Category Archives: Astronomy

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. 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.

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

High on Cerro Tololo mountain in northern Chile stands the Inter-American Observatory. It is one of a growing number of astronomical observatories in the dry and clean air of the Andes mountains.

Telescopes have been increasingly located in Chile because many other sites in the world have slowly been compromised by air and light pollution or politics like that which stopped the worlds biggest telescope planned for Mauna Kea in Hawaii.

Even in Chile, all is not well. Light from distant Chilean cities could threaten Cerro Tololo mountain where more than 20 telescopes now operate.

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Larger telescopes than those on Cerro Tololo already exist in Chile and other high mountains of the world. Such giant telescopes now cost more than a billion dollars each. Because of the high demand for their use and the need to recover costs, observation time on them is often very expensive. Astronomers can wait years for an open slot to make images for their project. Strangely then, it might be soon that the observatory site will no longer matter.

Think of this. How would researchers feel if their photos taken through a major telescope were vandalized by someone who drew bright streaks across them. No matter what telescope they used, no matter where on Earth, similar streaks would show up.

Unfortunately, we dont have to imagine this because just such a vandal has shown up, and he will continue unless we stop him. Elon Musks SpaceX corporation just ruined photos taken at the Inter-American Observatory. The wrecked images are part of a big project to survey the entire southern sky to look for dark matter in galaxies.

The angry astronomers have posted their photos on the internet for us to see. They are marred by multiple dotted tracks caused by SpaceXs latest batch of 60 Starlink satellites that were launched on Nov. 11. These 60 large satellites are the second batch of 60 on the way to as many as 42,000 of them! The Federal Communications Commission (FCC) has already approved launch of 10,000.

The satellites are startlingly bright in the night sky, although they will soon climb to a higher orbit where it is claimed they will be just barely visible. While such satellites might not ruin the night sky for casual observers such as you and me with our naked eyes, they will still be ruinously bright in the giant telescopes that are so sensitive to light that they can pick up the equivalent of a candle 500 miles distant.

In a very modest gesture toward astronomy, Musk says the satellites will have their earthward-facing sides painted black, although this hasnt happened so far. It hardly matters because they will make just as big a photographic streak if painted black, and they will thoroughly disrupt radio astronomy, too.

Last spring, Musk said that as with the Hubble Space Telescope, astronomy as a whole needs to move its telescopes into space. That has already happened to a small degree, but there are no plans to move all instruments there even if it was possible. Almost all are far too large to move and/or to deploy in space. Billions of dollars and generations of work will become stranded assets, not to mention thousands of careers of astronomers, their support and thousands more in related disciplines and businesses. In addition, space, especially low orbit space, is not as safe as it might appear (more on this later).

SpaceX is not the only company with plans like this. Amazon and OneWeb have announced their intention to deploy their own giant internet webs. No doubt more entities are hatching similar plans.

Just as important as the future of Earth bound astronomy is the fate of low Earth orbit space. This is extremely valuable territory, and it is owned by no one. It is a commons. Like so many commons, it is being filled to the brim with no overall plan or limit.

The 1960s saw the first artificial Earth satellites. Since then, about 8,700 of them have been launched into orbit. About 4,700 are still up there. That means 4,000 have decayed, most burning up in uncontrolled atmospheric reentries. Taking in account the recent 120 SpaceX satellites launched by just two SpaceX rockets, there are about 1,900 functioning satellites in orbit now. Only a few of these can be deliberately deorbited. SpaceX claims its Starlink satellites will all be capable of planned deorbit. If any fail to orbit correctly or die there, they will be brought down, they say. Space junk, is something they are not intended to become.

Its too bad, but we already have a terrible space junk problem. Its not just the once useful, but now dead satellites whizzing around the Earth. On top of the operational satellites, and pieces of them that have found their way into space, there are the upper stages of used launch vehicles. These are spent rockets that got hung up in orbit once their fuel was expended. Nowadays, these are launched in a way that they will come down, but a number of early day empty rockets remain. These are big pieces of junk. Gases and fuel that came out near the end of the flight also remain in orbit as junk.

Last of all, paint chips come off of dead (and active) satellites and used rockets. These bits are extremely abundant. There are probably millions of chips in orbit. While the thousands of large pieces of space junk are meticulously tracked, its impossible to track the paint chips and other tiny pieces of junk that nonetheless travel in orbits going from 17 to 22,000 mph. This is about 11 to 15 times the speed of a typical rifle bullet.

So far, there has been one satellite collision. There will be more. The end result is many more pieces of junk than the original two satellites.

In 2009, an Iridium 33 and a Kosmos-2251, a commercial and a military satellite, smashed up 490 miles over Siberia at a combined speed of over 26,000 mph. The two objects suddenly exploded in more than a thousand pieces over 4 inches long.

About 70 percent of these pieces of debris are still in orbit.

In 2011, a chunk of the Kosmos-2251 threatened to hit the International Space Station (ISS) but the station was maneuvered out of the way. The chunk missed the ISS with a crew of six by just 130 yards.

A more recent shocker was a near smackup just this September between one of Space Xs Starlink satellites and the European Space Agencys (ESA) large Aeolus satellite. Ahead of time, both the ESA and SpaceX were notified of a possible collision. The ESA responded by increasing the Aeolus altitude. SpaceX missed the message. Later, they said there was a bug in their on-call paging system. The SpaceX satellite was one launched to see how well a deorbiting test went quite an irony.

A large collision does produce very many pieces. Some of these will cause further collisions and even more pieces. Such an event could set in process what is called the Kessler Syndrome.

This refers to a cascade of collisions when there is enough space debris in a low Earth orbit that a collision there would cause a cascade where each collision produces enough new space debris that further collisions will happen until that area of orbital space becomes unusable. That might even make it so that rockets could not fly through the debris cloud to reach high safer orbits.

Natural clearance (deorbiting) of such debris could take a century. Pollution of higher orbits would for practical purposes be permanent.

The movie, Gravity, staring Sandra Bullock and George Clooney was about this.

It would end all the space programs, and what would happen to our economy with its many critical devices that now use satellites?

There are few rules that govern the launch, use and abandonment of artificial satellites except for an old military satellite treaty. It used to be that launching a satellite was expensive. Now at least 60 of them can go up at once; and small organizations, even elementary school classes, can have their own classroom satellite launched. Worse though, in my opinion, SpaceX is acting just like the bandits of old.

At this point, I cant see much beyond adverse public opinion to stop their private grabbing and pollution of near Earth space and destruction of astronomy. These actions will only encourage similar ones by other corporations, organizations, and countries. Another tragedy of the commons is at hand. As usual, the public interest is far behind.

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Destruction of astronomy and the economy - Idaho State Journal

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

S&T Associate Editor Sean Walker gives a rundown of last week's astro-imaging conference.

Astrophotography enthusiasts gathered at the San Jose Convention Center in California for the biennial Advanced Imaging Conference (AIC), which ran from November 15th through the 17th. The event, sponsored by various companies and groups involved with amateur and professional astronomy, featured presentations on all aspects of astrophotography from some of the most well-known imagers from around the globe.

With a record attendance of nearly 500, the show featured something for virtually every aspect of astro-imaging, ranging from techniques to improve data collection to processing demonstrations using popular software packages. Luminaries including Rogelio Bernal Andreo, Adam Block, Ron Brecher, and Kerry-Ann Lecky Hepburn demonstrated some of the work that goes into their eye-catching imagery. While I tried to attend as many talks as I could, three or four were often occurring simultaneously. Fortunately, most presenters gave repeat performances, so attendees had a chance to see everything.

Stephen Bisque readies Software Bisque's new Paramount Apollo Direct Drive Mount.

The AIC also hosts a large showroom floor with manufacturers displaying the latest in robotic telescope mounts, astrographs, and astro-cameras of all makes and models.

The talk of the town this year revolved around the impending end of CCD manufacturing, as well as the maturing state of CMOS technology. Many manufacturers on hand acknowledged the challenges posed by this development, which was not completely unexpected. They have been preparing for it for some time.

In fact, several new astronomical cameras from Atik Cameras, Diffraction Limited, Finger Lakes Instrumentation, and QHYCCD shown this weekend incorporate the latest CMOS sensors. Several new innovations debuted at the show, including a host of new gear from Software Bisque, including the Paramount Apollo Direct Drive mount, and TheSky Fusion integrated control system. Other neat gadgets that caught my eye included a new spectrograph from Starlight Xpress and the Stellina "observation station" (look for our review in the March 2020 issue).

Keynote speaker Professor Ann Zabludoff (University of Arizona), encouraged attendees to get involved with an upcoming program to work with professional observatories to rapidly discover the optical counterparts of gravitational wave events. A quick response to an alert is crucial to understanding the physics behind the progenitors of gravitational waves, and her group is hoping to enlist interested advanced imagers worldwide.

Organizer Ken Crawford presents R. Jay Gabany with the Hubble Award.

The organizers of AIC presented their Hubble Award for significant contribution to the astrophotography community this year to past president R. Jay GaBany for his image-processing innovations and his ongoing pro/am work. GaBany was instrumental in the discovery of galactic star-streams produced when a galaxy cannibalizes its smaller satellites.

Attendee Arora Deepanshu was the lucky winner of the door prize, an L-350 Direct Drive Mount provided by event sponsor PlaneWave Instruments.

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Report from the 2019 Advanced Imaging Conference - Sky & Telescope

There's a chance a rare meteor "storm" will occur Thursday night, and eastern Canada might be able to catch it.

Meteor storms can be defined as a substantially higher-than-normal outbursts of meteors entering our atmosphere, and occur when Earth sweeps through a dense cloud of leftover cometary debris.

These events can produce several hundred meteors per hour. In 1833, a storm associated with the Leonid meteor shower produced 13,000 meteors per hour at its peak.

While the annual alphaMonocerotids is forecast to produce an outburst this year, it is not expected to be anywhere close to that rare 1833 event. But it will still be something to see if the weather co-operates.

"We might see a meteor, and then a few seconds another meteor, and then two more meteors,"said Peter Brown, professor and Canada research chair at Western University's department of physics and astronomy.

However, there are a few things that make this potential outburst unpredictable, particularly for us here in Canada.

One is that the radiant, or the area from which the meteors appear to originate the constellation Monoceros, which is where the shower gets its name will be low in the south, to the lower left of the very familiar constellation Orion.

The other is that, unlike with many meteor showers, it's not known whichcomet is responsible for this one,which makes it more difficult to understand where much of the debris is and how spread out it is.

As well, there's the good old Canadian fall weather: it's typically cloudy this time of year.

And finally, it's how brief the shower will be: the peak is between just 15 and 20 minutes.

"Hollywood always has this view of meteor showers as these things that happen in 20 minutesand it's all over," Brown said. "And every other meteor shower is not like that except this one and that's rare."

The potential storm is making headlines due to the prediction by astronomers and meteor expertsPeter Jenniskens and Esko Lyytinen,recently published on the site Meteor News, thatthere's the potential for this year's shower to produce between 100 meteors an hour and upwards of 1,000 an hour.

To put that in perspective, two of the year's best meteor showers the Perseids in August and the Geminids in December can produce, at their peak, about 100 to 150 meteors per hour in a dark-sky location.

The alpha Monocerotids, however, which occur at this time of year, typically only produce just a few an hour.

The last outburst, in 1995, produced roughly 400 an hour.

Jenniskens and Lyytinen made the forecast for the burstbecause the geometry the location of Earth, the location of the debris field is believed to beroughly the same as it was in 1995.

However, because there are a lot of unknowns, some astronomers believe the outburst will produce far fewerthantheir prediction.

"This year is the best geometry encounter since 1995," Brown said."The problem is the exact encounter geometry depends on really knowing the orbit of the meteoroidsas well, and we don't know them that precisely. So within that uncertainty, it could be that we just glance the trail or miss it in which case nothing happens towe plow right through the middle."

If Earth does plow right through it, that means we'll get an intense shower for 15 or 20 minutes, perhaps seeing five or six meteors every minute.

"Even if everything works out well, you'd see in 30 minutes to 40 minutes as many meteors as you'd see during the peak of the Perseids when the radiant is right overhead," Brown said. "It'll be obvious that something is going on."

But even in the best-case scenario, with aperfectly clear sky, there's still that narrow window.

And even then, the entire country won't be privy to the show.

Anyone west of roughly Saskatoonwon't be able to see it.

The peak will begin at roughly 4:50 a.m. UTCFriday, whichwill be:11:50 p.m. Eastern Time and 10:50 p.m. Central Time on Thursday; and12:50 a.m. Atlanticand 1:20 a.m. Newfoundland Time on Friday.

If you're clouded out, you can always try watching online (providing there areclear skies). The Virtual Telescope Project will attempt to catch the outburst and cover it live.

If we do indeed see any, these meteors are fast-moving, andthere could be "grazers" meteors that come in at a shallow angle. These meteors are going through more atmosphere, producing long tails before finally burning up entirely.

Whether or not it puts on a show, astronomers will be able to learn more about this strange annual meteor shower.

It wasn't until the 1950s that astronomers began to realize this was an annual meteor shower. Andit wasn't until 1995 that it became clear the comet responsible was unknown, and highly unusual in its orbit.

But for the general public, it's yet another reminder that there's a lot going on in our solar system and that it's not always so predictable.

"It's neat. I think people should go out and take a look," Brown said. "You never know."

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Astronomers believe we could be in for a rare meteor storm - CBC.ca

The researchers created simulations to show that this was possible and described their results in the journal Physical Review Letters.

On July 29, 2017, gravitational wave detectors spotted the heaviest black hole merger yet, dubbed GW170729. One of the black holes in the merger was likely more than 50 times the mass of the Sun. Black holes that are created when a dying star collapses shouldnt be this big, so astronomers think something else was probably at play. Maybe that black hole was the result of a previous merger itself.

One place where a black hole might swallow multiple other singularities is in an environment thats dense with stars. Globular star clusters, for example, pack lots of stars and the black holes they sometimes form into a relatively tight space. There, a black hole might meet and combine with other black holes multiple times.

The new paper describes another kind of environment where black holes might merge more than once. Disks of material that swirl around supermassive black holes, the papers authors propose, might shepherd smaller black holes within them into similar tracks. As in the star clusters, there black holes might eventually converge on multiple occasions.

The researchers created simulations of these orbiting black holes and found that a series of mergers would create black holes that are 50 or more solar masses, like the more massive black hole in the merger GW170729.

The mergers from black holes orbiting a supermassive black hole would probably have rotation characteristics distinct from other merger scenarios. As gravitational wave detectors spot more black hole mergers, their data might be a way to tell whether these oddly large black holes are really createdthis way.

So far, scientists have identified 10 confirmed mergers of black hole pairs. But there have been many more gravitational wave detections that are black hole merger candidates, which scientists are working to confirm.

Whatever questions were asking, were going to have a much, much better handle on answering them within a very short time period, said Imre Bartos, an astronomer at the University of Florida, Gainesville, and one of the authors of the new paper. Its super exciting.

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Huge black holes might have merging baby black holes around them - Astronomy Magazine

Observing the transit of an inner planet requires a telescope with a solar filter that allows viewing the sun without eye damage. The transit appears as a small black dot that slowly moves across the face of the sun. It isnt visible without magnifying the suns image.

The transit of Mercury is a bit like what happens in a solar eclipse. Instead of the moon coming between Earth and the sun, which can entirely block the suns light, Mercury is much farther away, so it blocks only a small fraction (less than half a percent) of the sun. But even though its only a small black dot, its clearly visible with the right telescope.

The historical importance of the transit of Mercury goes back to the 1600s, when Johannes Kepler, famous for his planetary orbital laws, was the first astronomer to predict it. Back then, there was still public controversy about the model of Copernicus, where planets go around the sun, and the older view that the sun orbited Earth. The transit of Mercury was first observed in 1631 by French astronomer Pierre Gassendi, and was irrefutable evidence that Copernicus was right.

In 1677, Edmund Halley, for whom Halleys comet is named, realized that he could use the transit of Mercury to find the distance to the sun. He did that by measuring the time of the start and finish of Mercurys shadow as it went across the sun, and then used the mathematical technique of parallax to calculate the distance. This was a tour-de-force calculation for its time.

Today, the transit of Mercury is more of a curiosity than a groundbreaking scientific event. However, an interesting application of this technique has been applied to look for planets around other stars. The NASA space telescope Kepler made very careful measurements of the brightness of stars, and found periodic times when the brightness dipped by about 1%. Thats expected to happen when an exoplanet orbits the star and comes between that star and the view from Earth. Thousands of exoplanets have been discovered using the method.

The transit of planets can be used as a great teaching moment for amateur astronomers, either young or old. Its one thing to learn about the planetary orbits in a textbook, but another entirely to see a planets shadow move across the sun in real time.

Kenneth Hicks is a professor of physics and astronomy at Ohio University in Athens.

hicks@ohio.edu

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Astronomy: There are lessons to be learned from transit of Mercury across sun - The Columbus Dispatch

Innermost planet Mercury puts on its best morning display of the year for Northern Hemisphere observers from late November to early December. Skywatchers in the British Isles should find a location offering an unobstructed view of the southeast horizon about 45minutes before sunrise to get the best views. This looping animation shows the changing configuration of Mercury, Mars and Virgos brightest star, Spica, from 18November through 3December at dawn. Note the span of a fist at arms length (about 10) for scale, but the Moons apparent size on 24 and 25November has been enlarged for clarity. AN animation by Ade Ashford.Mercurys transit of the Sun on 11November is still fresh in the memory, but it doesnt take long for the innermost planets orbital motion to carry it far enough west of the Sun to be visible low above the southeastern horizon in dawn twilight. Mercury attains its greatest westerly elongation of 20degrees on the UK morning of 28November. In fact, for Northern Hemisphere observers, the remainder of the month into early December offers Mercurys best morning viewing prospects for the entire year.

Any opportunity to get a glimpse of this elusive and fast-moving planet is well worth getting up a little earlier for, particularly when as now you get a chance to see Mars nearby at the same time. As with any observation made in the eastern sky during dawn twilight, timing is everything: you need to view late enough that Mercury gets a chance to rise high enough above the horizon murk, but not so late that impending sunrise makes the sky too bright to see it. (Never look anywhere near the Sun after it has risen.)

Observers in the British Isles need to find a location that offers an unobscured view of the southeast horizon about three-quarters of an hour before sunrise between now and the first week of December. Our interactive online Almanac gives you the time of sunrise for your nearest town or city, so just subtract 45minutes from that.The slim crescent of the 27-day-old waning Moon lies slightly less than 4degrees above magnitude +1.7 Mars at UK dawn on Sunday, 24November 2019, hence the pair will fit in the same field of view of 10 and lower magnification binoculars. On this morning, the Red Planet sits midway between magnitude -0.2 Mercury and first-magnitude star Spica in Virgo. Note that the Moons apparent size has been enlarged for clarity in this illustration. AN graphic by Ade Ashford.Mercury is located in the constellation of Libra for the period illustrated in the animation at the top of the page. The planet lies about 9degrees (almost the span of a fist held at arms length) above the southeast horizon at the optimal viewing time between 23November and the beginning of December. The Red Planet sits midway between Mercury and the first-magnitude star Spica, the brightest in the constellation of Virgo, at UK dawn on 24November.

Magnitude +1.7 Mars remains in Virgo until the morning of 1December when it crosses the constellation border to join Mercury in Libra. Mercury brightens more than fourfold from magnitude +1 to -0.6 during the 18November to 3December observing window. If clear, dont miss the binocular highlights of 24 and 25November at dawn when the old waning crescent Moon lies 4 above Mars and 3 to the lower left of Mercury, respectively.

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See Mercury at its best meet Mars in the dawn sky - Astronomy Now Online

The Institute for Astronomy helped people gathered at Waialae Beach Park to observe the event. PC: University of Hawaii

The planet Mercury did its best Icarus impression last week, and students from the University of Hawai traveled to the Big Island for a chance to witness it.

University of Hawaii astronomers joined many observers around the world in tracking the transit of Mercury on Monday, Nov. 11. A transit is when a planet passes in front of a star. Mercury and Venus are the only two planets that can be observed from Earth in transit.

About 30 UH Mnoa students flew to Hawaii Island to view the event at the Subaru Telescope as part of a group of around 200 people to use solar telescopes.

UH Mnoas Institute for Astronomy held a viewing party at Waialae Beach Park for more than 100 people.

Mercury takes just 88 days to circle the Sun. It passes between the Sun and Earth frequently but usually out of view.

The transit of Mercury will not be seen from Earth again until November 2032, and not from Hawaii until 2049. The next transit of Venus will not be visible from Earth until 2117.

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Astronomy in Transit - Big Island Now