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: 11/18/18 - R Coronae Australis Complex

This image was taken by the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile of a region located approximately 420 light-years" distance (in the constellation of Corona Australis).

The region, formally known as R Coronae Australis Complex (named after R Coronae Australis, the star located in the center of the image), is one of the closest and most spectacular star formation regions in our galaxy. The blue areas are a result of starlight reflecting from the dust particles that comprise portions of the nebula. The dark areas, however, are a product of a similar mechanism, but instead of the starlight reflecting from the dust particles, it is absorbed, making them impenetrable to visible light.

Over all, the region covers a full 33.7 x 31.9 arc-minutes (approximately the diameter of the full Moon) of our sky, cram-packed with variable stars (stars that have luminosities that vary over time), with some similar in mass to our own sun. Said stars do not emit enough ultraviolet radiation to ionize the hydrogen molecules located within.

Sources & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-111818-r-coronae-australis-complex/

Image Credit: European Space Observatory/La Silla Observatory