The name is plain: Hoag's Object. But what a sight! Hot, blue stars in a sparkling ring around the core of a galaxy 60 million light years away in the constellation Serpens.
The bright ring is filled with young stars, which are hotter and bluer than the older stars in the yellow core. The "gap" around the core may actually contain faint stars and star clusters. Even a small background galaxy appears just inside the ring at the upper right.
The galaxy is about 120,000 light-years across, slightly larger than our own Milky Way.
This galactic oddity exhibits no sign of a collision with a second galaxy. Some scientists theorize that the blue star circle is the remnant of a galaxy that passed close by the central one, some 2 billion or 3 billion years ago.
Hubble watches two Spiral Galaxies collide
|M51: A CELESTIAL BEAUTY!
A Hubble photo of whirlpool galaxy M51 offers new insights into the formation of stars, and a new twist on the composition of galactic arms.
M51 is 20 million light-years away, in the constellation Canes Venatici. Why is M51 so pretty? The bright red spots dotting the spiral arms and dust clouds of galaxy are regions of STAR BIRTHS. These are triggered by the gravity of a neighbor galaxy (just off the edge of the image).
The clusters of young, luminous and energetic stars are glowing red because this is the color of hydrogen gas emissions.
Images from Hubble and Kitt Peak Observatory in Arizona were combined in this composite picture. They reveal the intricate structure of cold dust clouds associated with the hot hydrogen emissions. Note the darker dust "spurs" branching out almost perpendicular to the main spiral arms.
M51 Whirlpool Galaxy CLOSE UP PHOTO