Posted on by Tammy Plotner

Voorwerpje… And Away!

UGC 7342 in H-Alpha - Credit: Galaxy Zoo

[/caption]It’s 28 pages long and it has been submitted to the Monthly Notices of the Royal Astronomical Society. It’s filled with exciting new discoveries. What is it? Try the Galaxy Zoo’s latest findings… the Great Voorwerpje Round-up!

“Eighteen thousand candidate active galactic nuclei. One hundred ninety-nine Zooites. A hundred fifty-four possible galaxies with clouds, of which 49 became targets for spectra. And finally, nineteen certified Voorwerpjes – giant clouds of gas ionized by a central active nucleus, like Hanny’s Voorwerp but smaller (and sometimes not all that much smaller) and dimmer.” says Bill Keel. “Of these clouds, many (including the largest) are new discoveries.”

The Galaxy Zoo has been on the hunt and what they’ve found has proved to be very exciting to the team. Says Keel: “About half of these have gas too highly ionized too far from the nucleus to account for by the nucleus we see (even including far-infrared results to tell how much radiation is being absorbed by dust), so they may be additional, less dramatic instances of the AGN fading over time spans of 100,000 years or so. This large fraction suggests that at least Seyfert nuclei may constantly be brightening and fading over times of a few hundred thousands years (a time span about which we’ve previously had almost no information).”

Their images include those taken with filters that isolate [O III] or Ha emission – even subtracting ordinary starlight. In one such image of UGC 7342, they could trace gas out to twice the estimated size of the Milky Way! This could mean the presence of an AGN. “Starlight doesn’t have enough far-ultraviolet or X-rays to make gas that highly ionized, but an active galactic nucleus does. Furthermore, the ratios of these lines let us estimate how intense this radiation is when it reaches a cloud.” comments Keel. “Even though UGC 7342 is pretty chewed up because of an interaction with at least one companion, the gas motions aren’t as chaotic as they might be – the gas isn’t orbiting retrograde or anything.”

Their research is shedding new light on Voorwerpje mysteries – giving consistencies to ionized clouds located in galaxies which are interacting or merging – and accounting for tidal disturbances. Preliminary findings also show a symmetry as well, where around 50% of the galaxies studied show two ionized clouds on opposite sides.

“Of course, we want to know more. Answers tend to multiply questions. Hubble observations are scheduled, and (with a little luck) X-ray measurements with ESA’s XMM-Newton observatory. We’ve managed to interest some of the people at ASTRON in the Netherlands in using the Westerbork array to examine the cold hydrogen around these galaxies.” says Keel. “In addition, we’re doing new observations of various samples of active and “nonactive” galaxies to look for fainter, and maybe older, gas clouds. Special thanks to everyone who participated in this project, either through the targeted hunt or the complementary forum search for clouds in galaxies not listed as AGN. Stay tuned!”

You can bet we will…

Original Story Source: Zooniverse Blog.

Posted on by Tammy Plotner

Kepler Drops In On Planetary Nebula

Gemini Observatory image of Kronberger 61 showing the ionized shell of expelled gas resembling a soccer ball. The light of the nebula here is primarily due to emission from twice-ionized oxygen, and its central star can be seen as the slightly bluer star very close to the center of the nebula. Credit: Gemini Observatory/AURA

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Discovered by amateur Austrian astronomer, Matthias Kronberger, planetary nebula Kn 61 just happens to be in a relatively small piece of celestial real estate being monitored by NASA’s Kepler planet finding mission. Lucky for us, we’re able to take a look at the photographic results of the new nebula obtained with the Gemini Observatory.

“Kn 61 is among a rather small collection of planetary nebulae that are strategically placed within Kepler’s gaze,” said Orsola De Marco of Macquarie University in Sydney, Australia who is the author of a 2009 paper speculating on how companion stars or even planets may influence and shape the intricate structure seen in many planetary nebulae. “Explaining the puffs left behind when medium sized stars like our Sun expel their last-breaths is a source of heated debate among astronomers, especially the part that companions might play,” says De Marco, “it literally keeps us up at night!”

And visions like this keeps the Kepler Mission continually monitoring a 105 square degree area of sky located in Cygnus looking for changes in stellar brightness which could spell a planetary transit, companion star – or something else. “It is a gamble that possible companions, or even planets, can be found due to these usually small light variations,” says George Jacoby of the Giant Magellan Telescope Organization and the Carnegie Observatories (Pasadena). “However, with enough objects it becomes statistically very likely that we will uncover several where the geometries are favorable – we are playing an odds game and it isn’t yet known if Kn 61 will prove to have a companion.” Jacoby also serves as the Principal Investigator for a program to obtain follow-up observations of Kn 61’s central star with Kepler.

To help sift through the huge amount of data provided by Kepler, professional and amateur astronomers are working as partners to help locate objects such as planetary nebula. So far, six have been found in the digital sky survey – including Kn 61. “Without this close collaboration with amateurs, this discovery would probably not have been made before the end of the Kepler mission. Professionals, using precious telescope time, aren’t as flexible as amateurs who did this using existing data and in their spare time. This was a fantastic pro-am collaboration of discovery,” says Jacoby, who serves as the liaison with the Deep Sky Hunters (DSH) and requested their help to survey the Kepler field. Jacoby published a paper with DSH members in 2010 that describes the techniques used.

“Planetary nebulae present a profound mystery,” says De Marco. “Some recent theories suggest that planetary nebulae form only in close binary or even planetary systems – on the other hand, the conventional textbook explanation is that most stars, even solo stars like our sun, will meet this fate. That might just be too simple.” Jacoby also elucidates that terrestrial observations are unable to detect such phenomena with a high rate of regularity “This is quite likely due to our inability to detect these binaries from the ground and if so then Kepler is likely to push the debate strongly in one direction or the other.”

As for our own galaxy, over 3,000 planetary nebulae have been identified and cataloged. We know they are the end product of a dying star, but not what role companions stars (or even planets) may take in their structure. Of these, only 20% have binary central stars – but this low number may be our inability to resolve them. Hopefully the space-based Kepler telescope can one day reveal their mysteries us!

Original News Source: Gemini Observatory Image Release.

Posted on by Tammy Plotner

Sometimes You Feel Like A Quark… And Sometimes You Don’t

A recent prank involving the reenactment of a human sacrifice has got officials at CERN kind of miffed! Credit: CERN

[/caption]It’s a Higgs boson. No. We’re not talking about some swarthy seaman standing at the helm of a boat and keeping watch. We’re talking about a hypothetical massive elementary particle predicted to exist by the Standard Model of particle physics. Its presence is supposed to help explain our lack of consistences when it comes to theoretical physics – and observing it has been one of the prime functions of the Large Hadron Collider. But the LHC hasn’t found it yet. As a matter of fact, we might wonder just what else it hasn’t found…

Right now, scientists have answered – or at least postulated the answer to – some very ponderous questions that lay just beyond the scope of the standard model. One of the foremost is the existence of dark matter. To find the solution, they’re using a model called supersymmetry. It’s an easy enough concept, one that states for every particle a stronger one echoes it at higher energy levels. The only trouble with this theory is that there isn’t any proof of these “super-particles” to be found yet. “Squarks” and “gluinos”, the antithesis of quarks and gluons, have been canceled out at energies up to 1 teraelectronvolts (TeV) of the standard model, according to an analysis of the LHC’s first year of collisions.

It should be easy, shouldn’t it? Given the broad spectrum, there should be simple members found within the supersymmetric models – even leaving the more complex and energetic to be explored at another time. But “the air is getting thin for supersymmetry”, says Guido Tonelli of the LHC’s CMS collaboration. At the same time, there is no sign yet of gravitons – particles that transmit gravity and are essential for a quantum theory of the force – below an energy of 2 TeV.

This lack of findings is causing some folks to wonder if we’re expecting answers to the wrong questions, but Rolf-Dieter Heuer, CERN’s director general is more optimistic. He knows the LHC has only produced about 1/1000th of its eventual data. “Something will come,” he says. “We just have to be patient.” But what of the Higgs boson? So far it has only been a blip on the LHC screen. “We will have answered the Higgs’s Shakespeare question – to be or not to be – by the end of next year,” Heuer predicts.

Original News Source: NewScientist News and Wikipedia.

Posted on by Tammy Plotner

Now Playing At The Sky Cinema… The Moon, Mars and Aldebaran

Illustration Courtesy of McDonald Observatory

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Be on morning alert from July 26 through July 28 as the Moon, Mars and Aldebaran put on a delightful sky show that doesn’t require any special equipment – just cooperative weather! While this motion picture doesn’t have any sound, what it will have is color to delight the eye.

When it comes to viewing the night sky, most people don’t perceive much color. Things mostly appear black and white – with a little gray on the Moon thrown in for good measure. With experience, most skywatchers easily pick out blue stars and faded green in nebula, but what really gets our hearts ticking is red. And very few stars show that ruddy hue to unaided vision as well as the eye of Taurus the Bull – Aldebaran.

On the morning of July 26th, about an hour before dawn, the waning crescent Moon will be very close to Alpha Tauri and the contrast will make for a spectacular showing. The following morning, it will hover just above Mars and slide into position just below on July 27th. Take the time to really look at what you’re seeing. Of the three principle players, the only one that generates its own light is Aldebaran… the rest are products of reflection. While the star’s russet tone comes from being a cool giant, Mars’ color comes from iron oxide. Not only is the Moon reflecting back sunlight, but you’ll also see the DaVinci effect where the “dark side” is gently illuminated as well.

Don’t be surprised if folks you know ask you what’s going on. Close conjunctions such as this excites the eye! Why? When it comes to our eyes, almost every photoreceptor has one ganglion cell receiving data in the fovea. That means there’s almost no data loss and the absence of blood vessels in the area means almost no loss of light either. There is direct passage to our receptors – an amazing 50% of the visual cortex in the brain! Since the fovea doesn’t have rods, it isn’t sensitive to dim lights. That’s another reason why the conjunctions are more attractive than the surrounding starfields. Astronomers know a lot about the fovea for a good reason: it’s why we learn to use averted vision.

But don’t avert your vision when it comes to enjoying this morning show!

Original News Source: McDonald Observatory StarDate News.

Posted on by Tammy Plotner

Shedding New Starlight On The Andromeda Galaxy

This image shows NASA/ESA Hubble Space Telescope images of a small part of the disc of the Andromeda Galaxy, the closest spiral galaxy to the Milky Way. Hubble’s position above the distorting effect of the atmosphere, combined with the galaxy’s relative proximity, means that the galaxy can be resolved into individual stars, rather than the cloudy white wisps usually seen in observations of galaxies. Credit: NASA, ESA and T.M. Brown (STScI)

Thanks to Hubble’s Advanced Camera for Surveys, we’re now able to take a deeper look into the Andromeda Galaxy than ever before. Four new images are giving us an unprecedented view of resolved stars – something that just doesn’t occur when looking at other galaxies. Although we can see M31 with unaided vision from a relatively dark sky site, there’s no way we can see the outer regions without a telescope. Now we’re resolving them…

Although astronomers are quite aware that spiral galaxies have great distances between their stellar members, it is one thing to know it and another to see it. High above our atmosphere, the Hubble has a clean view of one of our nearest galactic neighbors, and it’s not looking in a window – it is photographing the backyard. Not only are individual stars revealed, but even more distant galaxies can be seen in the background beyond Andromeda’s dense disc.

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But it’s not only there that other galaxies can be seen. Try looking through M31’s halo…

This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)

“The two images taken in M 31’s halo show the lowest density of stars. The halo is the huge and sparse sphere of stars that surrounds a galaxy.” says the team. “While there are relatively few stars in a galaxy’s halo, studies of the rotation rate of galaxies suggest that there is a great deal of invisible dark matter.”

This image shows NASA/ESA Hubble Space Telescope images of a small part of the halo of the Andromeda Galaxy. Credit: NASA, ESA and T.M. Brown (STScI)

But don’t forget the stellar stream. There the stars are more densely packed, causing light extinction – yet the Hubble is resolving them! Take a look at this multitude of stars which could be the remainder of a galaxy M31 absorbed in the past…

This image shows NASA/ESA Hubble Space Telescope images of a small part of the giant stellar stream of the Andromeda Galaxy. The stream is a long structure thought to be the remains of a companion galaxy torn apart by the Andromeda Galaxy’s gravity and engulfed in it. Credit: NASA, ESA and T.M. Brown (STScI)

“These observations were made in order to observe a wide variety of stars in Andromeda, ranging from faint main sequence stars like our own Sun, to the much brighter RR Lyrae stars, which are a type of variable star.” says the Hubble crew. “With these measurements, astronomers can determine the chemistry and ages of the stars in each part of the Andromeda Galaxy.”

And we can marvel at a look at galaxies which may have remained forever hidden if it weren’t for Hubble’s incredible eye.

Original News Source: ESA / Hubble News.

Posted on by Tammy Plotner

Exoplanet Aurora… Light ‘Em Up!

This artist's conception shows a "hot Jupiter" and its two hypothetical moons with a sunlike star in the background. The planet is cloaked in brilliant aurorae triggered by the impact of a coronal mass ejection. Theoretical calculations suggest that those aurorae could be 100-1000 times brighter than Earth's. Credit: David A. Aguilar (CfA)

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One of the most beautiful and mysterious apparitions – be it north or south – here on Earth is an auroral display. We know it’s caused by the Sun-Earth connection, so could it happen around exoplanets as well? New research shows that aurorae on distant “hot Jupiters” could be 100-1000 times brighter than Earthly aurorae, creating a show that would be… otherworldly!

“I’d love to get a reservation on a tour to see these aurorae!” said lead author Ofer Cohen, a SHINE-NSF postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics (CfA).

As we are now aware, aurorae occur here on Earth when the Sun’s energetic particles encounter our magnetosphere and are shifted towards the poles. This in turn excites the atmosphere, ionizing the particles. Much like turning on your electric stove, this causes the “element” to glow in visible light. It happens here… and it happens on Jupiter and Saturn as well. If other suns behave like our own and other planets have similar properties to those in our solar system, then the answer is clear.

Exoplanets have aurorae, too.

Cohen and his colleagues used computer models to study what would happen if a gas giant in a close orbit, just a few million miles from its star, were hit by a stellar blast. He wanted to learn the effect on the exoplanet’s atmosphere and surrounding magnetosphere. In this scenario, the solar storm is much more focused and far more concentrated when it impacts a “hot Jupiter”. In our solar system, a coronal mass ejection spreads out before it reaches us, but what would happen if it collided with a nearer planet?

“The impact to the exoplanet would be completely different than what we see in our solar system, and much more violent,” said co-author Vinay Kashyap of CfA.

Using modeling, the team took a look at the scenario. The solar blast would slice into the exoplanet’s atmosphere and weaken its magnetic shield. The auroral activity would then form a ring around the equator, 100-1000 times more energetic than seen here on Earth. It would then travel up and down the planet’s surface from pole to pole for hours, gradually weakening – yet the planet’s magnetosphere would save it from erosion. This type of study is important for understating habitable properties of Earth-like worlds.

“Our calculations show how well the planet’s protective mechanism works,” explained Cohen. “Even a planet with a magnetic field much weaker than Jupiter’s would stay relatively safe.”

Original News Source: Harvard-Smithsonian Center for Astrophysics News.

Posted on by Tammy Plotner

Caught In The Web… Space Spider!

IC 342's dust structures show up vividly in red, in this infrared view from Spitzer. Image credit: NASA/JPL-Caltech

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Look, he’s crawling up my wall… Black and hairy, very small… Now he’s up above my head… Hanging by a little thread. Nope. It’s not Boris the Spider, it’s spiral galaxy IC 342 and it’s hanging out in the constellation of Camelopardalis. Thanks to NASA’s Spitzer Space Telescope, we’re able to peer through the dust clouds and sneak a peek at this arachnid appearing beastie.

Residing at an approximate distance of 10 million light-years, this impressive grand design spiral is difficult for details because it’s located directly behind the disk of the Milky Way from our point of view. Tiny particles of interstellar dust, which measure just a fraction of a micron across, approximate the blue wavelength of light. These vast areas composed of silicates, carbon, ice, and/or iron compounds dim the light in a process called extinction – but using infrared vision can even the score. Line-of-sight stars from our galaxy appear blue/white and the blue haze around the galaxy’s nucleus is from IC 342’s collective starlight. Its gangly arms glow a soft crimson and clumps of newly forming stars radiate red.

It’s small wonder the core of IC 342 appears so spooky. According to research, it has undergone a recent burst of star formation activity and is close enough to have gravitationally influenced the evolution of the local group of galaxies and the Milky Way. Can you observe Boris yourself? Absolutely. You’ll find this magnitude 9 critter located along the galactic equator at RA 03h 46m 48.5s – Dec +68 05′ 46″. But beware… Its low surface brightness means you’ll need a rich field telescope and good, dark skies.

Creepy, crawly… Creepy, crawly… Creepy, creepy, crawly, crawly…

Original News Source: JPL / Spitzer News.

Posted on by Tammy Plotner

Elliptical Galaxies Don’t Act Their Age…

The galaxy NGC 5557 clearly exhibits extremely extended and faint tidal streams spanning more than 1.2 million light-years from left to right on this image from the MegaCam mounted on the Canada-France-Hawaii Telescope. Image by P.-A. Duc 2011 (c) CEA/CFHT

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Thanks to images taken with the MegaCam camera mounted on the Canada-France-Hawaii Telescope (CFHT, CNRC/CNRS/University of Hawaii), researchers are beginning to see that elliptical galaxies just aren’t acting their age. Their initial studies are showing signs of recent merging – meaning that many could be as much as five times younger than previously thought.

We’ve been studying massive elliptical galaxies for a long time and their stripped down stellar population has always led astronomers to assume most were in the 7 to 10 billion year old age bracket. However, astronomers from CNRS, CEA, CFHT, and the Observatoire de Lyon – all members of the Atlas3D international collaboration – have been sneaking a peak at the galactic fountain of youth. According to observations done on two elliptical galaxies (NGC 680 & NGC 5557), it would appear they’ve undergone a spiral galaxy merger… one that’s happened as recently as 1 to 3 billion years ago.

“Such age estimate is based on the presence of ultra faint filaments in the distant outskirts of the galaxies. These features called tidal streams in the astronomers parlance are typical residuals from a galaxy merger.” says the CFH team. “They are known not to survive in this shape and brightness for more than a few billion years, hence the new age estimate of the resulting elliptical galaxies. These structures were detected for the first time thanks to a very-deep imaging technique boosting the capabilities of CFHT’s wide-field optical imager MegaCam.”

A sample of elliptical galaxies from the Atlas3D survey current collection, all showing clear signs of a recent collision. Image by P.-A. Duc 2011 (c) CEA/CFHT

The Atlas3D team isn’t stopping with these results and they’re looking at a survey of more than one hundred elliptical galaxies close to the Milky Way. When the samples are gathered and compared, they’ll look for more faint extended features that could spell a recent merger. It could mean we need to rethink our standard model for elliptical galaxies formation!

Maybe even ask ’em for ID…

Original News Source: CFH News.

Posted on by Tammy Plotner

Forever Blowing Bubbles…

ESO’s Very Large Telescope has been used to obtain this view of the nebula LHA 120-N 44 surrounding the star cluster NGC 1929. Lying within the Large Magellanic Cloud, a satellite galaxy of our own Milky Way, this region of star formation features a colossal superbubble of material expanding outwards due to the influence of the cluster of young stars at its heart that sculpts the interstellar landscape and drives forward the nebula’s evolution. Credit: ESO/Manu Mejias

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Thanks to ESO’s Hidden Treasures 2010 astrophotography competition, Manu Mejias, from Argentina compiled the data to give us a view of a cosmic superbubble that staggers the imagination with its size. Spanning around around 325 by 250 light-years across, we’d never realize the true nature of this phenomenon if it wasn’t so far away.

Officially designated as LHA 120–N 44, this sprawling complex of hot gases makes its home in the Large Magellanic Cloud. Skirting its edge is young star cluster, NGC 1929, whose intense ultra-violet radiation paints the visible portrait of stellar winds in action. To give you a good idea of just how big this super-bubble really is, take a look at this awesome map from Atlas Of The Universe.

This map is a plot of the 1500 most luminous stars within 250 light years. All of these stars are much more luminous than the Sun and most of them can be seen with the naked eye. About one third of the stars visible with the naked eye lie within 250 light years, even though this is only a tiny part of our galaxy. Credit: Richard Powell

Can you conceive of a nebula so large that it stretched from Cassiopeia to Vela in one direction and far further than Ursa Major to Phoenix in the other? Like a bracelet around the arm of the Milky Way, it would be so huge we probably wouldn’t even be aware it was there. Now that’s a super superbubble!

Picture a soapy mixture being stretched to the breaking point… the massive stars embedded in the nearby clusters going supernova – creating shockwaves and expelled gases. Like the child blowing the bubble, the stellar winds continued to expel, clearing the center of material. At the perimeters, new stars are continuing to form where the gases are compressed. It’s the nature of the beast… cosmic recycling in action.

Many thanks go to Manu Mejias for taking a look at a really BIG picture!

Original Story Source: ESO Photo Release. And thanks to Richard Powell of Atlas Of The Universe.

Posted on by Tammy Plotner

Cosmic Crime Alert… LMC Is Swiping Stars!

The Milky Way’s near neighbor, the Large Magellanic Cloud (LMC), has accreted a smattering of stars from its smaller neighbor, the Small Magellanic Cloud (SMC). In this image, the LMC is shown as it appears in observations by the Spitzer Space Telescope at 3.6, 8.0, and 24 microns. Overlaid in red and blue, with colors representing the light of sight velocities (red = away, blue = towards) are the locations of stars whose origin has been traced to the SMC. These stars were discovered by a team led by NOAO astronomer Knut Olsen, through analysis of spectra obtained at the CTIO 4-m Blanco telescope. Spitzer image credit: Karl Gordon and Margaret Meixner (Space Telescope Science Institute/AURA/NASA). Compilation by K. Olsen (NOAO/AURA/NSF))

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Using the Spitzer Space Telescope, a team of astronomers from the National Optical Astronomy Observatory (NOAO) have made a unique discovery. Our neighbor – the Large Magellanic Cloud – has been caught pilfering stars from the Small Magellanic Cloud! What caused this cosmic crime and what do we know about it? Read on…

Through the use of spectra, 5900 giant and supergiant stars in the Large Magellanic Cloud have been identified as once belonging to the nearby Small Magellanic Cloud. NOAO astronomers Knut Olsen and Bob Blum, and their collaborators Dennis Zaritsky (University of Arizona), and Martha Boyer and Karl Gordon (Space Telescope Science Institute) were hot on the trail as they ascertained a counter rotation in a small percentage of the stellar population. Although they could only take information from “line of sight” stars, this 5% was enough to give them a clue they weren’t formed where they are now located. Even their chemical signature isn’t right!

“Further examination of these counter-rotating stars revealed another anomaly. The chemical composition of these stars is different. They have fewer heavy elements such as iron and calcium than typical stars in the Large Magellanic Cloud.” say the team. “However, their composition closely matches that of stars in another nearby galaxy, the Small Magellanic Cloud, whose stars are also depleted in these “metals”.

Just like fingerprints, these two signatures – motion and composition – are a dead giveaway that these certain stars have been lifted by gravitational interaction. To further refine the evidence the group used the multi-object spectrometer on the Cerro Tololo Inter-American Observatory 4-meter Blanco Telescope in Chile to observe 4600 stars, and their spectra, simultaneously. When compared to 1300 other stars, a pattern begin to emerge. According to Olsen “It is not always easy to tell whether the stars in a galaxy formed in the galaxy or formed somewhere else and then were captured. Since the LMC is so close to us, we were able to observe a large number of individual stars. And to our surprise, the LMC contained a significant number of stars that must have formed elsewhere.”

Continuing their investigations with the Spitzer Space Telescope, the team is also involved with stellar evolution studies in the LMC. NOAO Deputy Director Bob Blum indicated the importance of this approach: “Using observations with the Spitzer Space Telescope, we were able to get a complete census of the stellar populations in the LMC. With the ground-based observations we could determine the properties and motions of a large sample of stars throughout that galaxy. By combining both, we were able to tell that some of the stars must have come from the neighboring SMC. This led us to a deeper understanding of how galaxies can and do interact, and change over time.”

These studies may help us to further understand high rates of star formation in areas like 30 Doradus… When we’re not just stealin’ a look.

Original News Source: NOAO News.