Messier 23

23 final

Object:   M23 (NGC 6494) Date:               2018 September 2
Type:  Open cluster
Constellation:           Sagittarius Time & altitude:          20.30 UT    17º
Catalogue data: Seeing (5 high):                               3/5
            R.A:                17h 57m Transparency (5 high):                   2/5
            Dec:                -19º 01 Telescope:     0.5m f4.1  Dob.
            Magnitude     5.5 Eyepiece       17mm Ethos              x120
            Size (mins)    27 Filters:            None


As on August 31, transparency overhead is good with NELM better than 5.5m and Milky Way on view but progressively milkier below about 30 degrees. The first of the autumn ground mist is evident this evening as well.

This is a very thin cluster with lots space separating the stars. The stars seem arranged in arcs and are mostly of similar brightness. There is a bright star on the NW edge.