Posted on by Jason Major

Runaway Star Shocks the Galaxy!

The speeding rogue star Kappa Cassiopeiae sets up a glowing bow shock in this Spitzer image (NASA/JPL-Caltech)

That might seem like a sensational headline worthy of a supermarket tabloid but, taken in context, it’s exactly what’s happening here!

The bright blue star at the center of this image is a B-type supergiant named Kappa Cassiopeiae, 4,000 light-years away. As stars in our galaxy go it’s pretty big — over 57 million kilometers wide, about 41 times the radius of the Sun. But its size isn’t what makes K Cas stand out — it’s the infrared-bright bow shock it’s creating as it speeds past its stellar neighbors at a breakneck 1,100 kilometers per second.

K Cas is what’s called a runway star. It’s traveling very fast in relation to the stars around it, possibly due to the supernova explosion of a previous nearby stellar neighbor or companion, or perhaps kicked into high gear during a close encounter with a massive object like a black hole.

As it speeds through the galaxy it creates a curved bow shock in front of it, like water rising up in front of the bow of a ship. This is the ionized glow of interstellar material compressed and heated by K Cas’ stellar wind. Although it looks like it surrounds the star pretty closely in the image above, the glowing shockwave is actually about 4 light-years out from K Cas… slightly less than the distance from the Sun to Proxima Centauri.

The bow shock of Zeta Ophiuchi, another runaway star observed by Spitzer (NASA/JPL-Caltech)
The bow shock of Zeta Ophiuchi, another runaway star observed by Spitzer (NASA/JPL-Caltech)

Although K Cas is visible to the naked eye, its bow shock isn’t. It’s only made apparent in infrared wavelengths, which NASA’s Spitzer Space Telescope is specifically designed to detect. Some other runaway stars have brighter bow shocks — like Zeta Ophiuchi at right — which can be seen in optical wavelengths (as long as they’re not obscured by dust, which Zeta Oph is.)

Related: Surprise! IBEX Finds No Bow ‘Shock’ Outside our Solar System

The bright wisps seen crossing K Cas’ bow shock may be magnetic filaments that run throughout the galaxy, made visible through interaction with the ionized gas. In fact bow shocks are of particular interest to astronomers precisely because they help reveal otherwise invisible features and allow deeper investigation into the chemical composition of stars and the regions of the galaxy they are traveling through. Like a speeding car on a dark country road, runaway stars’ bow shocks are — to scientists — like high-beam headlamps lighting up the space ahead.

Runaway stars are not to be confused with rogue stars, which, although also feel the need for speed, have been flung completely out of their home galaxies.

Source: NASA

Posted on by Elizabeth Howell

After A Long Nap, NEOWISE Springs Into Action With Asteroid Discoveries

Dots (circled) in this image show the first asteroid spotted by NASA's Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) after the mission came out of hibernation. Credit: NASA

If anything, NASA’s asteroid-hunting spacecraft seems to be refreshed after going into forced hibernation for 2.5 years. In the first 25 days since it started seeking small solar system bodies in earnest again, the Near-Earth Object Wide-field Infrared Survey Explorer (NEOWISE) found three new objects and detected an additional 854, NASA said Thursday (Jan. 23).

Luckily for people interested in this field, Amy Mainzer (the principal investigator for this mission) has been tweeting out discoveries as they come — and other observations besides. “Just passed our @WISE_Mission post-restart review. I believe the technical term is “Yee haw!!” she wrote Jan. 21. Below are a couple of illustrated examples of discoveries from her Twitter feed. Click on the pictures for larger versions.

2014 AA53 NEOWISE

2014 AQ46 NEOWISE

In a release, NASA added that NEOWISE is “observing and characterizing” one NEO a day, which means not only looking at the object, but probing its size and composition. Astronomers know of about 10,500 NEOs, but of those only 10% (or about 1,500) have physical measurements cataloged as well. NEOWISE investigators aim to make hundreds of more of these measurements.

The mission (originally called WISE) launched in December 2009 to examine the universe in infrared light. After completely mapping the sky, it ran out of coolant it needed to do this work in 2010. It then shifted to examining comets and asteroids before being put into hibernation in February 2011. Read more about its mission history in this past Universe Today article.

Posted on by Tammy Plotner

Argon – The First Noble Gas Molecules Discovered In Space

Messier 1 Hubble Image: Credit - NASA, ESA, J. Hester and A. Loll (Arizona State University)

There are only six of them: radon, helium, neon, krypton, xenon and the first molecules to be discovered in space – argon. They are all odorless, colorless, monatomic gases with very low chemical reactivity. So where did a team of astronomers using ESA’s Herschel Space Observatory make their rather unusual discovery? Try Messier 1… The “Crab” Nebula!

In a study led by Professor Mike Barlow (UCL Department of Physics & Astronomy), a UCL research team was taking measurements of cold gas and dust regions of this famous supernova remnant in infrared light when they stumbled upon the chemical signature of argon hydrogen ions. By observing in longer wavelengths of light than can be detected by the human eye, the scientists gave credence to current theories of how argon occurs naturally.

“We were doing a survey of the dust in several bright supernova remnants using Herschel, one of which was the Crab Nebula. Discovering argon hydride ions here was unexpected because you don’t expect an atom like argon, a noble gas, to form molecules, and you wouldn’t expect to find them in the harsh environment of a supernova remnant,” said Barlow.

When it comes to a star, they are hot and ignite the visible spectrum. Cold objects like nebular dust are better seen in infrared, but there’s only one problem – Earth’s atmosphere interferes with the detection of that end of the electromagnetic spectrum. Even though we can see nebulae in visible light, what shows is the product of hot, excited gases, not the cold and dusty regions. These invisible regions are the specialty of Herschel’s SPIRE instruments. They map the dust in far-infrared with their spectroscopic observations. In this instance, the researchers were somewhat astounded when they found some very unusual data which required time to fully understand.

“Looking at infrared spectra is useful as it gives us the signatures of molecules, in particular their rotational signatures,” Barlow said. “Where you have, for instance, two atoms joined together, they rotate around their shared center of mass. The speed at which they can spin comes out at very specific, quantized, frequencies, which we can detect in the form of infrared light with our telescope.”

According to the news release, elements can exist in varying forms known as isotopes. These have different numbers of neutrons in the atomic nuclei. When it comes to properties, isotopes can be somewhat alike to each other, but they have different masses. Because of this, the rotational speed is dependent on which isotopes are present in a molecule. “The light coming from certain regions of the Crab Nebula showed extremely strong and unexplained peaks in intensity around 618 gigahertz and 1235 GHz.” By comparing data of known properties of different molecules, the science team came to the conclusion the mystery emission was the product of spinning molecular ions of argon hydride. What’s more, it could be isolated. The only argon isotope which could spin like that was argon-36! It would appear the energy released from the central neutron star in the Crab Nebula ionized the argon, which then combined with hydrogen molecules to form the molecular ion ArH+.

Professor Bruce Swinyard (UCL Department of Physics & Astronomy and Rutherford Appleton Laboratory), a member of the team, added: “Our discovery was unexpected in another way — because normally when you find a new molecule in space, its signature is weak and you have to work hard to find it. In this case it just jumped out of our spectra.”

Is this instance of argon-36 in a supernova remnant natural? You bet. Even though the discovery was the first of its kind, it is doubtless not the last time it will be detected. Now astronomers can solidify their theories of how argon forms. Current predictions allow for argon-36 and no argon-40 to also be part of supernova structure. However, here on Earth, argon-40 is a dominant isotope, one which is created through the radioactive decay of potassium in rocks.

Noble gas research will continue to be a focus of scientists at UCL. As an amazing coincidence, argon, along with other noble gases, was discovered at UCL by William Ramsay at the end of the 19th century! I wonder what he would have thought had he known just how very far those discoveries would take us?

Original Story Source: University College London (UCL) Press Release

Posted on by Tammy Plotner

Subaru Telescope Reveals Orderly Massive Galaxy Evolution

FMOS spectra in the J-band (left panel) and H-band (right panel), each of which filters light so that only specific wavelengths can pass through. The horizontal axis refers to the wavelength direction while the vertical axis indicates individual spectra observed through each fiber. Small blue circles indicate the detection of emission lines (left: H? and [OIII]; right: H?, [NII]). The inset box shows the intensity of the emission lines for one galaxy. The vertical bands indicate the masked regions where bright sky (OH) emissions are prevented from entering science fibers placed on high-redshift galaxies. (Credit: FMOS-COSMOS)

Nobody likes a sloppy COSMOS (Cosmological Evolution Survey) and astronomers utilizing the Fiber-Multi-Object Spectrograph (FMOS) mounted on the Subaru Telescope have put order into chaos through their studies. The survey has found that some nine billion years ago galaxies were capable of producing new stars in a fashion as orderly as game of checkers. Despite their young cosmological age, the galaxies show signs containing high amounts of dust enriched by heavier elements – a mature state.

“These findings center on a major question: What was the universe like when it was maximally forming its stars?” says John Silverman, the principal investigator of the FMOS-COSMOS project at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU).

These “universal” questions are just what the COSMOS team seeks to answer. Their research goals are to enlighten the scales of cosmic time in relationship with the environment, formation and evolution of massive galactic structures. When studying individual galaxies, they may be able to tell if their rate of growth can be attributed to large-scale environments. Information of this type can clarify what factors the early Universe structure may have contributed to the current form of local galaxies. One of the data sets the team is focusing on is using the FMOS on the Subaru Telescope to chart out the distribution of more than a thousand galaxies which formed over nine billion years ago – a time when the Universe was hitting its star-formation peak.

“One key to generating fruitful results is collaboration between COSMOS researchers to maximize optimal use of FMOS.” Silverman continues, “In this project, researchers from Kavli IPMU in Japan and the Institute for Astronomy at the University of Hawaii (principal investigator: David Sanders) formed an effective collaboration to implement their goal.” The observations spanned 10 clear nights starting in March 2012.

Why choose spectroscopy? This advanced fiber optics technology speaks for itself, collecting light over an area of sky equal in size to that of the Moon. The FMOS focuses on the near-infrared, filtering out unwanted emissions caused by warm temperatures and can acquire spectra from 400 galaxies simultaneously with a wide field of coverage of 30 arc minutes at prime-focus. By employing such a wide field of view, astronomers can squeeze in a wide range of objects in their local environments. This enables researchers to maximize information on star-forming regions, cluster formation, and cosmology.

As David Sanders, the principal investigator of the FMOS-COSMOS project at IfA, puts it, “FMOS has clearly revolutionized our ability to study how galaxies form and evolve across cosmic time. It is currently the most powerful instrument we have to study the large numbers of objects needed to understand galaxies of all sizes, shapes and masses — from the largest ellipticals to the smallest dwarfs. We are extremely fortunate that the Kavli IPMU-IfA collaboration is giving us this unique opportunity to study the distant universe in such exquisite detail.”

FMOS will soon be famous by revealing its true potential. It has been collecting copious amounts of data in a high spectral resolution mode and at a very successful rate. So far it has accomplished nearly half of its goal – to examine over a thousand galaxies with redshifts to map the large-scale structure. The current survey consists of mapping an area of sky which spans a square degree in high-resolution mode and future plans for FMOS will involve enlarging the area. This expanded coverage will complement other instruments on alternative telescopes which have a wider spectral imaging system or a higher resolution which is limited to a smaller area. These combined findings may one day result in showing us some of the very first structures that eventually evolved into the massive galaxy clusters we see today!

Original Story Source: Kavli Institute for the Physics and Mathematics of the Universe News Release.

Posted on by Tammy Plotner

Exploring Our Galaxy’s Ancient Brown Dwarfs

A brown dwarf from the thick-disk or halo is shown. Although astronomers observe these objects as they pass near to the solar system, they spend much of their time away from the busiest part of the Galaxy, and the Milky Way's disk can be seen in the background. Credit: John Pinfield

As the name implies, a brown dwarf is small… only about 7% the size of the Sun. As far as stellar senior citizens go, they’re cool. Zipping along through space at speeds of 100 to 200 kilometers per second, they may have formed back when our galaxy was young – perhaps 10 billion years ago. Now a team of astronomers headed by Dr. David Pinfield at the University of Hertfordshire has identified a pair of the oldest brown dwarfs known… a set of orbs which could be the harbinger of a huge amount of new, unseen objects.

Although we sometimes refer to them as stars, brown dwarfs are in a class of their own. Because they didn’t ignite in nuclear fusion, they don’t generate internal heat like an ordinary star. After they are formed, they continue to cool and fade as time passes. This process makes them very difficult to observe and the discovery of two very old brown dwarfs, with temperatures of 250-600 C is cause for astronomical excitement.

Just how did Pinfield’s team pick such tiny objects out of the vastness of space? The discovery was facilitated thanks to a survey made by the Wide-field Infrared Survey Explorer (WISE), a NASA observatory that scanned the mid-infrared sky from orbit in 2010 and 2011. The ancient objects are cataloged as WISE 0013+0634 and WISE 0833+0052, and they are located in the constellations of Pisces and Hydra. Because they are so elusive, they were also confirmed by large ground-based telescopes (Magellan, Gemini, VISTA and UKIRT).

However, identifying the pair wasn’t easy. Seeing through the eyes of infrared reveals a crowded space – one populated with reddened stars, distant background galaxies and pockets of nebulous gas and dust. Picking out such a small character from a stellar cast would be like finding one tiny pearl in the vastness of an ocean. But Pinfield’s researchers employed a new method which utilizes WISE’s capabilities. As it scanned the sky over and over again, it revealed the cool, brown dwarfs – picking up the faint signature that other searches had missed.

These two particular brown dwarfs are different from the other slow movers of their type. By studying their spectra, the astronomers have identified atmospheres almost entirely comprised of hydrogen. This sets them apart from younger stars which have an abundance of heavier elements. Does being lighter make them speedier? According to Pinfield, “Unlike in other walks of life, the galaxy’s oldest members move much faster than its younger population.”

Stars near to Sun are considered the “local volume” and are created with three overlapping populations – the thin disk, the thick disk and the halo. Each of these layers has a certain amount of age associated with it: the oldest being the thickest and its member stars move up and down at a higher rate of speed. The halo contains both disks, along with the initial materials which formed the very first stars. Thin disk objects abound in the local volume and account for about 97% of the local stars, while thick disk and halo objects are a meager 3%. Chances are, brown dwarfs belong to that smaller percentage which explains why these fast-moving thick-disk/halo objects are only now being revealed.

Just how many may await discovery? Scientists surmise there may be as many as 70 billion brown dwarfs in the galaxy’s thin disk, and the thick disk and halo take up significantly larger galactic volumes. Even at a tiny 3%, this means there could be an army of ancient brown dwarfs in the galaxy. “These two brown dwarfs may be the tip of an iceberg and are an intriguing piece of astronomical archaeology,” said Pinfield. “We have only been able to find these objects by searching for the faintest and coolest things possible with WISE. And by finding more of them we will gain insight into the earliest epoch of the history of the galaxy.”

Original Story Source: Royal Astronomical Society News Release. For further study: “A deep WISE search for very late type objects and the discovery of two halo/thick-disk T dwarfs: WISE 0013+0634 and WISE 0833+0052”, D. J. Pinfield et al, Monthly Notices of the Royal Astronomical Society, in press.

Posted on by Matthew Francis

Taking Measure: A ‘New’ Most Distant Galaxy

Galaxy z8_GND_5296 (seen in the inset) is the earliest galaxy that astronomers have measured the distance to accurately. It formed approximately 700 million years after the Big Bang, and is forming stars at an incredibly rapid rate. [Credit: V. Tilvi (Texas A&M), S. Finkelstein (UT Austin), the CANDELS team, and HST/NASA]

“The farthest galaxy yet seen!” Haven’t we heard that one before? (See here and here, for example.) While it’s true that astronomers keep pushing farther back in time with better instruments, there are fundamental challenges both in observing and measuring the distances to the earliest galaxies in the cosmos.

That’s why this new observation of a galaxy that formed about 700 million years after the Big Bang is significant. While scores of galaxies have been identified that formed in that era, astronomers have only measured accurate distances for five of them. This galaxy marks the sixth, and it is the farthest of the bunch. Perhaps even more important than the distance measurement, researchers determined that this galaxy gave birth to new stars at more than 100 times the rate the Milky Way does today. That indicates early galaxies may have been more aggressive with star-formation than previously believed. Continue reading “Taking Measure: A ‘New’ Most Distant Galaxy”

Posted on by Tammy Plotner

New Camera Aboard APEX Gets First Light

This image of the star formation region NGC 6334 is one of the first scientific images from the ArTeMiS instrument on APEX. The picture shows the glow detected at a wavelength of 0.35 millimetres coming from dense clouds of interstellar dust grains. The new observations from ArTeMiS show up in orange and have been superimposed on a view of the same region taken in near-infrared light by ESO’s VISTA telescope at Paranal. Credit: ArTeMiS team/Ph. André, M. Hennemann, V. Revéret et al./ESO/J. Emerson/VISTA Acknowledgment: Cambridge Astronomical Survey Unit

And the “Cat’s Paw” was waiting to strike! In this exceptionally detailed image of star-forming region NGC 6334 we can get a sense of just how important new instrumentation can be. In this case it’s a new camera called ArTeMiS and it has just been installed on a 12-meter diameter telescope located high in the Atacama Desert. The Atacama Pathfinder Experiment – or APEX for short – operates at millimeter and submillimeter wavelengths, providing us with observations ranging between radio wavelengths and infrared light. These images give astronomers powerful new data to help them further understand the construction of the Universe.

Exactly what is ArTeMiS? The camera provides wide field views at submillimeter wavelengths. When added to APEX’s arsenal, it will substantially increase the amount of details a particular object has to offer. It has a detector array similar to a CCD camera – a new technology which will enable it to create wide-field maps of target areas with a greater amount of speed and a larger amount of pixels.

Like almost all new telescope projects, both personal and professional, the APEX team met up with “first light” problems. Although the ArTeMiS Camera was ready to go, the weather simply wouldn’t cooperate. According to the news release, very heavy snow on the Chajnantor Plateau had almost buried the building in which the scope operations are housed! However, the team was determined. Using a makeshift road and dodging snow drifts, the team and the staff at the ALMA Operations Support Facility and APEX somehow managed to get the camera to its location safely. Undaunted, they installed the ArTeMiS camera, worked the cryostat into position and locked the instrumentation down in its final position.

However, digging their way out of the snow wasn’t all the team had to contend with. To get ArTeMis on-line, they then had to wait for very dry weather since submillimeter wavelengths of light are highly absorbed by atmospheric moisture. Do good things come to those who wait? You bet. When the “magic moment” arrived, the APEX team was ready and the initial test observations were a resounding success. ArTeMiS quickly became the focus tool for a variety of scientific projects and commissioned observations. One of these projects was to image star-forming region NGC 6334 – the Cat’s Paw Nebula – in the southern constellation of Scorpius. Thanks to the new technology, the ArTeMiS image shows a superior amount of detail over earlier photographic observations taken with APEX.

What’s next for ArTeMiS? Now that the camera has been tested, it will be returned to Saclay in France to have even more detectors installed. According to the researchers: ” The whole team is already very excited by the results from these initial observations, which are a wonderful reward for many years of hard work and could not have been achieved without the help and support of the APEX staff.”

Original Story Source: ESO Public News Release.

Posted on by Jason Major

“Oddball” Asteroid is Really a Comet

Spitzer image of an asteroid's surprise coma and tail (NASA/JPL-Caltech/DLR/NAU)

It’s a case of mistaken identity: a near-Earth asteroid with a peculiar orbit turns out not to be an asteroid at all, but a comet… and not some Sun-dried burnt-out briquette either but an actual active comet containing rock and dust as well as CO2 and water ice. The discovery not only realizes the true nature of one particular NEO but could also shed new light on the origins of water here on Earth.

JPL Near-Earth Object database map of 3552 Don Quixote's orbit
JPL Near-Earth Object database map of 3552 Don Quixote’s orbit

Designated 3552 Don Quixote, the 19-km-wide object is the third largest near-Earth object — mostly rocky asteroids that orbit the Sun in the vicinity of Earth.

According to the IAU, an asteroid is coined a near-Earth object (NEO) when its trajectory brings it within 1.3 AU from the Sun and within 0.3 AU of Earth’s orbit.

About 5 percent of near-Earth asteroids are thought to actually be dead comets. Today an international team including Joshua Emery, assistant professor of earth and planetary sciences at the University of Tennessee, have announced that Don Quixote is neither.

an asteroid is coined a Near Earth Asteroid (NEA) when its trajectory brings it within 1.3 AU from the Sun and hence within 0.3 AU of the Earth's orbit.
An asteroid is coined a near-Earth object (NEO) when its trajectory brings it within 1.3 AU from the Sun and within 0.3 AU of Earth’s orbit. (IAU)

“Don Quixote has always been recognized as an oddball,” said Emery. “Its orbit brings it close to Earth, but also takes it way out past Jupiter. Such a vast orbit is similar to a comet’s, not an asteroid’s, which tend to be more circular — so people thought it was one that had shed all its ice deposits.”

Read more: 3552 Don Quixote… Leaving Our Solar System?

Using the NASA/JPL Spitzer Space Telescope, the team — led by Michael Mommert of Northern Arizona University — reexamined images of Don Quixote from 2009 when it was at perihelion and found it had a coma and a faint tail.

Emery also reexamined images from 2004, when Quixote was at its farthest distance from the Sun, and determined that the surface is composed of silicate dust, which is similar to comet dust. He also determined that Don Quixote did not have a coma or tail at this distance, which is common for comets because they need the sun’s radiation to form the coma and the sun’s charged particles to form the tail.

The researchers also confirmed Don Quixote’s size and the low, comet-like reflectivity of its surface.

“The power of the Spitzer telescope allowed us to spot the coma and tail, which was not possible using optical telescopes on the ground,” said Emery. “We now think this body contains a lot of ice, including carbon dioxide and/or carbon monoxide ice, rather than just being rocky.”

This discovery implies that carbon dioxide and water ice might be present within other near-Earth asteroids and may also have implications for the origins of water on Earth, as comets are thought to be the source of at least some of it.

The amount of water on Don Quixote is estimated to be about 100 billion tons — roughly the same amount in Lake Tahoe.

“Our observations clearly show the presence of a coma and a tail which we identify as molecular line emission from CO2 and thermal emission from dust. Our discovery indicates that more NEOs may harbor volatiles than previously expected.”

– Mommert et al., “Cometary Activity in Near–Earth Asteroid (3552) Don Quixote “

The findings were presented Sept. 10 at the European Planetary Science Congress 2013 in London.

Source: University of Tennessee press release

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3552 Quixote isn’t the only asteroid found to exhibit comet-like behavior either — check out Elizabeth Howell’s recent article, “Asteroid vs. Comet: What the Heck is 3200 Phaethon?” for a look at another NEA with cometary aspirations.

Posted on by Tammy Plotner

Hubble Looks Back In Time To See Shape Of Galaxies 11 Billion Years Ago

This image shows "slices" of the Universe at different times throughout its history (present day, and at 4 and 11 billion years ago). Each slice goes further back in time, showing how galaxies of each type appear. The shape is that of the Hubble tuning fork diagram, which describes and separates galaxies according to their morphology. Credit: NASA, ESA, M. Kornmesser

What we’re gonna’ do here is go back. Way back into time. Back to when the only thing that existed was… galaxies? When astronomers employed the power of Hubble’s CANDELS survey to observe different galaxy types from the distant past, they expected to see a variety of spiral, elliptical, lenticular and peculiar structures, but what they didn’t expect was that things were a whole lot more “peculiar” a long time ago!

Known as the Hubble Sequence, astronomers use this classified system for listing galaxy sizes, shapes and colors. It also arranges galaxies according to their morphology and star-forming activity. Up to the present, the Hubble Sequence covered about 80% of the Universe’s history, but the latest information shows that the sequence was valid as much as 11 billion years ago! Out of what we currently know, there are two dominant galaxy types – spiral and elliptical – with the lenticular structure as a median. Of course, this is constrained to the regions of space which we can readily observe, but how true did the sequence hold back when the Universe theoretically began?

“This is a key question: when and over what timescale did the Hubble Sequence form?” says BoMee Lee of the University of Massachusetts, USA, lead author of a new paper exploring the sequence. “To do this you need to peer at distant galaxies and compare them to their closer relatives, to see if they too can be described in the same way.”

Using the Hubble Space Telescope, astronomers took on the sequence challenge to peer back 11 billion years in time to study galaxy structure. Up until now, researchers could confirm the sequence was valid as long ago as 8 billion years, but these new studies pushed CANDELS, the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, to the outer limits. It is simply the largest project ever, and soaked up 902 assigned orbits of observing time. Using the WFC3 and ACS cameras, the team examined structures that existed less than one billion years after the Big Bang. While earlier studies had aimed for lower-mass galaxies in this era, no study had really taken on serious observation of mature structures – ones similar to our own galaxy. Now the new CANDELS observations show us that all galaxies, regardless of size, fit into a totally different classification!

“This is the only comprehensive study to date of the visual appearance of the large, massive galaxies that existed so far back in time,” says co-author Arjen van der Wel of the Max Planck Institute for Astronomy in Heidelberg, Germany. “The galaxies look remarkably mature, which is not predicted by galaxy formation models to be the case that early on in the history of the Universe.”

Just what did this study see that’s so different? Just the power of two. Galaxies were either complex, with blue star forming regions and irregular structures, or they were like our nearby neighbors: massive red galaxies that exhibit no new star-formation. In the early Universe, galaxies like the Milky Way were uncommon. With so little to study, it was nearly impossible to get a large enough sample to sufficiently catalog their characteristics. Early research could only peer back in visible light, a format which emphasized star formation and revealed the red-shifted ultraviolet emission of the galaxies. This information was inconclusive because galaxy structure appeared disrupted and unlike the formations we see near to us. Through the use of infra-red, astronomers could observe the now red-shifted massive galaxies in their visible rest frame. Thanks to CANDELS lighting the way, astronomers were able to thoroughly sample a significantly larger amount of mature galaxies in detail.

“The huge CANDELS dataset was a great resource for us to use in order to consistently study ancient galaxies in the early Universe,” concludes Lee. “And the resolution and sensitivity of Hubble’s WFC3 is second to none in the infrared wavelengths needed to carry out this study. The Hubble Sequence underpins a lot of what we know about how galaxies form and evolve — finding it to be in place this far back is a significant discovery.”

Original Story Source: ” Hubble Explores the Origins of Modern Galaxies” – Hubble News Release.

Posted on by Elizabeth Howell

Rocky Alien Planets: What The Heck Is On Their Surfaces?

NASA's Kepler mission confirmed the discovery of its first rocky planet, named Kepler-10b. Measuring 1.4 times the size of Earth, it is the smallest planet ever discovered outside our solar system.

We don’t have the budget yet to send Star Trek‘s U.S.S. Enterprise to probe the surface of strange new worlds, but luckily for humanity, astronomers are figuring out techniques to do that without even needing to leave Earth.

One of Earth’s prolific planet-hunters, the Kepler Space Telescope, has found a lot of planet candidates with rocky surfaces. That’s exciting for astronomers, as rocky planets tend to be smaller than their gas giant counterparts. Also, learning more about rocky planets could give us more clues as to Earth’s history, and that of other planets in our solar system.

But how the heck, from so far away, can we begin to understand the surface? One idea: Check the heat signature, or in more scientific words, look at exoplanets in the infrared part of the light spectrum.

The visible colors, infrared, radio, X-rays and gamma rays are all forms of light and comprise the electromagnetic spectrum. Here you can compare their wavelengths with familiar objects and see how their frequencies (bottom numbers) increase with decreasing wavelength. Credit: ESA
The visible colors, infrared, radio, X-rays and gamma rays are all forms of light and comprise the electromagnetic spectrum. Here you can compare their wavelengths with familiar objects and see how their frequencies (bottom numbers) increase with decreasing wavelength. Credit: ESA

NASA’s Astrobiology Magazine recently published an article about this method, which we encourage you to check out. In summary, the team behind a new research paper (submitted to the Astrophysical Journal) proposes to check out “airless” exoplanets that have surface temperatures below 3,140 degrees Fahrenheit (1,726 Celsius or 2,000 Kelvin.)

Because different kinds of rocks emit “signature” spectrums in different wavelengths, it’s possible we could pick up the signs of silicate rocks or other types of material. There’s a caveat, though.

“With current technology, however, the team cautions that determining surface composition of exoplanets is a very different process than studying their solar system counterparts,” the magazine wrote. “Due to the limits of technology, the team proposes to concentrate on the most prominent mineral signatures detected from exoplanets.”

Check out more details in the scientific journal article here, or the entire Astrobiology Magazine article at this link.