M103 (also known as NGC 581) is a relatively small open star cluster in the constellation Cassiopeia.
The bright star at the right of the image is Delta Cassiopeia.

It lies at a distance of about (estimated) 9.500 light years and is one of the most distant open clusters.
The age of this cluster is about 25 million years.

Other versions

Previous/older images:

Image data

Object info
Name M103
Type Open cluster
Constellation Cassiopeia
Right ascension 01h 33m 12s
Declination +60° 42′ 00″
Distance 9.500 ly
Other designations NGC581
Image info
Image date Sep. 30, 2011
Light frames 20x 3 min. UHC-S unbinned
Total integration 1h
Dark frames 10x
Flat frames 10x p. filter unbinned, created with an A3 size Posterpoweruk flatfield panel
Bias frames 10x
Software used CCDOps, CCDSoft, ImagesPlus, Photoshop CS4
Processing CCDOPS was used for focussing. Image Acquisition was done using CCDSoft.
All separate frames were calibrated, aligned and stacked in MaxIm DL5 Pro.
Photoshop CS4 was used for further processing – curves adjustment, levels adjustment, etc.
Noel Carboni’s toolset was used as well (Local Contrast Enhancement, Deep Space Noise Reduction).
Equipment info
Telescope TMB/LOMO 80/480
Corrector Televue 2″ TRF 2008 flattener/reducer (FL: 384mm f/4.8)
Mount Losmandy G-11
Camera SBIG ST-8300M
Guide camera Atik 1HS Mono
Guide scope Vixen VMC110L
Autoguide software Guidemaster
Filters Baader 2″ UHC-S
Location Landgraaf, The Netherlands
Image comments

Quite humid conditions.