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This Week’s Sky at a Glance, February 5 – 13

Fri, 02/05/2016 - 11:42
Moon, Venus, Mercury in early dawn, Feb. 4-6, 2016

The only sizable objects that are closer to the Sun than the Earth is are Venus, Mercury, and (at this time of the lunar month) the Moon. See all three grouped low in the southeast in early dawn of Saturday the 6th.

Friday, February 5

• You can still see all five naked-eye planets at dawn, though Mercury is getting lower. On Saturday morning the 6th, the crescent Moon, Venus, and Mercury form a triangle low in the southeast, as shown here. See Bob King's article It's Not Over Till the Fast Planet Sinks.

Saturday, February 6

• Bright Capella high overhead, and equally bright Rigel in Orion’s foot, are at almost the same right ascension. This means they cross your sky’s north-south meridian at almost the same time (around 8 p.m. now, depending on how far east or west you live in your time zone). So whenever Capella passes its very highest overhead, Rigel marks true south over your landscape. And vice versa.

Sunday, February 7

• After nightfall, the Pleiades pose very high in the southwest with the Hyades and Aldebaran to their left. Nearly twice that far below the Pleiades glimmers one lone, modestly bright star: Menkar, or Alpha Ceti, in the head of dim Cetus the Whale. Can you see its orange tint?

Monday, February 8

• Look due east after dark, fairly low, for twinkly Regulus. Extending upper left from it is the Sickle of Leo, a backward question mark. "Leo announces spring," goes an old saying. Actually, Leo showing up in the evening announces the cold, messy back end of winter. Come spring, Leo will already be high.

• New Moon (exact at 9:39 a.m. EST).

Tuesday, February 9

• With the Moon new and Orion high, explore the rabbity telescopic sights of Lepus, the Hare under Orion's feet, using Sue French's Deep-Sky Wonders article, chart and photos in the February Sky & Telescope, page 50. Get to know winter's only globular cluster. And what about that sextuple star known as NGC 2017?

Wednesday, February 10

• By 9 or 9:30 the Big Dipper stands on its handle in the northeast. In the northwest Cassiopeia also stands on end, at about the same height.

Thursday, February 11

Look west-southwest at nightfall for the thin crescent Moon. High above it, by some 30°, are the two brightest stars of Aries pointing down to it. Above or upper left from there you'll find the Pleiades.

• It's a busy night around Jupiter. Europa's shadow crosses the planet's face from 9:02 to 11:51 p.m. EST, followed by Europa itself from 10:15 p.m. to 1:00 a.m. EST. Meanwhile Io's shadow moves onto Jupiter starting at 12:51 a.m. EST. Subtract 3 hours from these to get Pacific Standard Time.

Friday, February 12

• The sky's biggest asterism (informal star pattern) is the Winter Hexagon. It fills the heavens toward the east and south these evenings. Start with brilliant Sirius at its bottom. Going clockwise from there, march through Procyon, Pollux and Castor, Beta Aurigae and Capella near the zenith, Aldebaran over and down to Capella's lower right, down to Rigel in Orion's foot, and back to Sirius.

Saturday, February 13

• Orion is now high in the south-southeast right after dark. Left of it is Gemini, headed up by Castor and Pollux at far left. The stick-figure Twins are still lying on their sides. Well below their legs is bright Procyon in little Canis Minor, the doglet whose top is barely seen in profile (in a dark sky). He's currently vertical. Procyon marks his rump.


Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy.

Pocket Sky Atlas, jumbo edition

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but it's less than one per square degree on the sky. Also plotted are many hundreds of telescopic galaxies, star clusters, and nebulae. Shown is the new Jumbo Edition for easier reading in the night. Click image for larger view.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The basic standard is the Pocket Sky Atlas (in either the original or new Jumbo Edition), which shows stars to magnitude 7.6.

Next up is the larger and deeper Sky Atlas 2000.0, plotting stars to magnitude 8.5, nearly three times as many. Next up, once you know your way around, is the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, or the bigger Night Sky Observer's Guide by Kepple and Sanner.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (meaning heavy and expensive). As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."

This Week's Planet Roundup Jupiter with very red Great Red Spot on Jan. 12, 2016

Just how red can the Red Spot get? We may be finding out. Jupiter's Great Red Spot is at least as strongly colored this season as it has been in living memory. It's pretty easy in a 3-inch scope when its side of Jupiter faces Earth. Christopher Go in the Philippines took this stacked-video image with a 14-inch scope on January 12th.

Mercury (magnitude –0.1) is sinking a little lower in the southeast before dawn. But you can still spot it 4° or 5° lower left of brilliant Venus.

Venus (magnitude –3.9) is also gradually getting lower in the southeast during dawn.

Mars (magnitude +0.7, in the center of Libra), rises around 1 a.m. and glows yellow-orange in the south as dawn begins. In a telescope it's still a small 7 arcseconds in diameter. Notice its gibbous shape; Mars is at western quadrature this week (90° west of the Sun). Mars will appear more than twice as large, 18.6 arcseconds in diameter, when closest to Earth in late May and early June.

Jupiter (magnitude –2.4, between Leo and Virgo) rises in the east around 8 p.m. and shines highest in the south around 2 a.m. By dawn it's getting low in the west-southwest.

Saturn (magnitude +0.5, in southern Ophiuchus) rises around 3 a.m. and is fairly well up in the south-southeast by the beginning of dawn. Spot Antares 7° to its lower right. Mars glows three times as far to Saturn's right or upper right. In a telescope, Saturn's rings are tilted a wide-open 26° from edgewise.

Uranus (magnitude +5.9, in Pisces) is still in the west right after dark. Finder chart.

Neptune (magnitude +8.0, in Aquarius) is getting lost in the sunset.

Planet Nine (probably fainter than magnitude 22, and probably not in the zodiac) seems reasonably likely to be out there, but it could be anywhere along a wide sheaf of orbits inclined roughly 30° to the ecliptic. And it's most likely to be near its aphelion, hundreds or even 1,000 a.u. away.


All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Standard Time (EST) is Universal Time (UT, UTC, or GMT) minus 5 hours.


“This adventure is made possible by generations of searchers strictly adhering to a simple set of rules. Test ideas by experiments and observations. Build on those ideas that pass the test. Reject the ones that fail. Follow the evidence wherever it leads, and question everything. Accept these terms, and the cosmos is yours.”

— Neil deGrasse Tyson


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Categories: Astronomy Headlines

Stars Form in Turbulent Times

Fri, 02/05/2016 - 10:05

New images of four disks around forming stars known as protostars suggest that the star formation process is much more violent than previously thought.

A Gravitationally Unstable Circumstellar Disk (Model)

A model shows what a violent circumstellar disk should look like.
Hauyu Baobab Liu et al.

A star’s birth is somewhat of a mystery. Because they form behind an enormous veil of dusty — and often beautiful — molecular clouds, nature blocks the details from view. But astronomers think that within these clouds, small pockets of gas begin to collapse under their own gravity into protostars, fed steadily by spinning gaseous disks.

A new study, however, published February 5th in Science Advances suggests that this slow and steady accretion might not win the race after all. It’s more likely that matter in the circumstellar disk piles up and then dumps onto the protostar in episodic bursts.

See, there’s always been a problem with the previous theory: when astronomers actually observe these protostars in action, they appear far too faint. In other words, far too little matter is accreting onto these protostars at any given time — there’s simply no way a protostar could become a full-fledged star in just a few million years at such low luminosities. At least not if the process is slow and steady.

At the same time, a handful of protostars are known to brighten by a factor of more than 100 in just a matter of decades before they settle back down. Looking at these clues side by side, astronomers drew the obvious conclusion: the protostars are growing in violent fits and bursts. Because these episodes of intense accretion don’t happen often, astronomers are less likely to see the stars-to-be in the bright phase.

“It’s like stars form when you’re not looking,” says Michael Dunham (Harvard-Smithsonian Center for Astrophysics).

But observers have been unable to provide direct evidence of episodic accretion, and theorists don’t like the extra mess it adds to their models. So Hauyu Baobab Liu (Academia Sinica Institute of Astronomy and Astrophysics, Taiwan), Dunham, and their colleagues decided to take a closer look at the circling disks around four extremely bright protostars. They were looking for the smoking gun of episodic accretion: gravitational instabilities in the disk should lead to visible pile-ups such as clumps and streamers.

Seeing circumstellar disks in such detail is no easy task. First the team had to use adaptive optics to overcome the Earth’s atmosphere, which blurs details. Then the team had to block out the protostar’s light with a coronagraph in order to see the faint disk. Finally, the team used a technique called polarization differential imaging, which compares two images of the light scattered from different directions to better see surface features. Dunham says this technique can be used to take a picture of a mountain range through a thick fog.

Oh and they observed these disks on the Subaru telescope on Mauna Kea, one of the largest telescopes in the world. At the end of the day, their diligence was worth it. “I’ve never seen anything like this in terms of the observations,” says Chadwick Young (Nicholls State University), who was not involved in the study.

Circumstellar Disks of Young Protostars

The images above show clear streams, arcs and clumps within four protoplanetary disks, suggesting stars form after a rough and bumpy ride.
Hauyu Baobab Liu et al.

All four images show arms, arcs, or streams. Although it’s what the team had hoped for, Dunham was surprised that the images were so spectacular. “There are these arc-like features. There’s even one case where there's the streamer coming out of the disk … And that's exactly what the models and the computer simulations of this process predicted.”

Another expert is still holding out for more: “It's one more important bit of evidence that the picture holds together,” says Neal Evans (University of Texas), who was not involved in the study. Next, he’d like to see the team observe at another wavelength. The scattered near-infrared light the astronomers imaged only probes the disk’s surface. But at a different wavelength, say radio waves, the team could actually peer inside these dusty features and verify that they persist throughout the disk.

Lucky for Evans, the team plans to do just that. In addition, Dunham says the team would like to observe the bright protostars’ fainter counterparts. If episodic accretion is going to happen anytime soon — at least within the next several hundred thousand years — then the team should be able to see arms and streams as they’re forming. It would be final proof that all protostars form during turbulent times.


Hauyu Baobab Liu et al. “Circumstellar Disks of the Most Vigorously Accreting Young Stars.”Science Advances. February 5, 2016.

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AAS Adopts Worldwide Telescope

Fri, 02/05/2016 - 09:59

The largest national association of astronomers is now the new home of a virtual observatory known as the WorldWide Telescope.

AAS and WWT Logos

American Astronomical Society

Imagine a future where astronomy research comes to life. Rather than read a dry paper abstract, researchers will soon watch the paper’s author show and explain the observations. Scrolling through an article on, say, star formation, researchers can click on the images within and explore the actual regions where stars are born.

That future is now, and that’s why the American Astronomical Society, the largest national association of astronomers, has agreed to host the Worldwide Telescope, software that provides a window into the multiwavelength universe.

A Browser for the Universe

WorldWide Telescope is basically a virtual observatory, an online portal that theoretically allows access to any dataset ever taken. Anyone, researcher, amateur astronomer, or grade-school student, can open the application and see the galaxy as imaged by the Digitized Sky Survey, then overplot gamma-ray data from Planck or zoom in to a tour of Mars. (See more on the WorldWide Telescope’s uses in our April 2015 issue and accompanying online article, “How to Use the WorldWide Telescope.”)

The program began in 2008 under the auspices of Microsoft Research, which released a free desktop application for Windows systems. Soon a web application was developed, so the software could be used on any computer or device, not just a PC. And in 2015, the software went open-source to encourage a broader community to work on the code’s development.

Now the American Astronomical Society is taking over leadership of the project, a development that promises to revolutionize the way astronomers show their research to other professionals and to the public.

One of the first orders of business is to make research papers more interactive. Astronomers can now present their data in the form of video abstracts. In these mini-tours, the author takes a few minutes to guide the reader through their observations. They’re intended for professional audiences but are far more accessible to the average reader, too. Take a look at these two examples:

And the interactivity isn’t limited to the paper abstract. Figures within the paper will soon be interactive, too. When readers click on an image, they’ll then be able to zoom in or out, superimpose observations at other wavelengths, or even add their own data set. Here’s one example, Richard Barnard’s 100-year-old image of the Rho Ophiuchus star-forming complex. Click on the image to open it in WorldWide Telescope, then go explore!

Rho Ophiuchus by Barnard

This 100-year-old image was taken by Barnard of the Rho Ophiuchus star-forming complex. Click through to explore this image in context within the WorldWide Telescope: zoom out to see its place in the Milky Way, browse nearby objects, or start playing with overlaying other datasets.
Edward Emerson Barnard Photographic Atlas of Selected Regions of the Milky Way

To make all of this happen, a lot needs to be done behind the scenes: the WWT team is working to import more data sets, such as all-sky surveys into the program, and they’re also building tutorials and how-tos that will tell astronomers how to add their own observations, create their own video abstracts, and more.

But the benefits of WorldWide Telescope won’t be limited to professional astronomers — there’s lots of opportunity for outreach, both in schools and planetariums.

“Publishing is going to drive [development], and then once it gets going, schools will be the first to adopt it en masse,” predicts WWT team member Doug Roberts (Northwestern University).

In fact, there’s already an associated outreach program, the WorldWide Telescope Ambassadors. The program provides teachers with lesson plans (with more under development) that that they can use in front of the class or in lab settings, where students are encouraged to explore on their own. Graduate students, postdocs, and retired astronomers also travel out to classrooms as ambassadors, helping teach the phases of the Moon to a third-grade classroom or explaining deep surveys of the early universe to a university class.

After spending years moving the WorldWide Telescope from its original home with Microsoft to its open-source home at Github, and now to AAS leadership, Roberts is looking forward to fast-tracking the software’s potential. “Next year is going to be a big year for us.

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Saturday Morning: Moon, Venus, and Mercury

Fri, 02/05/2016 - 07:13

Two planets and a pretty crescent Moon gather low above the southeastern horizon before dawn on February 6th.

Venus-Mercury-Moon in early February 2016

Mercury won't be well up in the morning sky for long, but on February 6th it creates a terrific triad with much brighter Venus and a very thin crescent Moon.
Sky & Telescope diagram

Don't sleep in tomorrow morning. Sure, it's Saturday, but it'll be worth getting up early to see dazzling Venus, elusive Mercury, and a razor-thin crescent Moon clustered together low in the southeast.

You'll need to be outside and ready about 45 minutes before sunrise, roughly 6 a.m. (depending on your location). Find a spot with a clear, unobstructed view toward southeast. Bring binoculars if you have them.

Your reward will be a view of Venus, Mercury, and a thin crescent Moon clustered within about 5° of one another — they should all fit within the field of view of low-power binoculars.

Predawn planetary geometry on February 6th

A closer look at the clustered thin Moon, Venus, and Mercury on February 6th before dawn.

Mercury might be challenging to spot, because it appears only 1% as bright as Venus does. But use the brighter planet as your guide: look toward its lower left, at roughly the 8 o'clock position, by about the width of your three middle fingers held together at arm's length.

The  extremely thin waning lunar crescent, to the upper left of both planets, will be especially pretty. It'll be just 48 hours from new Moon. Be alert for the faint glow of earthshine on the dark portion of its disk.

The Moon is ending its week-long "bombing" of the ongoing five-planet parade. You'll have at least another week to enjoy the show, which will end its satisfying run (to rave reviews) once Mercury slips too deeply in the predawn twilight and exits Stage Southeast.

The coming year offers lots of other celestial sights, and there's no better guide to enjoying them than SkyWatch 2016. Its constellation maps and observing guides perfect for novice stargazers and anyone who's ever been amazed by the beauty of the night sky.

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Adaptive Optics: Before and After

Thu, 02/04/2016 - 14:03

In the May 2016 issue of Sky & Telescope, Shannon Hall covers the past, present, and future of adaptive optics (AO), the technology that has allowed astronomers to conquer the tempestuous atmosphere.

The effect of adaptive optics is immediately visible (and astounding), so we're including here a full gallery of images that demonstrate the before and after, including several images that we didn't have room for in the magazine.

This simple animation shows how turning on the AO system at the Keck Observatory in Hawai'i improves visibility toward our galaxy's center:

Adaptive Optics in the Galactic Center

UCLA Galactic Center Group / W. M. Keck Observatory Laser Team

Though adaptive optics can be done with natural guide stars (i.e., by utilizing a nearby bright star in the sky), it's not always feasible, especially over a wide field of view. When bright stars are not available, observatories implement laser guide stars, a bright artificial star created by shining a laser beam into the sky. The image below shows the improvement from a natural guide star image of the galactic center (right) with a laser guide star image of the same field (left).

Natural Guide Star vs. Laser Guide Star

UCLA Galactic Center Group - W.M. Keck Observatory Laser Team

A similarly themed animation shows a view of our galaxy's central 0.5 arcseconds. The left panel shows the view with current AO technology, the central panel shows the view with next-gen AO, which will include multiple laser-generated guide stars. The right panel demonstrates the potential of the European Extremely Large Telescope, which will feature a beast of a 39-meter primary mirror.

UCLA Galactic Center Group / W. M. Keck Observatory Laser Team

An early AO system at Palomar Observatory sussed out a pair of stars in the IW Tau binary system with a separation of 0.3 arcseconds.

IW Tau, before and after AO

Palomar Observatory / NASA-JPL

AO systems can be turned closer to home too. Features in Uranus's atmosphere such as storms and banding sharpened dramatically once AO was enabled on the Keck Observatory. The image below was taken in 2004 from the Keck II telescope.

Uranus before and after AO

Heidi B. Hammel and Imke de Pater

Here's another example, this time with Neptune as the subject:

Neptune, before and after AO

University of California, Santa Cruz

Laser Light Shows

Almost every telescope on Mauna Kea, Hawai'i, uses laser guide star systems for observations. Watch them in action:

Though many observatories use custom-built sodium lasers, green-tinted Rayleigh lasers are sometimes used instead due to their commercial availability. Watch the ARGOS laser guide star in action at the Large Binocular Telescope:

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NGC 891 Wide field

Thu, 02/04/2016 - 12:55

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NGC 891 Cropped

Thu, 02/04/2016 - 12:52

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Rosette Nebula DSLR

Thu, 02/04/2016 - 12:43

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Orion Nebula trapezium close up

Thu, 02/04/2016 - 12:40

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Orion Nebula and the Running Man

Thu, 02/04/2016 - 12:36
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Rosette Nebula red Channel

Thu, 02/04/2016 - 09:25

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Rosette Nebula

Thu, 02/04/2016 - 08:41

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Thu, 02/04/2016 - 08:30

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Camden County Astronomy Club

Thu, 02/04/2016 - 05:04

Camden County Astronomy Club


Central Bank of the Ozarks
Missouri 65079 USA


Ginny Strogen








Our Club has a 10 acre dark sky site in Montreal, MO. We have also to date built 2 observatory buildings on our dark sky site that we open to the public by arrangement.

Meetings are held every month except December, on the 3rd Saturday of the month. Joining is simple and free. Meeting times are 7pm during CDT months and 6pm during CST months. Call or write for additional info.

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It’s Not Over Till The Fast Planet Sinks

Wed, 02/03/2016 - 05:08

This week and early next will be your last chance to see five planets — six if you count Earth — at dawn. Nature's even throwing in a bonus Mercury–Moon conjunction.

Wide-vision Vista

The author demonstrates the wide span — 115° this week — between the five morning sky planets on Sunday, January 31, at dawn, when a bright last-quarter Moon dominated the sky.
Bob King

People ask me whether they might still see "five planets in a row," and my answer remains an emphatic "yes!". But there's a deadline coming, so I encourage you to have a look at dawn either this week or early next. By Valentine's Day, the show's pretty much over. Five will drop to four.

Slip-slidin' Down the Ecliptic

Five planets and a bright Moon at dawn photographed over Rome on February 1, 2016.
Gianluca Masi

Although the Moon shined over-bright during my morning foray on Sunday, it thins this week to a crescent and meets Mercury in a striking conjunction two days before new Moon. Right now is also the best time to catch Mercury, which crests around 7° altitude (from 40° N)  before it's lost in bright twilight. The planet has been pushing west into the morning sky since late January, rising a little higher each morning. Come Saturday (February 6) it reverses direction and traipses back toward the Sun.

Flat's Where It's At

Thursday morning, February 4, about 45 minutes before sunrise from the central U.S. at 40° N latitude. Moon positions are shown through Saturday.

As pointed out in an earlier story by Sky & Telescope's Kelly Beatty, the planets neatly follow the arc of the ecliptic, the plane of Earth's orbit projected as a line into space and traced out by the Sun once a year. Rarely has the essential flatness of the solar system been rendered so obvious to the naked eye. For the new student of astronomy trying to make sense of where the planets travel, there's no more instructive time than now to see the concept in the flesh.

The last time the planets lined up like this occurred 11 years ago in late December 2004–early January 2005. It next occurs in August, making 2016 rich in multiple-planets-at-a-glance sightings.

Planetary Geometry

A closer look at the conjunction of the thin Moon and Mercury on Saturday morning, Feb. 6 at dawn.

To plan your outing, find a suitable location with a wide open view to the south and particularly to the southeast, where the low-lying planets Venus and Mercury will be hiding out. Arise about 1-1/2 hours before sunrise when the first hint of dawn brightens the eastern sky and get set up for viewing.

Jupiter stands relatively high in the southwestern sky at this time; it's brilliance makes it easy to identify. To find the other four, reach your balled fist to the sky and count off three fists to the left of Jupiter to arrive at Spica, Virgo's brightest star. Two fists further left (east), you'll bump into fire-colored Mars. A fainter star teases your eye a little more than 1° to the lower right of the planet. That's the tongue-teaser Zubenelgenubi, Libra's second brightest star, which sits almost directly on the ecliptic.

Summer Encore

After a reshuffle, five planets will again be visible at dusk in August this year.

Slide nearly three more fists to the east while dropping southward and say hello to Saturn and Antares. Saturn's the brighter and higher "star". Three more fists east and south will bring you to Venus, shining brilliantly despite its low altitude. Mercury glows just 5° — or three fingers — farther east and south.

Paired Together for Another Week

Mercury was even lower in the sky on Jan. 31 when this photo was taken but still very easy to see. This week it's higher yet.
Bob King

Take in the sight, the swelling light, and you'll be in orbit the rest of the day.

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amazing star trail

Tue, 02/02/2016 - 22:16

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Comet Catalina

Tue, 02/02/2016 - 13:45

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Oath Of Galileo

Tue, 02/02/2016 - 13:34

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Protected: Instructions for Posting on

Tue, 02/02/2016 - 09:15

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The Kavli Foundation Q&A: How Does Citizen Science Drive Discovery?

Tue, 02/02/2016 - 06:55

Crowd-sourcing the universe: Thanks to online portals, legions of volunteer astronomers are turning their eyes to the sky and doing extraordinary science. Three scientists discuss the future of citizen astronomy.

Gravitational Lens Candidates

A collage of the 29 new gravitational lensing candidates discovered by citizen scientists using Space Warps.
Space Warps / Canada-France-Hawaii Telescope Legacy Survey

Astronomers are increasingly enlisting volunteer "citizen scientists" to help them examine a seemingly endless stream of images and measurements of the universe. These volunteers' combined efforts are having a powerful impact on the study of the cosmos.

Just last November, a citizen science project called Space Warps announced the discovery of 29 new gravitational lenses, regions in the universe where massive objects bend the paths of photons (from galaxies and other light sources) as they travel toward Earth. As cosmic phenomena go, the lenses are highly prized by scientists because they offer tantalizing glimpses of objects too distant, and dim, to be seen through existing telescopes, as well as key information on the lensing objects themselves.

The Space Warps' haul of lenses is all the more impressive because of how it was obtained. During an eight-month period, about 37,000 volunteers combed through more than 430,000 digital images in a huge, online photo library of deep space. Automated computer programs have identified most of the 500 gravitational lenses on astronomer’s books. However, computers failed to flag the 29 lenses the Space Warps volunteers spotted, speaking to unique skills we humans possess.

In this Q&A, courtesy of The Kavli Foundation, three researchers discuss the possibilities of citizen science and especially the Space Warps project. All three are coauthors on two papers published in the Monthly Notices of the Royal Astronomical Society describing the Space Warps findings. In the Kavli Foundation's roundtable, the researchers discussed what was found and the critical role of citizen science in furthering astronomical discovery.

The participants:

  • Anupreeta More - is a project researcher at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU) at the University of Tokyo. More is a co-principal investigator for Space Warps, a citizen project dedicated to identifying gravitational lenses.
  • Aprajita Verma - is a senior researcher in the department of physics at the University of Oxford. Verma is also a co-principal investigator for Space Warps.
  • Chris Lintott - is a professor of astrophysics and the citizen science lead at the University of Oxford. Lintott is a co-founder of Galaxy Zoo, a citizen science project in which volunteers classify types of galaxies, and the principal investigator for the Zooniverse citizen science web portal.

The following is an edited transcript of the roundtable discussion. The participants have been provided the opportunity to amend or edit their remarks.

The Kavli Foundation: Anupreeta and Aprajita, where did you get the idea — along with your co-principal investigator Phil Marshall of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) at Stanford University — to put volunteers to work on identifying gravitational lenses starting back in 2013?

ANUPREETA MORE: A few years ago, Chris Lintott gave a talk on citizen science at the Kavli Institute for Cosmological Physics in Chicago, where I was working at the time. It got me thinking about a lens search by citizen scientists.

APRAJITA VERMA: For Phil Marshall and I, Space Warps grew out of Galaxy Zoo. Soon after Galaxy Zoo launched, I started to look at some of the galaxies that were being posted on the Galaxy Zoo user forum that had potential lensed features surrounding them. This was a great by product of the core Galaxy Zoo project. However, we realized that to find these incredibly rare sources, which are often confused with other objects, we really needed a tailored interface to efficiently find lenses. This grew into Space Warps.

TKF: Chris, Galaxy Zoo itself was inspired by Stardust@home, the first astronomy-based citizen science project in which people played an active role. Until then, citizen scientists were often computer owners who offered up free processing power on their devices to aid in machine-driven data analysis. Were you concerned when you started Galaxy Zoo in 2007 that it would be hard to attract volunteers?

CHRIS LINTOTT: Since Stardust@home involved people looking at images of a comet's dust grains brought back by NASA's Stardust space probe, we thought "Well, if people are willing to look at dust grains, then surely they'd be happy to look at our galaxies!" But that turned out to be almost beside the point. As we've done many of these citizen science projects over the years, we've discovered it's not the quality of the images that matter. After all, our galaxies aren't typically beautiful. They are not the Hubble Space Telescope shots that you’d expect to find on the front page of the New York Times. Our galaxies are often fuzzy, little, enigmatic blobs. The Space Warps images are pretty, but again they're not the kind of thing you would sell as a poster in the gift shop at the Kennedy Space Center.

It's actually the ideas that get people excited. I think Space Warps and Galaxy Zoo have been successful because they have done a great job of explaining to people why we need their help. We're saying to them: "Look, if you do this simple task, it allows us to do science." This idea is best shown by Planet Hunters, a citizen science project that searches for exoplanets in data from NASA's Kepler spacecraft. Users are looking at graphs for fun. But because the idea is the discovery of exoplanets, people will put up with looking at data.

TKF: What sort of unique science is made possible because of Space Warps?

VERMA: Gravitational lenses allow us to look at objects, such as very distant galaxies, that are fainter and in much more detail than with the telescopes we have now. It's enabling the kind of science we'll be routinely doing with extremely large telescopes in the future.

MORE: That's right. Something unique about gravitational lensing is that it acts like a natural telescope and allows us to study some really faint, distant galaxies which we wouldn't get to study otherwise. We're seeing these distant galaxies in the early stages of their life cycle, which helps us understand how galaxies evolve over time.

Also, in a gravitational lens system, it's possible for us to study the properties of the foreground galaxies or galaxy groups that are gravitationally lensing the background sources. For example, we can measure the mass of these foreground galaxies and also study how mass is distributed in them.

TKF: Space Warps and other citizen science projects flourish because computer programs sometimes struggle at identifying features in data. Why do computers have trouble spotting the characteristic arc or blobby shapes of gravitational lenses that humans can?

MORE: The problem is that these arc-like images of distant galaxies can have very different shapes and profiles. The process of lensing magnifies these galaxies' images and can distort them. Also, these distant galaxies emit light at different wavelengths and can appear to have different colors. Furthermore, there are structures in these galaxies that can change the shape of the arcs.

VERMA: Also, lots of spiral galaxies have bluish spiral arms that can look like lenses. We call these objects "lens impostors" and we find many more of these false positives compared to rare, true gravitational lenses.

MORE: All these differences make it difficult to automate the process for finding lenses. But human beings are very good at pattern recognition. The dynamic range that our eyes and our brains offer is much greater than a computer algorithm.

LINTOTT: Another thing to bear in mind in astronomy, particularly in Space Warps, is that we're often looking for rare objects. A computer's performance depends very strongly on how many examples you have to "train" it with. When you're dealing with rare things, that's often very difficult to do. We can't assemble large collections of hundreds of thousands of examples of gravitational lenses because we don't have them yet.

Also, people — unlike computers — check beyond what we are telling them to look for when they review images. One of the great Space Warps examples is the discovery of a "red ring" gravitational lens. All the example lenses on the Space Warps site are blue in color. But because we have human classifiers, they had no trouble noticing this red thing that looks a little like these blue things they've been taught to keep an eye out for. Humans have an ability to make intuitive leaps like that, and that's very important.

VERMA: I echo the point that it's very difficult to program diversity and adaptability into any computer algorithm, whereas we kind of get it for free from the citizen scientists! [Laughter]

TKF: Aprajita and Anupreeta, what’s the importance of the red ring object Chris just mentioned that the Space Warps community discovered in 2014 and has nicknamed 9io9?

VERMA: This object was a really exciting find, and it's a classic example of something we hadn't seen before that citizen scientists quickly found. We think that inside the background galaxy there's both an active black hole, which is producing radio wave emissions, as well as regions of star-formation. They're both stretched by the lensing into these spectacular arcs. It's just a really nice example of what lensing can do. We're still putting in further observations to try and really understand what this object is like.

MORE: In this particular case with 9io9, there is the usual, main lensing galaxy, but then there is also another, small, satellite galaxy, whose mass and gravity are also contributing to the lensing. The satellite galaxy produces visible effects on the lensed images and we can use this to study its mass distribution. There are no other methods besides gravitational lensing which can provide as accurate a mass estimate for galaxies at such great distances.

TKF: Besides 9io9, citizen astrophysicists have turned up other bizarre, previously unknown phenomena. One example is Hanny’s Voorwerp, a galaxy-size gas cloud discovered in 2007 in Galaxy Zoo. More recently, in 2015, Planet Hunters spotted huge decreases in the starlight coming from a star called KIC 8462. The cause could be an eclipsing swarm of comets; another, albeit unlikely, possibility that has set off rampant speculation on the Internet is that an alien megastructure is blocking light from the star. Why does citizen science seemingly work so well at making completely unexpected discoveries?

LINTOTT: I often talk about the human ability to be distracted as a good thing. If we're doing a routine task and something unusual comes along, we stop to pay attention to it. That's rather hard to develop with automated computer systems. They can look for anomalies, but in astronomy, most anomalies are boring, such as satellites crossing in front of the telescope, or the telescope's camera malfunctions.

However, humans are really good at spotting interesting anomalies like Hanny's Voorwerp, which looks like either an amorphous green blob or an evil Kermit the Frog, depending on how you squint at it. [Laughter] The point is, it's something you want to pay attention to.

The other great thing about citizen science is that the volunteers who find these unusual things start to investigate and become advocates for them. Citizen scientists will jump up and down and tell us professional scientists we should pay attention to something. The great Zooniverse discoveries have always been from that combination of somebody who's distracted and then asks questions about what he or she has found.

TKF: Aprajita and Chris, you are both working on the Large Synoptic Survey Telescope (LSST). It will conduct the largest-ever scan of the sky starting in 2022 and should turn up tons of new gravitational lenses. Do you envision a Space Warps-style citizen science project for LSST?

VERMA: Citizens will play a huge role in the LSST, which is a game-changer for lensing. We know of about 500 lenses currently. LSST will find on the order of tens to hundreds of thousands of lenses. We will potentially require the skill that citizen scientists have in looking for exotic and challenging objects.

Also, LSST’s dataset will have a time dimension. We're really going to make a movie of the universe, and this will turn up a number of surprises. I can see citizen scientists being instrumental in a lot of the discoveries LSST will make.

LINTOTT: One thing that's challenging about LSST is the sheer size of the dataset. If you were a citizen scientist, say, who had subscribed to receive text message alerts for when objects change in the sky as LSST makes its movie of the universe, then you would end up with a couple of billion text messages a night. Obviously that would not work. So that means we need to filter the data. We'll dynamically decide whether to assign a task to a machine or to a citizen scientist, or indeed to a professional scientist.

TKF: Chris, that comment reminds me of something you said to TIME magazine in 2008: "In many parts of science, we're not constrained by what data we can get, we're constrained by what we can do with the data we have. Citizen science is a very powerful way of solving that problem.” In this era of big data, how important do you all see citizen science being moving forward, given that computers will surely get better at visual recognition tasks?

LINTOTT: In astronomy, if you're looking at things that are routine, like a spiral galaxy or a common type of supernova, I think the machines will take over. They will do so having been trained on the large datasets that citizen scientists will provide. But I think there will be citizen involvement for a long while and it will become more interesting as we use machines to do more of the routine work and filter the data. The tasks for citizen scientists will involve more varied things — more of the unusual, Hanny's Voorwerp-type of discoveries. Plus, a lot of unusual discoveries will need to be followed up, and I'd like to see citizen scientists get further into the process of analysis. Without them, I think we're going to end up with a pile of interesting objects which professional scientists just don't have time to deal with.

VERMA: We have already seen a huge commitment from citizen scientists, particularly those who've spent a long time on Galaxy Zoo and Space Warps. For example, on Space Warps, we have a group of people who are interested in doing gravitational lens modeling, which has long been the domain of the professional astronomer. So we know that there's an appetite there to do further analysis with the objects they’ve found. I think in the future, the citizen science community will work hand-in-hand with professional astronomers.

TKF: Are there new citizen astrophysicist opportunities on the horizon related to your projects?

LINTOTT: Galaxy Zoo has a new lease on life, actually. We just added in new galaxies from a telescope in Chile. These galaxies are relatively close and their images are beautiful. It's our first proper look at the southern sky, so we have an all-new part of the universe to explore. It gives users a chance to be the first to see galaxies — if they get over to Galaxy Zoo quickly!

VERMA: For Space Warps, we are expecting new data and new projects to be online next year.

MORE: Here in Japan, we are leading an imaging survey called the Hyper Suprime-Cam (HSC) survey and it's going to be much larger and deeper than what we have been looking at so far. We expect to find more than an order of magnitude increase in the number of lenses. Currently, we are preparing images of the candidates from the HSC survey and hope to start a new lens search with Space Warps soon.

Hanny's Voorwerp

Arguably the most famous citizen astrophysicist discovery, Hanny's Voorwerp—Dutch for Hanny's Object—is seen here by the Hubble Space Telescope in 2011. The Voorwerp is a gas cloud the size of galaxy and appears green due to glowing oxygen. A Dutch schoolteacher, Hanny van Arkel, spotted the object while volunteering for Galaxy Zoo.
NASA / ESA / W. Keel / Galaxy Zoo Team

TKF: Is it the thrill of discovery that entices most citizen scientist volunteers? Some of the images in Galaxy Zoo have never been seen before because they were taken by a robotic telescope and stored away. Volunteers therefore have the chance to see something no one else ever has.

MORE: That discovery aspect is personal. I think it's always exciting for anyone.

LINTOTT: When we set up Galaxy Zoo, we thought it would be a huge motivation to see something that's yours and be the first human to lay eyes on a galaxy. Exploring space in that way is something that until Galaxy Zoo only happened on "Star Trek." [Laughter]

In the years since, we've also come to realize that citizen science is a collective endeavor. The people who've been through 10,000 images without finding anything have contributed to the discovery of something like the red ring galaxy just as much as the person who happens to stumble across it. You need to get rid of the empty data as well. I've been surprised by how much our volunteers believe that. It's a far cry from the traditional, public view of scientific discovery in which the lone genius makes the discovery and gets all the credit.

VERMA: We set out with Space Warps for citizen scientists to be part of our collaboration and they've really enabled us to produce important findings. They've inspired us with their dedication and productivity. We've learned from our analysis that basically anyone who joins Space Warps has an impact on the results. We are also especially grateful for a very dedicated, diligent group that has made most of the lens classifications. We look forward to welcoming everyone back in our future projects!

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