NGC 663 & NGC 654

Common Name: Lawnmower Cluster

Also Known as: Caldwell 10 (NGC 663)

Object Type: Open Cluster

Constellation: Cassiopeia

Distance from Earth: 6,850 light years (NGC 663), 7,830 Light Years (NGC 654)

Apparent Magnitude: 7.1 (NGC 663), 6.5 (NGC 654)

Coordinates: RA 01H 46M 0S DEC 61 deg 15 min 0 sec

Actual Size: 50,000 light years (NGC 663)

Apparent Dimensions: 16 arc-minutes (NGC 663), 5 arc-minutes (NGC 654)

Discovered by: NGC 663 and NGC 654 were discovered by William Herschel in 1787

Description: NGC 663 is a relatively large, young open cluster. It has an estimated 400 stars and spans about a quarter of a degree across the sky.
The star cluster is assumed to form part of the stellar association Cassiopeia OB8, that is located in the Perseus arm of the Milky Way, along with the open clusters M103, NGC 654, NGC 659, and some supergiant stars scattered between them, all of them having similar ages and distances.

NGC 654 is 2,400 parsec away. It is a very young cluster, aged approximately 15 million years, but it could be as old as 40 million years, with a time spread of star formation of at least ~20 Myr.
The central region of the cluster shows less reddening than the rest of the cluster. One explanation is that between the Solar System and the cluster lie two dust layers, one at 200pc and one more at 1Kpc. Behind the cluster is one more dust layer.
The cluster has approx. 80 members, including three Be stars and a few luminous stars like HD 10494 and F5Ia.
The earliest spectral type is around B0.
NGC 654 is also assumed to form part of the stellar association Cassiopeia OB8. NGC 654 contains about 60 stars.

Click Below Image(s) for Full Size:

The NGC 663 group can reportedly be detected with the unaided eye, although a telescope is recommended for best viewing. The brightest members of the cluster can be viewed with binoculars.
The NGC 663 group is circumpolar and therefore visible all year round.
It appears highest in the sky during October, November and December

Platesolve

NGC 663 & NGC 654 Open Clusters

Imaging Details
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