NGC6366 - Globular Cluster in Ophiuchus


NGC6366 - Globular Cluster in Ophiuchus

This from SEDS.ORG:

Discovered by A. Winnecke on April 12, 1860.

This globular cluster was included in the General Catalogue of John Herschel as GC 4301. It is a large and quite "open" globular cluster, as indicated by its concentration class XI.

NGC 6366 is quite faint and weakly concentrated even in intermediate-sized amateur telescopes. As its brightest stars are only of magnitude 13.6, larger telescopes are required to view them; the horizontal branch giants are of magnitude 15.7. The overall visual magnitude of 9.2, at its distance of 11,700 light years and taking into account the interstellar absorption in its direction, gives an absolute visual brightness of -5.77 magnitudes, or a luminosity of only about 20,000 times that of our sun. Compared to other globulars, the cluster is rather rich in elements heavier than Helium, which astronomers sometimes inacurately like to call metals. NGC 6366 is approaching us at 122 km/s.


Camera: StarlightXpress Trius SX814 w Astrodon Gen II RGB Filters
Telescope: Astro-Physics AP155EDF w 155TCC (reducer/flattener)
Mount: Paramount MX
Guiding: Borg 60mm achromat w SBIG ST-402ME guide camera
RGB 12 x 5 min each
Acquired using CCD-Commander, TheSkyX
Processed in PixInsight with some tweaks/cleanup in PS CC 2018

Click on the image above to see a larger version of the image.

Lucknow, Ontario
June 2018