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.

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Image data

Name M103
Type Open cluster
Constellation Cassiopeia
Right ascension 01h 33m 12s
Declination +60° 42′ 00″
Distance 9.500 ly
Other designations NGC581