Remember the galaxy in a jeweled cat collar in Men In Black? The Hubble Heritage Team (credit to A. Zezas & J. Huchra from the Harvard-Smithsonian Center for Astrophysics) have shot the “sharpest image ever taken of the large “grand design” spiral galaxy M81″. They remind me of each other.
The picture of which they are justifiably proud was made from data assembled from 2004 through 2006. Astro-photography obviously does not base itself on 1/60th of a second. The composite image was made from blue, visible and infrared-sensitive images.
M81 is similar to our own Milky Way which gives us a chance to see the architecture of a spiral galaxy like our own. It may be 11.6 million light-years distant but it is tilted obliquely to Earth which allows for a good view. It is a bright galaxy from earth — one of the brightest with a magnitude of 6.8. The magnitude implies that it might be able to be seen by the naked eye. It is on the edge.
There are spiral arms made of younger stars of bluish hue. These are hot orbs that are only some few million years old. Hubble has become so sharp that it is able to see individual stars even at almost 12 million light-years (time traveling, we see what was a scant 12 million years ago). It can make out dust clouds of fluorescent gas and star clusters as well.
The “central bulge” of M81 is made of older stars, redder stars and is “significantly larger than the Milky Way’s bulge”. When I publish this there could be a rash of spam aimed at increasing the size of your “central bulge”. But we will know that we can’t compete with M81.
It even has a bigger black hole at its center than our home galaxy. Fifteen times larger in mass. Hubble scientists had shown in the past that the size of the black hole is directly proportional to the size of the central bulge.
Scientists have also decided to study further the theory that the spiral arms are giving birth to a flood of new stars because M81 had a “close encounter” with another spiral galaxy (NGC3077) and a starburst galaxy (M82) about 300 million years ago
Hubble, the Space Telescope, is a cooperative venture of NASA and ESA (the European Space Agency).
Visit their sites and NASA for a lot more information on the contributions of the orbiting telescope and the way in which the information was collected.
Remember, kids, unprotected close encounters can cause the birth of baby stars. Watch your central bulges and keep your black hole under control.