Messier 7

Object:   M7  (NGC 6475) Date:               2018 July 16
Type:  Open cluster
Constellation:           Scorpius Time & altitude:         23.10 UT      3º
Catalogue data: Seeing (5 high):                               2/5
            R.A:                17h 54m Transparency (5 high):                   4/5
            Dec:                -34º 49 Telescope:     0.5m f4.1  Dob.
            Magnitude     3.3 Eyepiece       17mm Ethos              x120
            Size (mins)    80 Filters:            None


At minus 35° declination and just 3° altitude I can do little more than say I’ve seen the object. The lowest part of the primary mirror is looking at the garden shrubs. My widest field of view is with this eyepiece and is 49 arc minutes. This seems to be enough to take in the brighter members of the cluster. Presumably the outer reaches of the cluster are populated by fainter stars which are lost in something like 5 or 6 magnitudes of atmospheric extinction, dust etc.