Omega Centauri - NGC5139
Omega Centauri (NGC 5139) is the most brilliant globular cluster in the sky.
With an apparent size of 36 arc-min, it can be seen in the austral constellation Centauri with naked eyes, at dark skies.
At a distance of 16000 ly, it is formed by about 10 million stars being one of the most massive among the approximately 200 globular cluster orbiting our galaxy.
The average distance among the stars siting at the cluster nucleus is about 0.3 ly, so the sky in such zone of our galaxy should be 100 times brighter than ours.
This cluster is very ancient object. Although its stars are divided in different populations, some of them have an age of 10000 / 12000 million years, almost as old as our galaxy.
In the following annotated image appear a handful of distant galaxies in the background sky.
Technical Data
| Acquisition site | San Antonio de Areco, Buenos Aires, Argentina |
| Acquisition date | 3-13-2016 |
| Instrument | Newton GSO F4 200 with GPU coma corrector. |
| Mount | Sky-Watcher NEQ6, managed by EQmod |
| Guide | Off-Axis, with Lodestar camera |
| Camera | Modified Canon 600D/T3i No IR Filter (Full Spectrum mod, using Astronomik MC Clear) Refrigerated (regulated temperature) |
| Camera sensor temperature | 0°C (on-sensor measured and regulated) |
| Filter | Astronomik Clip CLS CCD |
| Integration | 20 x 2 minutes subframes - ISO 800 Total integration time: 40 minutes |
| Calibration | 49 flats, 400 bias, 84 darks. |
| Resolution | 1.1 arcsec/pixel 787 mm actual focal, 4.2 um x 4.2 um pixels |
| Native size | 5202 x 3465 pixels |
| Cropped size | 5038 x 3340pixels |
| FOV | 92' x 61' |
| Image center coordinates | RA: 13h 26min 50sec Dec: -47° 28' 55'' Rotation: 89.5° |
| Process | PixInsight 1.8 |