According to predominant theories of galaxy formation, the earliest galaxies in the Universe were born from the merger of globular clusters, which were in turn created by the first stars coming together. Today, these spherical clusters of stars are found orbiting around the a galactic core of every observable galaxy and are a boon for astronomers seeking to study galaxy formation and some of the oldest stars in the Universe.

Interestingly enough, it appears that some of these globular clusters may not have survived the merger process. According to a new study by an international team of astronomers, a cluster was torn apart by our very own galaxy about two billion years ago. This is evidenced by the presence of a metal-poor debris ring that they observed wrapped around the entire Milky Way, a remnant from this ancient collision.

The study, which recently appeared in the journal Nature, was led by Zhen Wan and Geraint Lewis (a Ph.D. astrophysics student and his professor at the University of Sydney, respectively) and included members from the Macquarie University Research Centre for Astronomy, the Observatories of the Carnegie Institution for Science, the ASTRO 3D center, the McWilliams Center for Cosmology, and multiple universities.

Their study was part of the Southern Stellar Stream Spectroscopic Survey (S5), an international collaboration dedicated to observing stellar streams in the Milky Way. Using the Anglo-Australian Telescope at the Siding Spring Observatory in New South Wales, Australia, the collaboration measured the speeds of the Phoenix Stream (a stream of stars in the Phoenix constellation) that appeared to be the remnants of a globular cluster.

Once we knew which stars belonged to the stream, we measured their abundance of elements heavier than hydrogen and helium; something astronomers refer to as metallicity, explained Wan in a recent Lowell Observatory press release.

To break it down, the oldest stars in the Universe are metal-poor because heavier elements like calcium, oxygen, phosphorous, iron, etc did not exist in abundance. Unlike hydrogen and helium (which were extremely plentiful in the early Universe) these elements formed in the interiors of stars sand were dispersed only after the earliest generation of stars collapsed and dispersed these elements when they exploded in supernovae.

In this respect, astronomers are able to discern the age of stars based on how metal-rich they are. Previous observations of globular clusters have found that their stars are enriched with heavier elements, which they obtained from previous generations of stars. As a result, astronomers have established a metallicity floor for globular clusters, a value that none of them can theoretically fall below.

However, the S5 collaboration noted that the metallicity of the Phoenix Stream (specifically, its iron-to-hydrogen content) sits well below this floor. In short, the Phoenix Stream represents the debris of the most metal-poor globular clusters discovered to date, making it distinct from the roughly 150 globular clusters that form a tenuous halo envelop the Milky Way today.

As Lowell Observatory astronomer Kyler Kuehn, one of the founders of the S5 collaboration and a co-author of the article, remarked:

We can trace the lineage of stars by measuring the different types of chemical elements we detect in them, much like we can trace a persons connection to their ancestors through their DNA. The most interesting thing about the remains of this cluster is that its stars have much lower abundance of these elements than any others we have seen. Its almost like finding someone with DNA that doesnt match any other person, living or dead. That leads to some very interesting questions about the clusters history that were missing.

We were really surprised to find that the Phoenix Stream is distinctly different to all of the other globular clusters in the Milky Way, added Wan. Even though the cluster was destroyed billions of years ago, we can still tell it formed in the early universe.

In short, the Phoenix Streams very existence indicates the existence of globular clusters that were below the metallicity floor. As to why none have been discovered so far, the answer may lie in the debris disk itself: they were destroyed in the early Universe as they were still merging with galaxies and galaxies merged with each other.

Of course, this is not yet a conclusive explanation for the origins of the Phoenix Streams progenitor cluster or where it sits in the evolutionary timeline of galaxies. Whats needed at this point is more observations and more evidence gathering to see if other progenitor clusters show the same levels of low metallicity.

There is plenty of theoretical work left to do, said co-author Geraint Lewis of the University of Sydney (and a co-author on the study). There are now many new questions for us to explore about how galaxies and globular clusters form, which is incredibly exciting.

Further Reading: Lowell Observatory, Nature

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A Globular Cluster was Completely Dismantled and Turned Into a Ring Around the Milky Way - Universe Today

Up to half the calcium in the Universe and that includes our bones and teeth is thought to come from exploding supernova stars, and researchers have now been able to get unprecedented insight at how these ultra-rare, calcium-rich supernovae reach the end of their lives.

The never-before-seen look at how these stellar explosions throw out so much calcium was carried out using deep space X-ray and infrared imaging, and fills in quite a few of the gaps in our scientific knowledge about the process.

Drawing together contributions from 67 authors across 15 countries, the resulting study suggests that the calcium-rich supernovae start off as compact stars that quickly lose mass at the end of their lives, giving off an outer layer of gas that exploding materials then collide with.

(Aaron M. Geller, Northwestern University)

"These events are so few in number that we have never known what produced calcium-rich supernovae," says astrophysicist Wynn Jacobson-Galan, from Northwestern University.

"By observing what this star did in its final month before it reached its critical, tumultuous end, we peered into a place previously unexplored, opening new avenues of study within transient science."

The supernova in question, SN 2019ehk, was first spotted by amateur astronomer Joel Shepherd in the Messier 100 (M100) spiral galaxy about 55 million light-years away from Earth. Very soon after the discovery was made, most of Earth's major telescopes were following it with transient events like this, speed is crucial.

What astronomers weren't expecting was the luminosity of the X-ray light that SN 2019ehk was giving off. Scientists quickly realised they were looking at a flood of high-energy X-rays flowing from the star and hitting the outer shell of gas, providing key clues to the materials that it was shedding and how much of the material there was.

The readings from the dying star helped scientists to work out what was happening: the reactions between the expelled materials and the outer gas ring were producing intensely hot temperatures and high pressures, leading to a calcium-producing nuclear reaction as the star tries to shed its heat and energy as quickly as possible.

"Most massive stars create small amounts of calcium during their lifetimes, but events like SN 2019ehk appear to be responsible for producing vast quantities of calcium and in the process of exploding disperse it through interstellar space within galaxies," says astronomer Rgis Cartier, from the National Optical-Infrared Astronomy Research Laboratory (NOIRLab) in the US.

"Ultimately this calcium makes its way into forming planetary systems, and into our bodies in the case of our Earth!"

It's because these stars are so important in calcium production that scientists have been so keen to take a look at them something that has proved difficult (even Hubble missed SN 2019ehk). The explosion at the centre of the new study is responsible for the most calcium ever seen emitted in a singular observed astrophysical event.

Being able to see the inner workings of this type of supernova will open up new areas of research and give us a better idea of how the calcium in our bones and teeth and everywhere else in the Universe came to be.

It's also a great example of the international scientific community working together to capture and record something of great importance. Just 10 hours after the initial bright burst was spotted in the sky by Joel Shepherd, some of the best telescopes we have were ready to record what happened next.

"Before this event, we had indirect information about what calcium-rich supernovae might or might not be," says astrophysicist Raffaella Margutti, from Northwestern University. "Now, we can confidently rule out several possibilities."

The research has been published in The Astrophysical Journal.

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Here's How Exploding Stars Forged The Calcium in Your Teeth And Bones - ScienceAlert

Soon, the James Webb Space Telescope (also known as JWST or Webb) will expand our views of the sky. Astronomers will use the new telescope to observe previously unseen regions of space, ranging from the galaxies that formed right after the Big Bang to the youngest star systems that are forming today.

Earth is minuscule in the scale of the universe. So far, astronomers have discovered giant planets, supermassive black holes, hypergiant stars, superclusters of galaxies and other large objects in between. And thats while observing just a small sliver of the universe with the Hubble Space Telescope. It is hard to predict what Webb will ultimately discover.

Its a new instrument, the largest telescope ever built for space, says Jon Arenberg, chief engineer for Space Science Missions at Northrop Grumman. Well be able to collect data that we have not gotten our hands on before, including observing the early universe, in particular.

Astronomers have already discovered some humongous objects, and JWST could soon uncover even more giants in space.

By having this new instrument that that can observe even more galaxies than weve seen before, we will be able to look for structures and groups of these galaxies in places weve never looked, Arenberg explains.

Contemplating the size of objects in space compared to our tiny home on Earth could make your head spin, but Arenberg finds comfort and pride in JWSTs mission of discovery.

I feel empowered, enlightened, illuminated not tiny, Arenberg says. He adds, The scale of the universe is huge. But so is our planet compared to me, and I dont feel small or insignificant here on Earth.

Its a straightforward question with a nebulous answer. First, it depends on how you define size by mass or volume. A giant cloud of gas, for example, is enormous in volume but relatively small in mass (it doesnt contain much matter). Black holes, on the other hand, are defined by infinitely small volume with infinite density, according to Sky and Telescope.

Secondly, well have to consider what counts as an object. If a group of particles is an object, what about a group of galaxies?

One thing is certain, the largest objects in space are much, much larger than Earth. They just appear small because they are so far away from us. Here are some of the largest known objects in the universe.

Jupiter is the largest planet in our solar system. Its a giant ball of gas that could fit all the other planets in the solar system inside it. According to NASA, more than 1,300 Earths would fit inside Jupiter.

But Jupiter is tiny compared to HAT-P-67 b, an exoplanet (orbiting a different star than our sun) that astronomers first observed in 2017. Astronomy.com reported that this newly discovered planet is 2.08 times the size of Jupiter, although it isnt as dense, weighing in at 60% less than Jupiters mass. Its the biggest, fluffiest planet we know of so far.

According to NASA, our sun is a million times the size of the Earth. But to put this in context, if our entire solar system was the size of a quarter, the sun would be a microscopic speck of dust on that quarter.

As big as a million times Earth sounds, Space.com points out that our sun is only an average-sized star. Scientists have discovered hypergiant stars such as UY Scuti, which could fit more than 1,700 of our suns in its radius.

Unlike stars, black holes dont take up space, but they are dense. The largest black hole in our neighborhood, Sagittarius A*, is 4 million times more massive than the sun, according to MIT Technology Review. Meanwhile, 700 million light-years away from Earth, a galaxy called Holm 15A contains the largest known black hole in the observable universe. Astronomers used data gathered by the Very Large Telescope in Chiles Atacama Desert to run simulations that map out this distant galaxy. Their models suggest that Holm 15A has a supermassive black hole that is at least 40 billion times more massive than the sun.

Although structures might not technically count as objects according to astrophysics terminology, from a logical perspective, a structure is the largest object in the universe.

Gravity can make galaxies clump together in space. Multiple galaxies form clusters, which can form superclusters, and even long lines of galaxies called walls, according to New Scientist. The largest known structure is the Baryon Oscillation Spectroscopic Survey Great Wall. This superstructure is made of 830 galaxies bound by gravity that swirl together in a wall that is a billion light-years across.

JWST could help astronomers discover even larger superstructures.

We will be able to collect images and spectra from hundreds or tens of thousands of galaxies. This will help astronomers identify groups of galaxies, says Arenberg.

Great societies have always pursued the unknown, explains Arenberg. He says, Increasing our scientific knowledge is not only good in and of itself, but its the basis of our economy and our security.

All these records for the largest objects in space could soon be broken as new, powerful telescopes reveal hidden spots in the universe.

Peering into deep space with JWST is the next step in a long legacy of exploration.

Arenberg says, Americans have always prided themselves on discovery and the frontier since the beginning of the country. And this is just carrying on that legacy from our ancestors. We should dare to do these amazing things and inspire ourselves and inspire the next generation.

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Could JWST Discover the Largest Object in the Universe? Now. Powered by - Now. Powered by Northrop Grumman.

The researchers said they had found the largest crater in the solar system. It was formed due to the impact of a huge asteroid, which was moving at a speed of 20 km/s.

Scientists have discovered the largest impact crater in the entire solar system. Astronomers found it on Jupiters largest moon, Ganymede. Most of the celestial body is covered with scars from impacts, so it was difficult for researchers to find this crater.

Astronomers have relied on observational data from many past NASA missions. They studied the massive Moon, which is larger than Mercury, the smallest planet. In particular, they concentrated on the grooves that appear on the surface of celestial bodies.

Researchers have learned that these grooves indicate powerful blows from all sides of Ganymede. But upon re-examining the structures, the scientists behind the new research suggested that the structure was an impact crater.

The researchers also carried out complex simulations on a very powerful computer at the National Astronomical Observatory of Japan. These data indicate that, most likely, a celestial body collided with a huge asteroid. Its diameter is about 15 km., It moved at a speed of 20 kilometers per second. The researchers suggest that particles of a celestial body can be found in the crater.

They want to confirm this theory scientists can do it when the European Space Agencys JUICE probe reaches the moon in 2029. Its launch is scheduled for 2022.

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Astronomers find the largest impact crater in the solar system - FREE NEWS

So named for its resemblance to the winged insect, the "butterfly" is actually a planetary nebula -- a giant cloud of gas that forms around an ancient star that hasn't yet exploded. The European Space Observatory's (ESO) aptly named Very Large Telescope, stationed in host country Chile, recently captured a vibrant image of the interstellar object.

It's known as NGC 2899 (NGC stands for New General Catalogue, which lists nebulae and other astral bodies like this one). It's located somewhere between 3,000 and 6,500 light years away from Earth in the constellation Vela, which is visible in the Southern Hemisphere.

This planetary nebula isn't long for this universe. Ultraviolet radiation lights up the shells of gas surrounding the star and causes them to shine quite brightly, the ESO said -- but only for a few thousand years before they break up. That's a relatively short life span in astronomy.

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See the 'space butterfly' astronomers captured from thousands of light years away - CNN

If you want the clearest view of the night sky, you'll have to pack a warm jacket.

Dome A, or Dome Argus, an ice dome perched high on the Antarctic Plateau, could be the ideal place to get a clear view of the stars from Earth, according to a new study conducted by an international team of researchers. A telescope situated at that remote location, thought to be the naturally coldest place on Earth, could reveal clearer, better night sky views than the same telescope located anywhere else.

"A telescope located at Dome A could out-perform a similar telescope located at any other astronomical site on the planet," University of British Columbia astronomer Paul Hickson, a co-author of the study, said in a statement.

Related: Night sky, August 2020: What you can see this month [maps]

"The combination of high altitude, low temperature, long periods of continuous darkness, and an exceptionally stable atmosphere makes Dome A a very attractive location for optical and infrared astronomy. A telescope located there would have sharper images and could detect fainter objects," Hickson said.

The chilly location, which is about halfway between the South Pole and the eastern coast of Antarctica, about 746 miles (1,200 kilometers) inland and with an altitude of 2.5 miles (4 kilometers), makes for an ideal observing spot for a number of reasons.

For one: it has very weak turbulence. In astronomy, atmospheric turbulence can seriously reduce a telescope's image quality. It makes stars "twinkle," and the measurement of this effect is described as "seeing." Less turbulence (or the lower the "seeing" measurement) is considered better, and at Dome A it is fairly low.

While observatories in locations along the equator at locations including Chile and Hawai'i have "seeing" measurements between 0.6 and 0.8 arcseconds, the Antarctic typically has much lower ranges. For example, Dome C, another Antarctic location has a "seeing" range between 0.23 and 0.36 arcseconds.

But, the authors estimate in this study, the lowest part of the atmosphere is thinner at Dome A than at Dome C. Because of this difference, the researchers calculate that Dome A has nighttime seeing ranging from 0.31 to as low as 0.13 arcseconds, which is astoundingly low.

The researchers found that the measurements taken from Dome A, which were taken at a height of 26 feet (8 meters), were much better than those from Dome C, which were taken both at 26 feet (8 meters) and even higher up at 66 feet (20 meters).

Now, with seriously frigid temperatures, frost is an issue that presents itself to astronomers looking to set up a telescope at the site. But, despite the technical difficulties that pop up when trying to make observations at a site this remote and cold, this team of researchers thinks that Dome A could lend itself to some pretty spectacular skywatching.

The researchers were able to have a telescope work in Antarctica completely automatically for seven months. They believe that other instruments could withstand the Antarctic temperatures, which have been said to fall as low as 90 C (130 F) to 98 C (144 F).

This work was published July 29 in the journal Nature.

Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.

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The best place to see stars from Earth also happens to be the coldest place on the planet - Space.com

A study led by researchers at the Instituto de Astrofsica de Canarias (IAC), making comparison between the discs of several pairs of spiral galaxies, active and non-active, concludes that in the discs of the former the rotational motion of the stars is of greater importance. This study, just accepted for publication in Astronomy & Astrophysics Letters, is the first evidence for large scale dynamical differences between active and non-active galaxies in the local universe. The astronomers participating are from the Instituto de Astrofsica de Canarias (IAC) and the University of La Laguna (ULL); as well as the NatiAstronomical First: Differences Detected Between Discs of Active and Non-active Galaxiesonal Autonomous University of Mexico (UNAM), the Complutense University of Madrid (UCM) and the Instituto de Astrofsica de Andalucia (IAA).

There is now evidence that the supermassive black holes at the centers of the majority of galaxies have a basic influence on their evolution. In some of them, the black hole is ingesting the material surrounding it at a very high rate, emitting a large quantity of energy. In those cases we say that the galaxy has an active nucleus (AGN). The material which feeds the AGN must initially be quite distant from the nucleus, in the disc of the galaxy, rotating around its center. This gas must, one way or another, have been braked in order to fall into the central zone, a process known as loss of angular momentum.

Image illustrating the comparison between an active spiral galaxy (orange box) and its non-active twin (blue box). Credit: Gabriel Prez Daz, SMM (IAC)

Studying the mechanisms which control the relation between the active nucleus and the rest of the galaxy -explains Ignacio del Moral Castro, a doctoral student in the IAC and the University of La Laguna (ULL) and first author of the article- is necessary to understand how these objects form and evolve, and to be able to throw light on this question we need to compare active and non-active galaxies. With this purpose, the main idea of my doctoral thesis is centred on the study and comparison of galaxies which are almost twin, but with the difference being nuclear activity.

The work has consisted of comparing the dynamics of the galactic discs of various active/non-active pairs. The researchers used data from the CALIFA survey (Calar Alto Legacy Integral Field Area). This contains spectroscopic data over complete 2D fields for more than 600 galaxies, taken at the Calar Alto Observatory in Almera, which allow observations of virtually the whole of each galaxy, so that its global characteristics can be studied.

Previously, in the majority of studies the procedure used was the identification of a sample of active galaxies within a large survey, which were then compared to the rest of the galaxies in the survey having similar properties that do not show nuclear activity. However, this time, the researchers used a novel method: they performed one-to-one comparisons. Firstly, they identified active spiral galaxies in the CALIFA sample, and for each of them they looked for a non-active galaxy which had equivalent global properties, i.e. with the same mass, brightness, orientation and so on, and very similar in appearance.

Using this method the team put forward two scenarios to explain the dynamical differences between active and non-active galaxies. In the first, the explanation would be that it is the trace of the angular momentum transfer between the gas which has fallen into the centre and the material which remains in the disc. The second attributes the difference to the infall of gas from outside, via the capture of small nearby satellite galaxies, in which case, this capture should occur more frequently in the active galaxies. Both scenarios are compatible with this result and they are not mutually exclusive.

The result surprised us; we really didnt expect to find this type of differences on a large scale, give that the duration of the active phase is very short in comparison with the lifetime of a galaxy, and with the time needed to produce morphological and dynamical changes, says Begoa Garca Lorenzo, and IAC researcher, and a coauthor of the article.

Up to now we thought that all galaxies go through active phases during their lifetimes, but this result could mean that this is not the case, which would imply a major change to current models, adds Cristina Ramos Almeida, also an IAC researcher and coauthor of the article.

Reference: Larger R in the disc of isolated active spiral galaxies than in their non-active twins byI. del Moral-Castro, B. Garca-Lorenzo, C. Ramos Almeida, T. Ruiz-Lara, J. Falcn-Barroso, S.F. Snchez, P. Snchez-Blzquez, I. Mrquez and J. Masegosa, 14 July 2020, Astronomy & Astrophysics Letters.DOI: 10.1051/0004-6361/202038091arXiv: 2006.12654

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Astronomical First: Differences Detected Between Discs of Active and Non-Active Galaxies - SciTechDaily

The evidence that water once existed on Mars is unmistakable: The planet is covered in valleys that appear carved by flowing water. For decades, these epic ravines and branching riverbeds beckoned planetary scientists to imagine a 3.5-billion-year-old world that was both warm and wet, covered with lakes and rivers possibly hosting an environment conducive to life.

But new research suggests Mars might not have been the balmy paradise scientists once envisioned. Now, the evidence seems to suggest that rivers may not have covered its surface, but instead flowed deep under large sheets of ice.

To come to this conclusion, the researchers performed a statistical analysis of the shapes and patterns of 66 networks of valleys on Mars, which are composed of over 10,000 individual valleys. They then compared these to similar features on Earth.

They found that 14 of the martian sites appeared to have characteristics reminiscent of above-ground rivers. But 31 seemed to be carved out by either glacial or subglacial meltwater, more like terrain found near former glaciers on Earth.

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Rivers on ancient Mars may have flowed beneath sheets of ice - Astronomy Magazine

Astronomers were already concerned about SpaceX's plan to put 25,000 satellites in orbit. Andas of July 30, there's yet another reason for astronomers to believe that ground-based observational astronomy is about to become much more difficult: Amazon's Project Kuiper.

On Friday,news broke thatthe Federal Communications Commission approved Amazon's plans for its ambitious Kuiper constellation, which includes sending 3,236 satellites into three different altitudes in orbit.

The FCC's approval is a big regulatory stepand gives Amazon permission to move forward with the launch when they're ready. The satellites are part of Amazon's effort to provide satellite-based internet to everyone in the United States, an endeavor that's been positioned as havinga charitable and community-oriented mission.

"This investment will create jobs and infrastructure around the United States, build and scale our ground network, accelerate satellite testing and manufacturing, and let us deliver an affordable customer terminal that will make fast, reliable broadband accessible to communities around the world," Amazon stated in a blog post.

But many astronomers who depend on a clear sky from Earth to observe the universe, are wondering at what cost? Indeed, the more satellites in Earth's orbit, the more difficult it will be for astronomers to make accurate and unobstructed observations. Alexandre Lazarian, a professor of Astronomy at the University of Wisconsin - Madison, told Salon he believes the case of Amazon's commercial satellites " is one of many that hinders our exploration of the universe."

"I believe that some aspects of the civilization progress makes the work of observers more difficult," Lazarian said. "This includes light pollution, radio noise and also satellites."

On the other hand, Lazarian said that technological progress is opening up new horizons for astronomy.

Avi Loeb, chair of Harvard's astronomy department, told Salon via email that astronomers have long escaped light pollution by placing their telescopes far from cities. However, new communication satellites like Amazon's "will reflect sunlight and create a city of lights in the sky that no telescope on Earth can escape."

"The biggest impact will be on telescopes that survey large areas of the sky on a routine basis, such as the Vera Rubin Observatory that will see its first light in the coming year and is planned to conduct the extensive LSST survey, covering the southern sky every few days in search for transient events," Loeb told Salon. "The satellite constellations will leave streaks of bright on the CCD detectors of the observatory, making it difficult to separate real astronomical sources from their bright contaminating light."

In May, the Vera Rubin Observatory released a statement of concern regarding the launch of SpaceX satellites, and the plans of other companies like Amazon.

"The Vera C. Rubin Observatory science community is concerned about the increasing deployment of communications satellite constellations which, if unchecked, could jeopardize the discoveries anticipated from Rubin Observatory when science operations begin in 2022," the statement read. "Because Rubin Observatory is uniquely impacted by these satellite constellations, its science team is taking an active role in pursuing mitigation strategies to reduce the impact of the satellites on Rubin Observatory science."

Indeed, such efforts to send internet-based satellites have already begun. In late May 2019, SpaceX launched the first 60 of itsof 42,000 communications satellites for the planned Starlink constellation. Since then, Elon Musk's company has launched several more groups of 60 satellites. While satellites aren't necessarily a new problem for astronomers, the brightness of the SpaceX-launched satellites have been a big concern for astronomers.

In January 2020, a study published in the journal Astronomy & Astrophysics analyzed the potential impact of commercial satellites like those by SpaceX and Amazon and found that large telescopes will likely be "moderately affected."

"The results suggest that large telescopes like ESO's VLT and upcoming ELT will only be moderately affected, although some science cases may require the implementation of mitigation measures, such as scheduling of the observations or interruption of the exposures to allow a satellite to cross the field of view," the study concluded.

Amazon said it will invest more than $10 billion in Project Kuiper in the company's statement. While there are no specific launch dates yet, under the FCC's approval the company must launch half of the constellation by 2026 to keep its FCC license, and the remaining satellites by 2029.

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Move over, SpaceX Amazon is sending its own satellites into orbit - Salon

Illustration shows how the stars motion around the center of mass between it and the planet causes a wobble in its motion through space. The VLBAs ability to detect this minuscule effect revealed the presence of the planet. Credit: Bill Saxton, NRAO/AUI/NSF

Using the supersharp radio vision of the National Science Foundations continent-wide Very Long Baseline Array (VLBA), astronomers have discovered a Saturn-sized planet closely orbiting a small, cool star 35 light-years from Earth. This is the first discovery of an extrasolar planet with a radio telescope using a technique that requires extremely precise measurements of a stars position in the sky, and only the second planet discovery for that technique and for radio telescopes.

The technique has long been known, but has proven difficult to use. It involves tracking the stars actual motion in space, then detecting a minuscule wobble in that motion caused by the gravitational effect of the planet. The star and the planet orbit a location that represents the center of mass for both combined. The planet is revealed indirectly if that location, called the barycenter, is far enough from the stars center to cause a wobble detectable by a telescope.

Side-by-side animations of the star and planet orbiting their common center of gravity (barycenter), and of the pair moving through space as they orbit, creating the stars wobble that revealed the planet. Credit: Bill Saxton, NRAO/AUI/NSF

This technique, called the astrometric technique, is expected to be particularly good for detecting Jupiter-like planets in orbits distant from the star. This is because when a massive planet orbits a star, the wobble produced in the star increases with a larger separation between the planet and the star, and at a given distance from the star, the more massive the planet, the larger the wobble produced.

Starting in June of 2018 and continuing for a year and a half, the astronomers tracked a star called TVLM 51346546, a cool dwarf with less than a tenth the mass of our Sun. In addition, they used data from nine previous VLBA observations of the star between March 2010 and August 2011.

Artists conception of dwarf star TVLM-513-46546 and its newly-discovered planetary companion. Credit: Luis A. Curiel Ramirez

Extensive analysis of the data from those time periods revealed a telltale wobble in the stars motion indicating the presence of a planet comparable in mass to Saturn, orbiting the star once every 221 days. This planet is closer to the star than Mercury is to the Sun.

Small, cool stars like TVLM 51346546 are the most numerous stellar type in our Milky Way Galaxy, and many of them have been found to have smaller planets, comparable to Earth and Mars.

Artists conception of dwarf star TVLM-513-46546 and its newly-discovered planetary companion. Credit: Luis A. Curiel Ramirez

Giant planets, like Jupiter and Saturn, are expected to be rare around small stars like this one, and the astrometric technique is best at finding Jupiter-like planets in wide orbits, so we were surprised to find a lower mass, Saturn-like planet in a relatively compact orbit. We expected to find a more massive planet, similar to Jupiter, in a wider orbit, said Salvador Curiel, of the National Autonomous University of Mexico. Detecting the orbital motions of this sub-Jupiter mass planetary companion in such a compact orbit was a great challenge, he added.

More than 4,200 planets have been discovered orbiting stars other than the Sun, but the planet around TVLM 51346546 is only the second to be found using the astrometric technique. Another, very successful method, called the radial velocity technique, also relies on the gravitational effect of the planet upon the star. That technique detects the slight acceleration of the star, either toward or away from Earth, caused by the stars motion around the barycenter.

The Very Long Baseline Array is a continent-wide radio telescope system spanning the distance from Hawaii in the Pacific to St. Croix in the Caribbean. It provides astronomers with extremely high resolving power, the ability to see fine detail. Credit: J. Hellermann, NRAO/AUI/NSF

Our method complements the radial velocity method which is more sensitive to planets orbiting in close orbits, while ours is more sensitive to massive planets in orbits further away from the star, said Gisela Ortiz-Leon of the Max Planck Institute for Radio Astronomy in Germany. Indeed, these other techniques have found only a few planets with characteristics such as planet mass, orbital size, and host star mass, similar to the planet we found. We believe that the VLBA, and the astrometry technique in general, could reveal many more similar planets.

A third technique, called the transit method, also very successful, detects the slight dimming of the stars light when a planet passes in front of it, as seen from Earth.

Very Long Baseline Array (VLBA) astrometry detected a wobble in the proper motion of a small star caused by the gravitational effect of a Saturn-sized exoplanet. First radio discovery of an exoplanet by this technique. Credit: NRAO/AUI/NSF

The astrometric method has been successful for detecting nearby binary star systems, and was recognized as early as the 19th Century as a potential means of discovering extrasolar planets. Over the years, a number of such discoveries were announced, then failed to survive further scrutiny. The difficulty has been that the stellar wobble produced by a planet is so small when seen from Earth that it requires extraordinary precision in the positional measurements.

The VLBA, with antennas separated by as much as 5,000 miles, provided us with the great resolving power and extremely high precision needed for this discovery, said Amy Mioduszewski, of the National Radio Astronomy Observatory. In addition, improvements that have been made to the VLBAs sensitivity gave us the data quality that made it possible to do this work now, she added.

Curiel, Ortiz-Leon, Mioduszewski, and Rosa Torres of the University of Guadalajara in Mexico, reported their findings in the Astronomical Journal.

Reference: An Astrometric Planetary Companion Candidate to the M9 Dwarf TVLM 51346546 by Salvador Curiel, Gisela N. Ortiz-Len, Amy J. Mioduszewski and Rosa M. Torres, 4 August 2020, Astronomical Journal.DOI: 10.3847/1538-3881/ab9e6e

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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Saturn-Sized Exoplanet Discovered by the Gravitational Wobble in the Small, Cool Star It Orbits - SciTechDaily

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Astronomy Apps Market Expected to Witness the Highest Growth 2025 - AlgosOnline

Exoplanets have been a particularly hot topic of late.

More than 4,000 of them have been discovered since thefirstin 1995. Now one more can potentially be added to the list. This one is orbiting Gliese 3470, a red dwarf star located in the constellation Cancer. What makes this discovery particularly interesting is that this planet wasn't discovered by any professional astronomers using high tech equipment like theKepler Space Telescope. It was found entirely by amateurs.

Not just any amateurs though they are part of an effort organized by Alberto Caballero of theThe Exoplanets Channelon Youtube.

The group is called theHabitable Exoplanet Hunting Project(HEHP) and bills itself as "the first international program coordinated by amateur astronomers to search for habitable exoplanets."

The group "includes more than 30 amateur and professional observatories located in more than 10 countries across 5 continents". The group coordinates efforts across all these observatories by observing the same star concurrently for significant lengths of time.

In the case of the new planet, which being called Gliese 3470c, most of the observational data came from an amateur astronomer named Phillip Scott located in Kiowa, Oklahoma, about 2 hours southeast of Oklahoma City.

The observations were done using his own personal 12.5 inch telescope, that he built a observatory in his backyard to house. They were carried out between the months of December 2019 and May 2020.

The data collected during that period was analyzed using a technique known astransit photometry, which watches for changes in a star's brightness. The team observed three transits of the potential planet, which they say may have an orbital period of 66 days.

Given the size of Gliese 3470, that would put the planet around the point of 'Earth's Equivalent Radiation', making it possible that the planet resides in the habitable zone of the star.

The planet itself is too big to be an Earth analogue though, coming in at more than 9.2 times the radius of Earth, placing it more akin to the size of Saturn. The team also can't rule out that the planet might actually have a faster orbit that they proposed, as data was not available for some other times when it might have been transiting if the orbital period was shorter.

The planet will indeed need further confirmation, both of its orbital period and also of its existence in general. As is common with exoplanet discoveries, the HEHP team published their findings, along with a Google drive link to theirdata, and are actively encouraging other astronomers to observe Gliese 3470 to confirm their new planet.

Let's hope that their discovery is not only confirmed, but also inspires more amateur astronomers to pick up the torch of searching for habitable exoplanets.

If you want to join the organization in their efforts, you can find more detailshere.

This article was originally published by Universe Today. Read the original article.

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Amateur Astronomers Find a Saturn-Sized Planet in The Habitable Zone of a Distant Star - ScienceAlert

When I was a kid, I loved space. I loved it so much that after seeing the movie Space Camp, I begged my parents to let me go to NASAs Space Camp. I never did get to go, and after a while, my love for astronomy seemed to wane; one of those interests you have as a child that burns brightly for a while, intense and deep, and then eventually cools off and darkens. Sometimes, years later, if youre lucky, it gets reignited. Books are a great way to dive back into an old passion, and these books about and related to astronomy are a great way to get back into the subject, or even good introductions to it. If youre looking for even more out-of-this-world (sorry, I couldnt resist) suggestions, check out these books on astrophysics and women in space.

This is a gorgeously illustrated book that combines mythology, science, and art to create an engaging text about the night sky. It includes the Milky Way, the sun, the moon, constellations, planets, deep space, and more. Oseid writes in an accessible way thats perfect for both kids and adults, and the book is chock-full of information with visuals that nicely complement the text.

Dr. Adern-Pocock is a big fan of the moonand this book showcases her passion well. This is a comprehensive, detailed book about all things lunar: from moon basics to a cultural examination of the moon within our culture, to what we know about the moon right now, and finally, to the future of lunar exploration, this book has it all. Even when discussing the most minute details of lunar astronomy, Dr. Adern-Pocock makes these details fascinating and easy to understand.

This is more astronomy-adjacent, but bear with me here. Dr. Sara Seager is a planetary scientist, and in this memoir, not only do we learn how she came to love astronomy, but we also see how it grounded her (no pun intended) after her husband died when she was 40, leaving her with two small children. This is a story of connection and discovery, of figuring out a way through grief, and the magic not just of the workings of the galaxy, but of the workings of relationships right here on Earth.

This might be one of the more complicated books on the list, but its well worth it. Dr. Michio Kaku, a physicist and futurist, has written multiple astronomy books. This one looks at the idea of a sustainable civilization in outer space, through robotics, nanotechnology, and biotechnology. He doesnt stop at just exploring the galaxy, thoughhe also discusses wormholes, parallel universes, and the multiverse. Dr. Kakus enthusiasm and excellent writing makes this a dense but enjoyable read if you want to take a deep dive into the universe.

Theres a reason the BBC chose this book as one of the Best Astronomy and Space Books of 2019. Humorous and full of interesting information about the planets, this is an extensive but easily readable book that looks at the solar system. It delves into the history of the planets, planetary exploration, satellites, and much more. Murdin brings each planet to life with fun and fascinating details about them.

Solvig is a commercial deep-sea diver, but has secretly wanted to be one of the first people on Marsand she might get her chance when shes one of 100 people shortlisted for the Mars Project. Theres a tradeoff, though: to do what shes always wanted to do, she would have to leave everything else behind forever. This book looks at the questions many women grapple with: starting a family, the tradeoffs between work and home life, compromise in relationships, and what can feel like the weight of ambition.

A storybook collection that can be enjoyed by the entire family, this book contains myths and legends from all over the world about the constellations. People have been making up stories about the constellations for thousands of years, and this collection contains a variety of tales from all over, including the South Pacific, Ancient Greece, China, India, and North and South America. Paired with beautiful illustrations, these stories bring the stars to life.

Dr. Sarah Stewart Johnson has always been fascinated by Mars, and this book traces not only her personal fascination with the planet, but also her research work about Mars, as well as the stories of others who have been fascinated by the planet. While the book may be about searching for life on a planet that at first glance seems very different from Earth, its also about what we hope to find in our own lives.

If you havent read this yet, add this to your TBR pile immediately. Theres a reason this is destined to be a classic, IMO. This book follows the human computers who helped get astronauts onto the moon, particularly four Black women: Christine Darden, Mary Jackson, Dorothy Vaughn, and Katherine Johnson. Jim Crow laws were still in effect, and this book looks at varying intersectionalities: the mathematicians being female, as well as Black, at a time when both groups were seen as less than, compared to white men. The book follows them for almost 30 years, and is a must-read if you want to learn more about NASAs history.

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9 of the Best Books About Astronomy - Book Riot

In 2014, a human capital development project was initiated through a joint UK-South Africa Newton Fund to help drive economic development in Africa. Development in Africa with Radio Astronomy (DARA) project aims to develop high tech skills using radio astronomy in some African countries and also provide a pool of talented young people who have been inspired by astronomy to play a leading role in the emergence of new economies.

Space in Africa had a chat with Prof. Melvin Hoare of the University of Leeds. He is leading the DARA project and related projects that provide training and entrepreneurial skills to the first generation of radio astronomers in Africa. With a research interest focusing on the formation of massive stars, Prof Hoare is on the Science Working Group for the Square Kilometer Array (SKA) project and chair the Consortium of Universities for Goonhilly Astronomy (CUGA) project.

The hosting of the Square Kilometre Array radio telescope in South Africa played a crucial role in Professor Hoares decision to set up DARA. A precursor project, the African VLBI Network, includes the deployment of a network of radio telescopes across the eight countries (SKA AVN partners of South Africa are: Botswana, Ghana, Kenya, Madagascar, Mauritius, Mozambique, Namibia, and Zambia.). The first of these radio telescopes, upcycled from a defunct 32-m telecoms dish, was inaugurated in Ghana.

In 2018, the DARA project won the Better Satellite World Award alongside Goonhilly Earth Station, its commercial partner. The SSPIs Better Satellite World Awards programme celebrates innovation in space and satellite sector by honouring established companies as well as disruptors globally, and particularly in the UK and Europe, for their role on helping make our world a more prosperous, healthier, better-educated, more sustainable and inclusive home for all humankind.

What initiated the DARA project?

I was following the whole SKA project, and from a scientific point of view, I was interested in the array of dishes proposed to be built in Africa. Then we started looking for collaborations in Africa from that perspective. A couple of us visited Africa to make the collaboration, and we saw the whole idea behind the radio dishes network project which got South Africa and Ghana talking. Around that period, I got an email regarding a UK-Ghana collaboration grant and thinking about what Ghana and South Africa were doing; we set out to fill the gap in training people to operate and use telescope dishes across Africa. South Africa was already training some people from the partner countries, but not enough for sustainable radio astronomy groups.

It was an opportunity to combine my deep interest in Africa with my day job at the University. Ever since then, it has been an exciting journey. After checking the guidelines with the UK Royal Society, we applied for the grant, got it and started implementation with Ghana. After this period, the British government launched the Newton Fund for developmental projects and programs which you can use for scientific collaborations as far as it is addressing a development problem. We then started trying to figure out how training radio astronomers will help the economy. We were already involved in a project turning a dish into a telescope in the UK, and we have seen companies do this around here, which was like the Ghana situation.

We linked the whole project with commercial space sector and brought in one of the companies named Goonhily Earth Station Ltd. We then teach people in radio astronomy and train them to translate the knowledge into other industries such as SatCom, Remote Sensing and Big Data industry.

Please give us an overview of your activities and success stories

We started with Ghana, then expand to 4 countries, and now we operate in eight countries in Africa. DARA currently runs a basic training programme in radio astronomy in Botswana, Kenya, Madagascar, Mozambique, Mauritius, Namibia, Zambia and Ghana. Today we have trained up to 260 people across the continent; however, things are currently on hold due to the ongoing pandemic.

At the top level, its a joint UK/South Africa project because South Africa provided resources to match the UKs Newton funding. In each country, we take ten students per year, people who have already graduated bachelors; and then we give them an introduction to radio astronomy course. The basic training is eight weeks, spread over a year, including four weeks at the telescope site for hands-on experience. We also give computer programming skills in Python. In the final weeks, we go out and apply these to teach how to perform data reduction for radio astronomy using Linux, Python and other software. We also fund masters and PhD in the UK. We have about 20-30 now.

What do you consider as the most significant contributions of DARA project to Astronomy development in Africa?

Capacity development is vital, and we have made a significant impact on this. Some of the PhD students are rounding up now, and they are returning to their respective countries. We hope people come out of the program and work at regions where these telescopes are being developed. Hopefully, the Universities across Africa will also be hiring these people so they can start implementing academic astronomy programs across the countries. The goal is for them to be self-sustainable, so they operate the facilities in Africa, create related business and create jobs.

We are also committed to addressing developmental challenges in these countries with knowledge of Astronomy and associated skills. For example, we had one of the training in Zambia, and one of the participants with a background in environmental engineering realized he could use data from satellites to improve his companys business operations. He literally got the job because he was trained on the DARA project, which impressed the selection panel. We have another person in Zambia trying to improve GPS connectivity in the country.

We have also hired a part-time business consultant who advises DARA trainees who have gone through the training to develop their business plans and all.

Are you incubating startups from this program?

We are not incubating, but advising, we have worked with Office for Astronomy Development (OAD) in the past to provide some funding like 5,000 to execute projects. In Kenya, for example, a project implementing Astro-tourism got the grant.

Why the eight countries and not entire Africa?

The countries were pre-selected due to the SKA partnership. Ghana is the only place with a dish; other countries are still waiting. The initial plan was to convert some of the dishes in other countries.

What role do you think Astronomy plays in the development of the African region?

It is one of those topics that get young people excited. Astronomy is a perfect tool to get young people interested in science, and you can use it as a hook to get people into STEM.

Most people who study Astronomy and Physics in Africa end up jobless and some transition into other fields because of limited opportunities in the area. How do you think this can be addressed?

It surprised me when I first went to Africa, and Ive also heard this from professors in Africa. It is similar in Europe but maybe a little different. For example, we graduate 40 students in a year in my program in the UK, and most dont end up in the field. Even in Europe, they all go up into various things, some start their business, some transition into other industries and all. There is a lot of talk about Africa skipping into the 4th industrial revolution, going into the world of big data and all and I think Astronomy can play a useful role in this primarily because the knowledge can be used in other industries.

What are the future plans for DARA project in Africa?

We are coming to the end of the funding, but due to the ongoing pandemic, we expect it to be extended by a year till 2022. We need to find more funding if we want to continue, and we are still waiting for the UK government to set out their future spending plans. So far, we have had basic training and gotten people into masters and PhD programs. In the future, we want to fund Post-doctoral fellowships.

We also want to work more with African universities, support in supervising masters and PhD projects, help develop curriculum and do other research with them. Due to the SKA project, Africa is where radio astronomy will be in the future. We believe SKA should not be some giant project dropped on Africa and used by wealthy nations across the world. We want to ensure Africa has the needed talents for the project, create a bunch of jobs and high-tech industries.

To learn more about DARA project and to explore potential collaboration, visit the DARA website.

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Prof Melvin Hoare is Driving Development in Africa with Radio Astronomy - Space in Africa

It looks set to be a great month for stargazers across the country, with some of the best astronomical events taking place over the next few weeks.

From the stunning Delta Aquarids Meteor Shower to an out-of-this-world view of Mercury, July has been an epic month for show-stopping celestial events.

But luckily for those who may have missed seeing any, August also has a stellar line-up of dazzling astronomical displays to look forward to.

Not only will space enthusiasts be in for a chance to see the planet Venus, but will also be treated to two very special meteor showers!

Best of all, most will all be easy to spot in the sky without needing to fork out for any high-tech camera or telescopes.

Scroll down to see whats ahead to get excited about over the next few weeks.

On this night, the moon will be fully illuminated as it appears on the opposite side of the earth as the sun, resulting in a full moon.

In early native American tribes, this particular full moon was often called sturgeon moon because large sturgeon fish of the Great Lakes and other major lakes were more easily caught around this time of year.

For your best chance of seeing it, wait until its fully dark outside, and if you can, head to an area with little light pollution.

The Perseid meteor shower is one of the best stargazing events of the year.

At it's peak, the display can produce as many as 150 meteors an hour.

The shower takes place every year as the Earth ploughs through dusty debris left by Comet Swift-Tuttle.

As the particles, ranging in size from a grain of sand to a pea, hit the Earths atmosphere at 60km (37 miles) per second, they burn up and streak across the sky.

The best part about the Perseid meteor shower is that you can see it with the naked eye so there's no need for an expensive telescope or camera to enjoy it.

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To catch a glimpse of Venus, look low in the eastern sky a little before sunrise.

During this time Venus will reach its greatest western elongation of 45.8 degrees from the sun.

This will be the best opportunity to see the planet as it will be at its highest point above the horizon in the morning sky.

During a new moon, the moon and sun have the same elliptical longitude, meaning the lunar disk is not visible from earth.

This month, the phase will occur at 2.42am.

As there is no moonlight interference, this is the best time of the month to observe faint objects such as galaxies and star clusters.

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Top astronomical events to look forward to in August 2020 - Wales Online

Astronomers have found another strange exoplanet in a distant solar system. This ones an oddball because its size is intermediate between Earth and Neptune, yet its 50% more massive than Neptune.

Astronomers have found what they call puff planets in other Solar Systems. Those are planets that are a few times more massive than Earth, but with radii much larger than Neptunes. But this planet is the opposite of that: its much more massive than Neptune, but it also has a much smaller radius. Super-dense, not super-puffy.

This oddball planet is calling into question our understanding of how planets form.

Astronomers with the National Science Foundation NOIRLab studied the planet and presented their findings in a paper titled The Habitable-zone Planet Finder Reveals A High Mass and a Low Obliquity for the Young Neptune K2-25b. Lead author is Gudmundur Stefansson, a postdoctoral fellow at Princeton University. The paper will be published in The Astronomical Journal and is available at arxiv.org.

The Kepler mission found the planet in 2016. It orbits K2-25, an M-dwarf star in the Hyades star cluster. K2-25b orbits its star every 3.5 days. According to this study, it has a mass of about 24.5 Earth masses, and a radius of about 3.4 Earth radii. In the intro to their study, the authors write that These properties are compatible with a rocky core enshrouded by a thin hydrogen-helium atmosphere (5% by mass).

The planet caught the interest of astronomers partly because its a sub-Neptune planet. A sub-Neptune can have either a mass larger than Neptunes along with a smaller radius, like this one, or it can be less massive than Neptune, but with a larger radius. Either way, sub-Neptunes conflict with our models of planet formation. Understanding how these types of planets form is a critical question right now, on the frontier of exoplanet science.

K2-25b is unusual, said lead researcher Gudmundur Stefansson, a postdoctoral fellow at Princeton University. The planet is dense for its size and age, in contrast to other young, sub-Neptune-sized planets that orbit close to their host star, said Stefansson in a press release. Usually these worlds are observed to have low densities and some even have extended evaporating atmospheres. K2-25b, with the measurements in hand, seems to have a dense core, either rocky or water-rich, with a thin envelope.

Astronomical models show that large planets form with a rocky core first. The initial mass for a core is modest, perhaps only 5 to 10 times more massive than the Earth itself. Then gas gathers around the core, creating a gaseous envelope thats hundreds of times more massive than Earth. The gas giant Jupiter likely formed this way.

But a planets like K2-25b seem to show that our understanding is incomplete. It appears to have an enormously massive rocky core, with very little gaseous envelope. Its unusual properties pose a couple questions: How did it end up with such a massive rocky core? And, since it has such a massive core, how come it doesnt have a large gaseous envelope?

While we dont fully understand how K2-25band other planets like itform, this planet is a sort of natural laboratory for studying them. Given its known age and well characterized orbital parameters, the authors write in their paper, K2-25b is a benchmark system to study M-dwarf planet formation and subsequent dynamics, giving us further insights into the formation and migration mechanisms that produce other hot Neptune exoplanets.

Given its large core, it shouldve acquired an enormous gaseous envelope. That fact that it didnt gives rise to several possibilities. One of those possibilities, the authors suggest, is that the rocky core formed through mergers. To explain its currently observed mass, we surmise that K2-25b could be the product of planet merging events of smaller planetary cores to produce a more massive planet.

That explanation also has the added benefit of accounting for the planets orbital eccentricity. They write: Such a dynamical environment could have excited K2-25b into an eccentric orbit, and K2-25b could be in the process of migrating to a shorter period orbit through tidal interactions with the host star.

Discoveries like this one are frequently the result of technological advances. Instruments like SPHERE, on the European Southern Observatorys (ESO) Very Large Telescope (VLT), are responsible for many recent discoveries. But in this case, the piece of technology that made it possible was a $500 off-the-shelf diffuser. Lead researcher Gudmundur Stefansson developed a way of using Engineered Diffusers in his doctoral thesis.

An Engineered Diffuser spreads out the light from a star so that it covers more pixels on the camera. That allows the brightness of the star during the planets transit to be measured more accurately, which results in a higher-precision measurement of the size of the orbiting planet, among other parameters. The innovative diffuser allowed us to better define the shape of the transit and thereby further constrain the size, density and composition of the planet, said Jayadev Rajagopal, an astronomer at NOIRLab who was also involved in the study.

K2-25b is posing some important questions for astronomers. Answers to these questions will have to wait, but maybe not for too long. K2-25b is a prime candidate for follow-up observations with the James Webb Space Telescope. The Webb will have powerful onboard coronagraphs which will block out the light of exo-suns, making it easier to see the orbiting planets. Itll also observe in infrared, something that itll excel at from its position at L2.

The Gemini South Telescopes GHOST (Gemini High Resolution Optical SpecTrograph) also has K2-25b on its list of targets. Its a spectrograph with a wide simultaneous wavelength coverage at high observational efficiency according to the website. Itll be very effective at observing the atmosphere of planets like this one.

More observations with GHOST and the JWST may not answer all the questions that K2-15b poses about planet formation. But they will expand the boundaries of what we do and dont know about it. In the mean-time, maybe more astronomers will come up with low-budget ways of addressing them.

The diffuser that made this study so effective was used with the WIYN 0.9-meter Telescope at Kitt Peak National Observatory (KPNO). The 3.5-meter telescope at Apache Point Observatory (APO) in New Mexico was also part of the study. The National Optical-Infrared Astronomy Research Laboratory(NOIRLab) includes the Gemini Observatory, the Kitt Peak Obsevatory, as well as several other facilities and the upcoming Vera C. Rubin Observatory.

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A Strange Planet has been Found thats Smaller than Neptune But 50% More Massive - Universe Today

Just add starlightWhen contemplating what types of planets might harbor life, scientists first consider their host stars. High-mass stars live fast and die young, blazing with tremendous energy but burning out in just a few million to a few hundred million years. Thats probably not long enough for life to really get going on any orbiting planets.Stars with just a few solar masses or lower produce less radiant energy and thus have smaller habitable zones, defined as the region around a star where a planet can sustain temperatures conducive to hosting liquid water on its surface. But these stars longer lifespans give their planets billions of years for any primitive life to evolve into complex forms. The Sun, for example, has given terrestrial life plenty of time, and life has needed that time to express its full potential. Multicellular life didnt emerge until Earth had been around for roughly 3.5 billion years. And advanced plants and animals didnt arise until Earth was 4 billion years old, after oxygen had built up in the atmosphere. This highly reactive element provided the required energy for more dynamic metabolism. A major question mark centers around the lowest-mass stars, red dwarfs. They comprise three-fourths of our galaxys stars and live for trillions of years. But their feeble energy outputs ensure small habitable zones nestled very close in to the star. This proximity subjects planets to bombardment from powerful flares, which can erode their atmospheres. But red dwarfs calm down over time, potentially giving planets time to regenerate a gaseous envelope. Most of these stars habitable-zone planets are tidally locked, with one side always facing the star and the other in permanent night. But thick greenhouse-gas atmospheres and raging winds could smooth out the hemispheric temperature differences that result from tidal locking.Even the concept of the habitable zone is overly simplistic. As traditionally conceived, the Suns habitable zone currently encompasses Earth and extends to roughly the distance of Mars. And in fact, NASA missions have returned overwhelming evidence that Mars once had rivers, lakes, and oceans of liquid water.

Whether a planet has liquid water on its surface is a function of both surface temperature and atmospheric pressure. For example, water boils on Mars today despite the cold temperatures because of its very low atmospheric pressure. Mars originally had a thicker atmosphere, which allowed it to have liquid water on its surface. But the Red Planet lost most of its atmosphere long ago, partially because it is a low-mass planet. If Mars had higher mass, it could have hung on to its atmosphere for a much longer period of time, perhaps all the way to the present.

That raises intriguing questions about whether planets of certain sizes and masses are best suited for life. Ren Heller of the Max Planck Institute for Solar System Research has argued that Earth is not necessarily the most habitable type of planet. After all, large tracts of Earths surface are nearly devoid of life, such as deserts, the poles, and nutrient-poor oceanic regions. Everybody is crazy about the most Earth-like planet, says Heller. But from a more general, more reflective perspective on the question of life in the universe, I dont see any reason why Earth should be the optimal place for life to form and evolve. There might even exist planets that have more benign environments for life to develop and to diversify.

Read more from the original source:

What planets should we search to find alien life? - Astronomy Magazine

We have four objectives, Ken Williford, Deputy Project Scientist for NASAs Mars 2020 mission, told Astronomy earlier this year. The first three are really our core science objectives. And the fourth is preparing for human exploration.

Perseverances science objects are: seeking out sites that were potentially habitable in the past, looking for signs of ancient microbes within rocks known to preserve life, and collecting and storing promising rock samples for a future return mission.

The rover aims to accomplish these goals using a unique and sophisticated suite of instruments including a rock-blasting laser, microphones and cameras, a powerful coring drill, a mobile weather station, and the first ground-penetrating radar ever sent to Mars surface. Although there are some new additions to Perseverance, many of these high-tech tools are just upgraded versions of what the Curiosity rover carried to the Red Planet in 2012. And thats because NASA is employing what they call the heritage approach for Perseverance, borrowing what worked from Curiosity.

[Perseverance] is something like 90 percent spare parts from Curiosity, Jim Bell, principal investigator for Perseverances Mastcam-Z instrument, told Astronomy earlier this year. Thats how they got the mission approved, because they could save an enormous amount of money by using those spare parts.

But that doesnt mean Perseverance is cheap. Its still about a $2-billion project, and NASA expects to spend up to a total about $2.7 billion over the entirety of the mission.

The rest is here:

Mars 2020 launch: NASA's Perseverance rover ready for the Red Planet - Astronomy Magazine

After the COVID-19 rules about social distancing went into effect, I developed a morning routine of jogging through the woods near my home. During the first months, I focused on the green branches that stretch upward towards the sky, but recently I started to notice the debris of tree trunks lying on the ground. There are many such remnants, eaten by termites, rotting and ultimately dispersing into the underlying soil. A glimpse at the forest reveals a sequence of evolutionary phases in the history of trees that lived or died at different times.

The phenomenon happens in other contexts. For example, I recently completed a nine-year term as chair of the Astronomy Department at Harvard. And only now have I begun to notice the former chairs scattered around me, just like those tree trunks in the woods.

Entering a new stage of life can be humbling. We acquire a false sense of permanence from reviewing the frozen past, as if it were a statue that will never erode. But this view is shortsighted, since each moment can also be seen a new beginning, shaped by forces beyond our control and swirling on a grander scale.

Old-fashioned astronomy was also permeated by a false sense of permanence. Astronomers collected still images of the universe, creating the impression that nothing really changes under the sunor above it, either. But just like the revelation from my stroll through the woods, these snapshots showed stars and galaxies of different ages, at various evolutionary phases along their history. Computer simulations helped us patch together the full story by solving the equations of motion for matter, starting from the initial conditions imprinted on the cosmic microwave background at early cosmic times. By generating snapshots of an artificial cosmos similar to those captured by telescopes, these simulations unraveled our cosmic roots. The scientific insight that emerged is that the likely origins for our existence were quantum fluctuations in the early universe. Perhaps we should add Quantum Mechanics Day to our annual celebrations of Mothers Day and Fathers Day.

There are some missing pages in the photo album made up of our observations, however: the period known as the cosmic dawn, for example, when the first stars and galaxies turned on. These missing pages will be filled in the coming decade by the next generation of telescopes, such as the James Webb Space Telescope (JWST), the ground-based "extremely large" telescopes and the Hydrogen Epoch of Reionization Array (HERA).

To reveal a more literal gap in the sky, the Event Horizon Telescope recently captured a still image of the silhouette of the black hole in the giant galaxy M87. The next goal is to obtain a sequence of images or a video, showing the time variability of the accretion flow around the black hole.

The tradition of still images makes sense when dealing with systems like galaxies, which evolve on a timescale of billions of years. But the universe also exhibits transient fireworks that flare up and dim during a human lifetime. Observing them is the motivation behind the Legacy Survey of Space and Time (LSST) on the Vera C. Rubin Observatory, which will have its first light soon. LSST will be a filming project, documenting nearly a thousand deep multicolor images per patch of the southern sky over a decade and recording the most extensive video of the universe ever taken with its plethora of transients in full glory.

Some of the LSST flares are expected to be the counterparts of gravitational wave sources detected by LIGO/Virgo or LISA. Their discovery will usher in multi-messenger astronomy based on both gravitational and electromagnetic waves emitted by the same sources, providing new insights about the central engines that power these transients. The related standard sirens could serve as new rulers for measuring precise distances in cosmology.

Within the Milky Way, transient events close to Earth could lead to catastrophe. A supernova explosion, for example, could cause a mass extinction on an unprecedented scale. If a meteor similar to the one that hit the unpopulated regions near Chelyabinsk in 2013 or Tunguska in 1908 hit New York City, it could cause a far larger death toll and economic damage than COVID-19. Or consider the impact of a blob of hot gas from the Sun, a so-called coronal mass ejection of the type that missed the Earth in 2012. Such an event could shut off communication systems, disable satellites and damage power grids. Altogether, astronomical alerts about such celestial threats could be crucial for securing the longevity of our species.

Of greatest relevance for our long-term survival is identifying large objects on a collision course with the Earth, similar to the Chicxulub asteroid that killed the dinosaurs 66 million years ago. In 2005, Congress passed a bill requiring NASA to find and track at least 90 percent of all near-Earth objects larger than 140 meters (enough to cause regional devastation) by 2020. Only a third of these objects have been identified in the sky so far. In a recent paper with my undergraduate student Amir Siraj, we explained some puzzling properties of the Chicxulub asteroid as a tidal breakup of a long-period comet that passed close to the sun. If future sky surveys alert us to another fragment whose apparent size grows rapidly against the sky, wed better have a contingency plan to deflect its trajectoryor else immediately call our realtor.

Keeping up with the challenge of precision cosmology for the next few decades can demonstrate that the Hubble constant, which describes the expansion rate of the universe, is not really a constant, in accordance with the expected Sandage-Loeb test. In the long run, the only thing that stays constant is change. The accelerated expansion of the universe under the influence of so-called dark energy will be the ultimate manifestation of extragalactic social distancing in the post-COVID-19 era, preventing any future contact between us and civilizations outside our galaxy.

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A Movie of the Evolving Universe Is Potentially Scary - Scientific American

Imagine a planet about 2.5 times the radius of Earth orbiting a distant star. Do you picture something like our own rocky, ocean-strewn world? Or is it something more akin to a small version of a gassy planet like Neptune? Now, two new papers suggest that there may be a third option were not taking seriously enough.

As more and more confirmed exoplanets roll in, one thing is clear: The Sun is not orbited by every type of planet that exists. Our solar system basically has two flavors of planet rocky and gassy. The inner planets make up the former group, and the outer planets make up the latter. But in recent decades, astronomers are finding a lot of worlds that break that familiar mold.

Astronomers general consider super-Earths to be exoplanets that have up to about four times the mass of Earth and a radius up to about 1.6 times that of Earth. But because theres been such a wide variety of planets found around other stars, the exact definition of a super-Earth is still largely debated.

To muddy things further, mini-Neptunes are what astronomers usually call planets that have masses several to 10 or more times that of Earth (Neptune is about 17 times the mass of Earth), plus a radius more than 1.6 times that of Earth. The assumption was that even the smallest of these mini-Neptunes are too girthy to be rocky worlds, so they were thought to be made of mostly hydrogen and helium, like a normal gas giant.

In the community, there was this stance that we were really looking at two populations [super-Earths and mini-Neptunes], Jrmy Leconte, an astrophysicists at the French National Centre for Scientific Research (CNRS) and coauthor of a new paper on the topic, tells Astronomy. But without an easy way to directly capture images of either type of planet, the exact dividing line remained fuzzy.

Now, based on Lecontes and others recent work, its starting to look like super-Earths and small mini-Neptunes might be two versions of nearly the same thing.

On June 15, scientists at the Laboratoire d'Astrophysique de Marseille published a paper in The Astrophysics Journal Letters that suggests mini-Neptunes dont have to rely on hydrogen and helium for their fluffy compositions. Instead, the study claims, mini-Neptunes could be irradiated ocean worlds with dense, rocky cores and ultrathick atmospheres of water.

Such an atmosphere, the researchers says, could be the result of an intense greenhouse effect caused by the rocky planets fiery host star boiling water from its surface. Such a scenario, the study suggests, could keep the planets mass in check, while also greatly increasing its radius.

Furthermore, Lecontes recent work, published June 9 in Astronomy & Astrophysics, focuses on how host stars can irradiate the surfaces of a rocky, water-rich exoplanets. This process, the research suggests, can indeed create an expansive atmosphere that balloons a solid rocky world into what looks like a shrunken gas giant.

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Mini-Neptunes could be super-Earths with bloated atmospheres of water - Astronomy Magazine