Astronomy Photo of the Day: 12/18/13 - The Circinus Galaxy

Chandra - along with ESO"s Very Large Telescope Array - spied a bright, variable supernova blast located in a galaxy 12 million light-years away. This image is a composite showing the central region of the galaxy in question, which is typically referred to as the Circinus galaxy.

In the lower right hand corner of the image, the blue source of light is the supernova blast itself (designated "SN 1996cr"). It was originally discovered back in 2001 (though the light from the actual explosion arrived more than a decade before it was even discovered). Despite there being so many stars in the night sky, it"s pretty infrequent that we observe these celestial events in independent galaxies. By some estimations, one should expect to see one supernova explosion once every 50 years per galaxy! The last verified explosion in the Milky Way was observed back in 1604 by the famed astronomer, Johannes Kepler (many other contenders have been noted in recent years though).

Furthermore, some of you may recall the famous supernova SN 1987A, which occurred in a galaxy approximately 160,000 light-years away -- It"s quite similar to supernova SN 1996cr in many ways, but SN 1996cr spits out almost 1000 times more radio and x-ray emissions.

References & Additional Reading: http://www.fromquarkstoquasars.com/astronomy-photo-of-the-day-121813-the-circinus-galaxy/

Image Credit: X-ray (NASA/CXC/Columbia/F.Bauer et al); Optical (NASA/STScI/ UMD/A.Wilson et al.)

Astronomy Picture of the Day: 12/16/13 - The Pinwheel Galaxy

The Pinwheel Galaxy, which can be found more than 21 million light-years from Earth in the constellation of Ursa Major, is one of the most majestic galaxies in the observable universe. The only thing more impressive than the galaxy"s beauty is its size. It comes in with a staggering diameter of 170,000 light-years, making it about 70% larger than our home galaxy, the Milky Way (it, in contrast, is about 100,000 light-years across).

You may not know this, but capturing a detailed image of distant galaxies isn"t as easy as clicking a button on a camera. For instance, take the beautiful photograph of the Pinwheel Galaxy seen here. Instead of it being one shot, it"s actually a composite of four shots taken in infrared, visible light, ultraviolet and x-ray. Optical data was collected by the Hubble Space Telescope (in yellow). The Chandra X-ray Observatory captured the galaxy at x-ray wavelengths (seen in purple), while the Spitzer Space Telescope viewed it at infrared wavelengths (seen in red). Ultraviolet data was taken by GALEX - the Galaxy Evolution Explorer - in blue.

Sources & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-121613-the-pinwheel-galaxy/

Image Credit: Chandra X-ray Observatory, Spitzer Satellite, Hubble Space Telescope, and GALEX Satellite