NGC 5139 - Omega Centaury cluster

NGC 5139 is a globular cluster of the Milky Way with an estimated mass of approximately 10⁷ solar masses. Its distance is about 15,800 light-years. The structure is defined by a high stellar density in the core and a regular radial distribution. The stellar population is multi-generational, with chromatic variability due to differences in temperature and age.

Acquisition setup

- Telescope: Takahashi FSQ-106ED f/3.6

- Mount: Paramount MX+

- Camera: QHY600M CMOS, binning 1x1, sensor temperature –10 °C

- Filters: Astrodon LRGB (telescope.live dataset)

- Location: Remote observatory Heaven’s Mirror, Yass, NSW 2582, Australia

Dataset and integration

All light frames are 300 s, binning 1x1, –10 °C.

- L: 25 frames

- R: 22 frames

- G: 19 frames

- B: 23 frames

Total integration time: 7 h 25 min.

Processing workflow

- Star alignment and integration for each channel.

- Channel Combination to generate the RGB image.

- Gradient correction.

- Image Solver and Spectrophotometric Color Calibration.

- Application of BlurXTerminator, NoiseXTerminator, and StarXTerminator.

- StarStretch (Seti Astro script) for stellar saturation adjustment.

- Statistical Stretch (Seti Astro script).

- Creation of a luminance mask on the starless image to enhance faint diffuse structures around the cluster.

- Adjustment of chromatic saturation and micro-contrast.

- Reintegration of stars using Screen Star.

- Final resampling.

Dataset selection rationale

The dataset was selected for training and practice purposes, due to temporary inability to operate the personal setup caused by a left-shoulder injury. It also provides access to southern-sky targets not observable from the user’s latitude.