About this Image
The great variety of star colors in this open cluster NGC 4755, situated less than 1 degree to the
south-east of the brigth star beta crucis underlies its name: The Jewel Box.
One of the bright central stars is a red supergiant, in contrast to the many blue stars that surround it.
The cluster, also known as Kappa Crucis contains just over 100 stars, and is about 10 million years old.
The Jewel Box lies about 7500 light-years away, spannning 20 light-years across. North is right.
105mm TMB refractor with flattener at f/6.5
|Camera||SBIG STL-11000M at -20C, internal filter wheel|
|Date||Aug 13, 2004.|
|Sky Conditions||mag 6.5, high transparency, temperature 10 C,|
LRGB= 10:10:10:10 min (5-minute sub-exposures)
Image aquisition in Maxim DL 4.0; Image calibration, aligning, mean stacking, DDP and color synthesis in ImagesPlus;
Photoshop: color balance, cropped, unsharp mask;