NGC 5139 (Omega Centauri)
NGC 5139 (also known as Omega Centauri; Caldwell 80) is a globular cluster in the constellation Centauri. It has an apparent visual magnitude of 3.6 and its angular diameter is 36 arc-minutes. Omega Centauri lies at an estimated distance of 15,800 light years and it contains several million Population II stars. The stars in its center are so crowded that the average distance between them only 0.1 light years. The estimated age of the cluster is about 12 billion years.
The Equinox 2000 coordinates are 13h 26.8m, -47° 29´ which makes NGC 5139 a Southern Hemisphere object that is best seen during the spring. The Caldwell Spring Star Chart shows the position of all Caldwell objects visible during that season. Visit the Caldwell Catalog Photo Gallery to see more objects from this catalog. It is one of the more famous objects in the Caldwell Catalog.
Omega Centauri is the largest and brightest known globular cluster associated with our galaxy. It was discovered by Edmond Halley in 1677 who listed it as a nebula. Ptolemy included it as a star in his catalog 2000 years ago, but English astronomer John William Herschel was the first recognize it as a globular cluster in the 1830s. Omega Centauri appears nearly as large as the full Moon and is one of the few globular clusters visible to the naked eye. See Wikipedia for more details.
Technical Details
- Object: NGC 5139
- Other Names: Omega Centauri; Caldwell 80
- Object Type: globular cluster
- Object Data: Apparent Magnitude = 3.6, Angular Size = 36 arc-minutes
- Object Position (Equinox 2000): 13h 26.8m, -47° 29´, Constellation = Centaurus
- Date: 2021 Mar 20-23 (4 nights)
- Location: Chile Remote Observatory, Observatorio El Sauce, Chile
- Partnership: Operated in partnership with David Churchill
- Telescope: Planewave CDK-17 (with Focal Reducer: f/4.5; FL = 1945mm)
- Camera: QHY 16200A with Integral 7-position Filter Wheel
- Mount: Astro-Physics 1600GTO
- Guider: Agena Starguide II / SBIG STi
- Sub-Exposures: Astronomik Filters
- Luminance: 40 x 5 min = 200 min
- Red: 24 x 5 min = 120 min
- Green: 24 x 5 min = 120 min
- Blue: 24 x 5 min = 120 min - Total Exposure: 9h 20m
- File Name: NGC5139-CDK21-C01w.jpg
- Field of View: 38.9' x 58.3' at 0.64 arc-sec/pixel
- Original Image Size: 3630 x 4540 pixels (16.5 MP); 12.1" x 15.1" @ 300 dpi
- Data Acquisition: David Churchill
- Image Processing: Fred Espenak
- Maxim DL: Image Calibration, Stacking, Digital Development Processing
- Adobe Camera Raw: Noise Reduction
- Photoshop CC: Curves, Levels, Vibrance - Copyright: Fred Espenak