need the energy derived from the fusion of hydrogen atoms deep in their interiors. If too small, hydrogen fusion cant occur, so the object cools, darkens, and turns into something called a brown dwarf.

On the high mass end, brown dwarfs overlap in observable properties with the coolest stars like TRAPPIST-1 which hosts seven terrestrial worlds, said Dr. Jacqueline Faherty, an astronomer at the American Museum of Natural History, and colleagues.

On the low mass end, they overlap with the observable properties of directly imaged exoplanets like 51 Eri b and Beta Pictoris b.

One of the most important and outstanding questions in substellar mass science is how these objects form and evolve, they said.

Co-moving companions are a key sub-population for investigating questions of formation.

The newfound pair of brown dwarfs is older than 500 million years and younger than 10 billion years.

Designated WISE 2150-7520AB (W2150AB for short), it lies approximately 79 light-years away.

The system consists of two brown dwarfs of spectral types L1 and T8.

The primary member of the system, W2150A, has an estimated mass of 72 times that of Jupiter. The secondary member, W2150B, is 34 times heavier than Jupiter.

The distance between the two objects is around 341 AU (1 AU is the distance from the Sun to Earth).

This image shows the brown dwarf binary system WISE 2150-7520AB. Image credit: Faherty et al, arXiv: 1911.04600.

W2150AB was first spotted in data from NASAs Wide-Field Infrared Survey Explorer (WISE) via the Backyard Worlds: Planet 9 project.

The BackyardWorlds: Planet 9 project has been operational since February 2017, Dr. Faherty and co-authors explained.

The scientific goal of the project is to complete the census of the solar neighborhood (including the Solar System, e.g. Planet 9) with objects that are detectable primarily at mid infrared wavelengths and that were missed by previous searches.

Three citizen science users (Sam Goodman, Dan Caselden, and Guillaume Colin) brought to our attention a WISE W2 only detected source with significant motion, the astronomers said.

They used the Google form and emphasized the objects importance by emailing the Backyard Worlds distribution list as well as key researchers on our team. In addition, these users easily noted a bright source that appeared to be co-moving.

The scientists then confirmed the discovery using the 6.5-m Baade Magellan telescope and the Folded-port InfraRed Echellette (FIRE) spectrograph.

W2150AB resembles 2MASS J11011926-7732383AB (2M1101AB), the first brown dwarf binary discovered with a separation of over 20 AU, they said.

2M1101AB, discovered in the Chamaeleon star-forming region, was heralded as a source of definitive insight into the formation of brown dwarfs. But W2150AB leaves us with an intriguing question about whether it is an evolved version of 2M1101AB or perhaps a system that formed in a low density cluster that survived unperturbed by interactions with nearby stellar or giant molecular cloud.

Given that it is easily resolved with ground or space based observatories, W2150AB is an excellent benchmark system for understanding how brown dwarfs form and evolve together, the researchers concluded.

Their paper will be published in the Astrophysical Journal.

_____

Jacqueline K. Faherty et al. 2019. WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9. ApJ, in press; arXiv: 1911.04600

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Two Co-Moving Brown Dwarfs Spotted 79 Light-Years Away | Astronomy - Sci-News.com

PUNE: Scientists at the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research (NCRA-TIFR, Pune) and the Indian Institute of Science Education and Research, Mohali (IISER- Mohali) have used the upgraded Giant Metrewave Radio Telescope (GMRT) to carry out the most distant measurement of the atomic hydrogen content of galaxies in the early Universe, informed NCRA.

The GMRT is built and operated by NCRA-TIFR and is among the largest radio telescopes in the world. Galaxies like the Milky-way are made up of stars and gas. The life cycle of a galaxy is essentially the conversion of gas to stars through gravitational collapse of gas clouds.

Understanding how galaxies form and evolve thus requires measurements of how both their stars and gas evolve with time. Over the last two decades, astronomers have accurately measured the stellar masses and star formation rates of populations of galaxies at different epochs in the Universe. However, little is known about the evolution of the atomic gas content of galaxies, the fuel for star formation.

Scientists at the NCRA-TIFR and IISER-Mohali have used the upgraded GMRT to measure gas contents in most distant galaxies. Apurba Bera, a Ph.D. student at NCRA-TIFR and the lead author of the paper, said, Most of the atomic gas in galaxies is in the form of hydrogen, which emits a characteristic spectral line at the radio wavelength of 21.11 cm. Unfortunately, this hydrogen emission is weak, and even powerful radio telescopes like GMRT do not have sufficient sensitivity to detect the emission from very distant galaxies. However, the wide frequency coverage of the upgraded GMRT allowed to add the hydrogen emission signals from a large number of galaxies in the field of view of the telescope, so as to measure their average gas content..

The study resulted in a measurement of the average atomic gas content of star-forming galaxies located 4 billion light years away, when the Universe was about two-thirds of its current age. Remarkably, the authors found that both the star-formation efficiency of galaxies and the cosmological gas mass density in galaxies appear to have not changed significantly over the last 4 billion years.

Jayaram Chengalur, a professor at NCRA-TIFR and a co-author of the paper, said The measurement critically requires simultaneous observations of a large number of galaxies. This was possible due to the recent upgrade of the GMRT, as its large bandwidth and superb digital systems allowed us to cover more than 400 galaxies simultaneously. Jasjeet Singh Bagla, a professor at IISER-Mohali and also a co-author, mentioned that his interest in such studies was initiated by simulations of structure formation in the Universe, and that it was wonderful to see that direct measurements of gas masses of distant galaxies are possible today."

The results have been published in the Astrophysical Journal Letters of the American Astronomical Society (AAS), and have been highlighted by AAS Nova as one of the most interesting recent results to appear in journals published by them.

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Astronomers use the upgraded GMRT to measure the gas mass of galaxies in the distant Universe - Economic Times

At the centre of the Andromeda Galaxy the Milky Ways much larger next door neighbour lies a black hole with more than 4.1 million times the mass of the Sun. The supermassive black hole is truly a galactic powerhouse, destroying everything in its wake. While the black hole is 25,000 lightyears across space from Earth at the moment, scientists have warned Andromeda and the Milky Way will one day collide, which could spell the end for our planet.

Andromeda, which at 220,000 lightyears across is twice the size of the Milky Way, is approaching the our galaxy at around five million kilometres a year.

When the galaxies do meet, Earth could be flung into the centre of Andromeda, where its supermassive black hole would consume the planet.

Fabio Pacucci, an astrophysicist at Harvard University & Smithsonian Astrophysical Observatory, said during a Ted Talk: Unlike their stellar cousins, supermassive black holes arent wandering through space.

Instead, they lie at the centre of galaxies, including our own. Our solar system is in a stable orbit around a supermassive black hole that resides at the centre of the Milky Way, at a safe distance of 25,000 lightyears.

But that could change. If our galaxy collides with another, the Earth could be thrown towards the galactic centre, close enough to the supermassive black hole to be eventually swallowed up.

In fact, a collision with the Andromeda Galaxy is predicted to happen 4 billion years from now, which may not be great news for our home planet.

However, Mr Pacucci added that black holes get a bad rep, and said they are actually vital for the existence of life in the cosmos.

The Harvard astrophysicist continued: But before we judge them too harshly, black holes arent simply agents of destruction.

READ MORE:Black hole measuring just 1mm would destroy Earth

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Black hole horror: Earth to be consumed by monster black hole - astronomer warning - Express.co.uk