Sometimes, what you think is the darkest thing you've ever seen really isn't that dark at all. Case in point: the gegenschein. No, it's not something you say after someone sneezes, though it does have something to do with particles of dust.  Find out more about the gegenschein in the full article after the jump.

  

Galaxy Messier 81 is a spiral galaxy, much like our very own Milky Way, located 11.6 million light years away. The Hubble Space Telescope of NASA recently took high resolution image captures of M81. And through a series of collaborating space observatories around the globe, they were able to collect new information regarding the mysterious galaxy not very dissimilar from our own.

"The view we have of M81 is similar to what an astronomer in Andromeda would see if they looked at the Milky Way," explained Andreas Zezas of the Harvard-Smithsonian Center for Astrophysics. It's also surprising that the Hubble, named after Edwin Hubble who first discerned that the stars in Andromeda marked the galaxy distinct from our own, repeated such a feat 80 years after, with a galaxy five times farther away.

 

If fact, NASA pegs M81 as one of the brightest galaxies that can be viewed from Earth. With a penchant for discerning colors and lights, star gazers could find the Milky Way look-alike high up in the northern sky close to the constellation Ursa Major, the Great Bear. It's obliquely angled to the Milky Way, so much of the galaxy is viewable.

Click on Full Article to get a more detailed image of the galaxy and find out more of M81.

It looks like CES wasn't the only big thing happening this early in the year. The 209th meeting of the Astronomical Society of America also occurred last week, and one of the big presentations of the meeting was an assertion about one of our neighboring galaxies. According to the findings, it seems as if the Andromeda galaxy is five times larger than people thought.

Without getting too scientific, first imagine that a galaxy is made up of three parts, as our source notes: "a flattened disk, a bright central bulge of densely packed stars, and an extended spherical halo where stars are more sparsely distributed." The stars in the halo are supposed to be the first stars that form in the galaxy, and current theories of galaxy formation state that the halo stars should have less heavy metal content on them compared to the stars closer to the galaxy's center.

Now, our galaxy and the Andromeda galaxy are supposed to have similar rates of galaxy formation. This should mean that the halo stars of Andromeda ought to have a similar amount of heavy metal content. Researchers who've previously seen Andromeda's halo stars, however, noted that they're 10 times richer in metals than our own halo stars. In astronomical terms, that's a pretty big discrepancy.

What members of the study team found were some new stars farther away from Andromeda's center. These new red giant stars weren't seen before, and may explain why the halo stars were so metal rich: because they weren't the actual edge of the Andromeda galaxy and, therefore, not actual halo stars. As the picture above shows, this means that an even larger portion of our night sky may actually be part of another galaxy.

Better still, it gives us an even better reason to look up at the night sky.

European scientists announced today the discovery of two Jupiter-sized planets orbiting stars in the constellations of Andromeda and Delphinus.  These are some of the hottest planets ever discovered. Radiation from parent stars is causing them to lose their atmospheres. These were the first planets to be discovered by the U.K.'s SuperWASP (Wide Angle Search for Planets), which uses wide angle camera lenses that can detect variations in starlight caused by planetary transit.  The findings were confirmed by French scientists, working with their own high-powered instruments.

What is unique about this discovery is the fact that SuperWASP's telescopes are capable of looking at millions of stars at a time. Previously, the discovery of extra-solar planets required the painstaking observations of individual stars, using very expensive telescopes.  So far, 200 of these planets outside our own solar system have been found.  SuperWASP consists of a number of smaller telescopes that work with highly sensitive, high-tech cameras that can make observations of broad areas of the sky, capable of generating 60 gigabytes of data in one night.

These most recent discoveries are known as "hot Jupiters" - so-called because they are gas giants that orbit very close to their parent stars.  These discoveries come on the eve of the launching of a new 35-million Euro (about 40 million USD) satellite that will facilitate the observation of extra-solar planets. Between SuperWASP and the COROT Satellite,  discoveries of extra-solar planets should increase substantially, allowing astronomers to better understand planetary formation.

Scientists have discovered an enormous amoeba-like structure 200 million-light years wide and made up of galaxies and large bubbles of gas; they now think is the largest known object in the universe. How big is it really?

Let's just say that the galaxies that they have found in the composition of the blob is packed four times closer than the universe's average. And the gas bubbles found inside it are 400,000 light years across. That is twice the diameter of the Andromeda Galaxy. One of the existing theories about these bubbles is that they will one day give birth to new galaxies.

"Something this large and this dense would have been rare in the early universe," said study team member Ryosuke Yamauchi from Tohoku University. It is aligned along three curvy filaments that is believed to have came into existence after the theoretical Big Bang.

"The structure we discovered and others like are probably the precursors of the largest structures we see today which contain multiple clusters of galaxies," Yamauchi said.

This picture of the Milky Way's other sister galaxy, the Triangulum galaxy or M33, was taken by the MMT Observatory's 6.5-meter 340-megapixel telescope in MMT's attempt to show just how powerful this megacam instrument is.

What better way to show its power than to take a picture of this very attractive galaxy 2.4 million light years away from Earth. You might have expected another image of the Andromeda galaxy, but it's high time the Triangulum galaxy gets more attention. After all, with this photo taken by the Megacam, it shows just how beautiful the galaxy is (even from afar).

The image taken shows Triangulum's eye-catching swirls of stars and dust dotted with brilliant pink nebulae - all thanks to the Smithsonian Astrophysical Observatory-developed Megacam instrument. This camera contains nine million picture elements (pixels) in each of the 36 CCD chips in the camera, making it the largest digicam in the world.

The M33 (Messier 33 or Triangulum galaxy) has pink filaments of hydrogen gas marking regions of active star formation that's very similar to the Orion Nebula of the Milky Way. Looking at the image, the nebula at the upper left spans 1,500 light-years and holds more than 200 hot young stars.

This image is the first image taken by the MMT telescope which will have its "eye" set on continuing to explore space.

The galaxy known as Andromeda is situated some 2.5 million light-years from our location, riding like a majestic counterweight to the Milky Way (which it is believed to resemble) on the other end of the Local Group.

This spectacular infra-red photo was taken by the Spitzer Space Telescope, a composite of over 3,000 individual frames. In this image, interstellar gas appears red, while older stars show up in blue. Young stars located in the galaxy's spiral arms are clear in the visible light spectrum, but when the infra-red filter is added, trails of dust lead back toward the core.

The purpose behind this image was to  explore Andromeda's infra-red brightness and determine the nature of its stellar population. Although as a "spiral"-type galaxy, Andromeda - with around one trillion stars - is well over twice the size of the Milky Way.

Images of Andromeda taken with NASA's Spitzer and Chandra Space Telescopes at the Gemini North Observatory in Hawaii are giving scientists a whole new view of the Milky Way's closest neighbor. The latest pictures reveal details about Andromeda's central bulge and inner disk as well as its very heart. 

Researchers put together more than 3,000 separate infrared images taken with Spitzer to create a series of mosaic images that separated Andromeda's old stars (which resembled smooth, soft blue smudge) from the thick veil of dust and gas (which appered as concentric rings of fire) covering it. Based on the mosaic, researchers estimated the total amount of infrared light emitted by Andromeda is equal to 4 billion suns.

Since the amount of light a star gives off depends on its mass, researchers calculated the total mass of all the stars in Andromeda is equal to about 110 billion suns. That's not counting the small red dwarfs that are less massive than the sun. Adding them to the equation would boost the number to about a trillion stars.

The new data also allowed the team to estimate the number of new stars born in Andromeda each year. The star population growth over there was pegged at about 0.6 solar masses per year on average - an unxpectedly low figure than most scientists anticipated. The more fertile Milky Way is calculated to produce about half a dozen baby stars every year.

Meanwhile, the Chandra Space Telescope team, led by Knut Olsen, presented the deepest and highest resolution images taken of Andromeda's central bulge and inner disk. The images show thousands of individual stars within 6,500 light-years of the galaxy’s nucleus.

According to the team's researches, most of those stars are relatively old and have heavy-element compositions similar to our Sun. This means Andromeda’s inner disk could be at least 6 billion years old (the universe itself is thought to have celebrated more than 13 billion birthdays).

New images taken by Chandra X-ray telescope revealed a collection of point-like sources within a diffuse, X-ray emitting cloud of hot gas. What heats the gas, scientists say, could be the shockwaves produced during supernova explosions. As matter falls towards the neutron star or black hole, it is heated by friction to tens of millions of degrees until it emits X-rays.