Monkey Head Nebula

Cluster NGC 2175 is associated with a diffuse nebula, also numbered NGC 2175 and including nebula NGC 2174. Also, a small group of stars, north following [NE] of NGC 2175, is listed as NGC 2175S in the Sky Catalogue 2000.0.

Cluster NGC 2175 is listed in the Sky Catalogue 2000.0 as of 18' diameter, and total magnitude 6.8. It contains 60 stars, the brightest of which is of mag 7.55, and is also the the hottest, of spectral type O6; this is indicating a very young age. Its Trumpler type is given as IV 3 p n, and its distance at 6,350 light-years. A membership in the stellar association Gem OB1 is suspected.

The emission nebula NGC 2174-5 is listed with dimension 30x40'. It is excited to shine by the very hot brightest star of the cluster, HD 42088. The NGC decribes it as extremely faint, but on photos it is comparatively bright. It appears as of red color, irregular shape, and exhibits a combination of amorphous and filamentary structure. South following [SE] is an extension cataloged as IC 2159