Globular Cluster NGC 4833 in Musca
|Apparent size:||14 arc-min.|
|Diameter:||88 light years.|
|Distance:||22,000 light years.|
|Exposure:||22 x 170 sec = 62 minutes.|
|Field of View:||80.6 x 56.4 arc-min; up is 261 degrees E of N.|
A southern globular cluster located in the constellation of Musca, just 30° from the South Celestial Pole. The distance to C105 is about 22,000 light years. Looking through the Milky Way disc plane, it is partially obscured by galactic dust.
The second brightest bright star, near Delta, is blue-white giant LS Muscae, a fifth magnitude B-type variable star about 1,000 light years away. It is part of a multiple star system.
You can see an annotated version of this image provided to me by Astrometry.net – a free automated astrometric calibration service which creates accurate astrometric meta-data for any useful astronomical image.
EDIT: There’s a bright star near the globular cluster (in the 11 o’clock direction) which was not identified by Astrometry.net. I looked on Google Sky and found it was just a pinpoint like all the stars around it.
A variable star!
My gif making skills are a bit ham-fisted but here you go……
The things you learn by chance…..
|SkyWatcher Esprit 120 mm apochromatic 3-element refractor.|
|840 mm focal length @ f/7 with field flattener.|
|Baader L-Booster UHC-S light pollution filter 2458276.|
|SkyWatcher EQ6-R Pro mount.|
|Camera: ZWO ASI 071 MC Pro (CMOS 28.4mm 16 Mpx)|
|ZWO ASI120 guide camera, using PHD2 software.|