 
Image Data : Camera : KAI-4021 CCD Chip Telescope : 3" APO (SLOOH.COM) Teide Observatory Canary Islands Mount : Unknown Total Exposure : 5 min Sub Frames : 1 x 5 min Auto Guiding : No Filters : No Image Capture Software : None Processing Software : None Other Designations : C80 Image Data : Camera : KAF-09000 CCD Chip Telescope : 20" Dal Kirkham (SLOOH.COM) Teide Observatory Canary Islands Mount : Unknown Total Exposure : 5 min Sub Frames : 1 x 5 min Auto Guiding : No Filters : LRGB, Narrowband (HA 4.5nm, Oxygen III 500.7/4.5nm, Sulphur II 672.4/4.5nm) and UBVRI Photometric set (U=Ultraviolet 320-400nm, B=Blue 400-500nm, V=Visible 500-700nm, R=Red 550-800nm, I=Infrared 700-900nm) Image Capture Software : Processing Software : Other Designations : C80 Object Information : NGC 5139 is a Globular Cluster in Centaurus. Known as Omega Centauri. Discovered by Edmond Halley in 1677who 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[8]. 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.[9] 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.[10] 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 remains of the core of a smaller galaxy long since captured into the Milky Way. Information care of Wikipedia | ||||||||||||||||||||||||||