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