NGC 4755, Jewel Box Cluster

NGC 4755 is an open cluster in the constellation Crux, the Southern Cross. It is known as both the Jewel Box and the Kappa Crucis cluster. The cluster was originally discovered by Nicolas Louis de Lacaille in 1751–1752. This cluster was later named the Jewel Box by John Herschel when he described its telescopic appearance as "a casket of variously colored precious stones". (Telescope Live)

The cluster is composed of bright blue supergiant stars. Some of which are variable stars. The bright red star is Du Cru a red supergiant and slow irregular variable star. (Astronomy and Astrophysics, aanda.org)

This object is only visible in the southern hemisphere.

Image processed by Andrew Macica, original data from Telescope Live.

Imaging Details:

Observatory: Rio Hurtado Valley, Chile

Telescope: Planewave CDK24

Aperture: 610 mm (24 inches), f/6.5

Focal Length: 3962 mm

Camera: FLI PL 9000 CCD

Filters: LRGB

Total Exposure: 10 hours 50 min.

Image Processing: PixInsight 1.8.9-3 Ripley (x64);

BlurXTerminator, NoiseXTerminator, StarXTerminator (RC Astro);

Adobe Photoshop 12.5.1;

Adobe Lightroom Classic 14.1.1

Instruction on PixInsight from Adam Block Studios.