Astronomy Picture of the Day: 01/01/14 - The Magellanic Stream

No, that"s not a bleach stain on the Milky Way. This object is called the Magellanic Stream. It was discovered in 1965 in the southern hemisphere of the Milky Way, covering at least 180 degrees of sky (it"s about 600,000 light-years in length). The mysterious structure is located about 180,000 light-years from the Milky Way. The gas moves at excessive speeds, and in a direction that doesn"t match patterns found within the Milky Way. As a result, it has been the source of much astronomical scrutiny.

However, the long search for the object that spawned this beast is over. This structure was found to originate from the Large and Small Magellanic Clouds, two satellite galaxies of the Milky Way. Through this new data, originating from Hubble"s Cosmic Origins Spectrograph, scientists were able to determine that the material was likely freed from the gravitational bondage of the two satellite galaxies some 2-billion years ago, when the two galaxies interacted with each other. Most of the material is thought to originate from the Small Magellanic Cloud because it"s smaller and would have felt a stronger pull from the bullying Large Magellanic Cloud.

Another mystery solved. Yay.

Sources and further reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-010114-the-magellanic-stream/

Image Credit: D. Nidever et al., NRAO/AUI/NSF, A. Mellinger, LAB Survey, Parkes, Westerbork, and Arecibo Obs.

Astronomy Picture of the Day: 12/30/13 - A Cosmic Superbubble

This striking "cosmic superbubble" lies near the star cluster known as NGC 1929, which is located in the Large Magellanic Cloud -- one of the small satellite galaxies of the Milky Way.

Taken using the European Space Observatory"s "Very Large Telescope," here, you can see the many regions in the nebula, officially known as LHA 120-N 44, that are actively producing new stars. Said young stars are beaming intense rays of ultraviolet radiation into the surrounding expanse of space, causing the gas present to glow this brilliant shade of red.

As I briefly mentioned earlier, this region of space is inhabited by a super-bubble. Cosmic phenomena that shape this kind of structure do not actually form conventional bubbles. Instead, they are vast shells of material (such as gas and dust) that are shaped by the destructive forces of the UV radiation emanating from the central stars.

N 44 (the bubble"s formal classification) is actually very large. Its dimensions are estimated to be about 325 light-years by 250 LY. For instance, WASP-10b is a planetary system located about 300 light-years from Earth in the constellation of Pegasus. While our nearest galactic neighbors lie a little more than 4 light-years from Earth in the Alpha Centauri system. This bubble is so large, it could encase all three planetary systems!

Sources & Additional References: http://www.fromquarkstoquasars.com/apod-a-cosmic-superbubble/

Image Credit: Manu Mejias/ESO

Magellanic Clouds (Ready for editing)

For all of you southerners (people who live in the southern hemisphere), this is a sight that you might recognise when looking towards the night sky. Can you guess what these white blips are? There are actually three objects in this image that you can see, one on the left and two on the right. Truth be told, there are actually three on the right, but the third isn’t visible unless you’re looking at the original 73mb image (which you are not). So what do you think we are looking at here?

Find out at:
http://www.fromquarkstoquasars.com/magellanic-clouds-ready-for-editing/

Image:
Colin Robson

Astronomy Picture of the Day: 12/05/13 – E0102

In one of the most beautiful images ever taken of the Small Magellanic Cloud (SMC), Hubble reveals a greenish-blue shell of debris from a massive star that went supernova. The remnant, which is know as "E0102" for short (more formally known as 1E0102.2-7219) -- is located approximately 210,000 light-years away from Earth in the satellite galaxy of the Milky Way. (Locally, it"s about 50 light-years away from N 76, a star-forming region found in the outer trenches of the SMC).

The stark contrast in coloring in this composite image can be attributed to different elements located within the star forming region of the Small Magellanic Cloud. N 76 is primarily composed of glowing hydrogen emissions. Whereas, E0102 is an oxygen-rich environment that has a startling absence of hydrogen and helium (key components in star formation). It is believed that the abundance of oxygen in the surrounding environment can be attributed to a very large, old and unstable Wolf-Rayet star. Over the course of the last hundreds of thousands of years, the star lost most of its hydrogen envelope through stellar winds. Said material then carried off the outer-most shell of the star, leaving behind oxygen once the star exploded. Shortly after, the core contracted to become a neutron star.

As far as the age of the remnant is concerned, it is relatively young compared to many of its similar counterparts. The original supernova blast was estimated to have taken place about 2,000 years ago and is just now starting to expand into the interstellar medium. (This would essentially mean that the explosion occurred more than 230,000 years ago. It just took so long for the light from the event to arrive on Earth)

Sources & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-120513-e0102/

Image Credit: NASA, ESA and the Hubble Heritage Team STScI/AURA