Astronomy Picture of the Day: 11/26/13 - Hercules A; Making the Unseen Seen

This is the elliptical galaxy known as Hercules A (formally designated as 3C 348). Other than being visually stunning, this galaxy is notable because it emits nearly a billion times more radio waves than our sun does, making it one of the brightest radio-emitting objects in the constellation of Hercules.

The super-massive black hole that lies at the heart of Hercules A, which is more than 2 billion light-years away, is responsible for manufacturing the spectacular jets seen here. Suffice to say, the black hole is powerful and quite massive, as is the galaxy in general. Compared to the Milky Way, it"s 1,000 times more massive -- with its central black-hole containing the mass of 2.5 billion suns (this makes it approximately 1,000 times massive than the black-hole in the center of our galaxy, Sagittarius A*)

This image is a composite, showing Hercules A in optical light from the Hubble Space telescope"s Wide Field Camera 3, and the recently upgraded Karl G. Jansky Very Large Array (VLA) radio telescope. The VLA revealed the enormous jets that are typically invisible when viewed at optical wavelengths. They are composed of high-energy plasma beam, capable of shooting superheated material off into interstellar space at speeds close to the speed of light. The jets extend almost 1.5 million light-years in width and are only visible using special filters, but this image portrays how they would look if we could see them.

References & Further Reading: http://www.fromquarkstoquasars.com/astronomy-picture-of-the-day-112613-hercules-a-making-the-unseen-seen/

Image Credit: NASA, ESA, S. Baum and C. O"Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STScI/AURA)

Galaxy Classifications: From Dwarfs to Spirals and Beyond

Surprisingly, over the course of most of humanity"s existence, we had no idea that other galaxies even existed. All we could see was our own little corner of the universe. It wasn"t until the early 1900"s that the nature of the so-called "Andromeda nebula" was discerned. Edwin Hubble settled the galaxy vs. nebula debate in 1925, and it was finally revealed that this "nebula" was actually a galaxy containing some 400 billion stars and not simply an extension of our own galaxy. Almost 100 years later, our reality (and relative insignificance) is well known, as we are now aware of the fact that the universe contains several BILLION large galaxies, many of which are similar to our own (current estimates guess that there are 100 to 200 billion galaxies in the Universe). With that revelation, we"ve learned that galaxies come in all shapes and sizes too. "So what other kinds of galaxies are there," you might ask? Here are the main types:

To learn about all the galaxy types, see:
http://www.fromquarkstoquasars.com/galaxy-classifications-from-dwarfs-to-spirals-and-beyond/

Image source:
http://qproject.net/Universe/281236_534286593250951_619997205_n.jpg