Spitzer Sees Shining Stellar Sphere

Spitzer Sees Shining Stellar Sphere

Millions of clustered stars glisten like an iridescent opal in a new image from NASA's Spitzer Space Telescope.

Called Omega Centauri, this sparkling orb of stars is like a miniature galaxy. It is the biggest and brightest of the more than 150 similar objects, called globular clusters, that orbit around the outside of our Milky Way galaxy. Stargazers at southern latitudes can spot the stellar gem with the naked eye in the constellation Centaurus.

Omega Centauri – click for 800×913 image

More: Omega Centauri Looks Radiant in Infrared

Globular clusters are some of the oldest objects in our universe. Their stars are over 12 billion years old, and, in most cases, formed all at once when the universe was just a toddler. Omega Centauri is unusual in that its stars are of different ages and possess varying levels of metals, or elements heavier than boron. Astronomers say this points to a different origin for Omega Centauri than other globular clusters: they think it might be the core of a dwarf galaxy that was ripped apart and absorbed by our Milky Way long ago.

In fact, as would be appropriate for what was once an independent galaxy, it seems that Omega Centauri may contain its own intermediate-mass black hole:

Black Hole Discovered In Center Of Enigmatic Omega Centauri

A new discovery has resolved some of the mystery surrounding Omega Centauri, the largest and brightest globular cluster in the sky. Images obtained with the Advanced Camera for Surveys onboard the NASA/ESA Hubble Space Telescope and data obtained by the GMOS spectrograph on the Gemini South telescope in Chile show that Omega Centauri appears to harbour an elusive intermediate-mass black hole in its centre.