IYA Live Telescope Today – Omega Centauri – NGC 5139

On April 9, 2009 the IYA Live Telescope was busy broadcasting from the Southern Galactic Telescope Hosting facility and fulfilling your “100 Hours of Astronomy” requests. Are you ready to take a look at the video that came from the adventure and to add it to our library? Then attention Astrofiend… Your request of Omega Centauri (NGC 5139) has gone live!

The following information is a cut and paste from Wikipedia:

Omega Centauri (NGC 5139) – Constellation: CENTAURUS

Omega Centauri – NGC 5139 is a globular cluster seen in the constellation of Centaurus, discovered by Edmond Halley in 1677 who listed it as a Nebula. Omega Centauri had been listed in Ptolemy’s catalog 2000 years ago as a star. Lacaille included it in his catalog as number I.5. The English astronomer John William Herschel recognized it first as a globular cluster in the 1830s. It orbits our galaxy, the Milky Way. One of the few that can be seen with the naked eye, it is both the brightest and the largest known globular cluster associated with the Milky Way. Omega Centauri is located about 18,300 light-years (5,600 pc) from Earth and contains several million Population II stars. The stars in its center are so crowded that they are believed to be only 0.1 light years away from each other. It is about 12 billion years old.

Though it is not a star, Omega Centauri was given a Bayer designation. Unlike other globular clusters, it contains several generations of stars. It has been speculated that Omega Centauri may be the core of a dwarf galaxy several hundred times its present size, which was ripped apart and absorbed by our Milky Way galaxy. Omega Centauri’s chemistry and motion in the galaxy is also consistent with this picture.

Reporting in the April 1, 2008 issue of The Astrophysical Journal, astronomers claimed to have found evidence of a intermediate-mass black hole at the center of Omega Centauri. The observations were made with NASA’s Hubble Space Telescope and Gemini Observatory on Cerro Pachon in Chile. Hubble’s Advanced Camera for Surveys showed how the stars are bunching up near the center of Omega Centauri, as seen in the gradual increase in starlight near the center. Measuring the speed of the stars swirling near the cluster’s center with the Gemini Observatory, the astronomers found that the stars closer to the core are moving faster than the stars farther away. The measurement implies that some unseen matter at the core is tugging on stars near it. By comparing these results with standard models, the astronomers determined that the most likely cause is the gravitational pull of a massive, dense object. They also used models to calculate the black hole’s mass.

Like Mayall II, Omega Centauri has a range of metallicities and stellar ages which hints that it did not all form at once (as globular clusters are thought to form) and may in fact be the remainder of the core of a smaller galaxy long since incorporated into the Milky Way.

We would very much like to thank Astrofiend for the suggestion of NGC 5139 and we hope you like the view! As always, you can visit the remote telescope by clicking on the IYA “LIVE Remote Cam” Logo to your right. We’ll be broadcasting whenever skies are clear and dark in Central Victoria! Enjoy…

(Information Source: Wikipedia)