Messier 45

45 final

Object:   M45 (The Pleiades) Date:               2019 January 28
Type:  Open cluster
Constellation:           Taurus Time & altitude:          22.30 UT    43º
Catalogue data: Seeing (5 high):                               1/5
            R.A:                3h 47m Transparency (5 high):                   5/5
            Dec:                24º 07 Telescope:     0.5m f4.1  Dob.
            Magnitude     1.2 Eyepiece       8 & 17mm Ethos           x120 & x260
            Size (mins)    110 Filters:            None


My widest field is 50 arcmin with the 17mm Ethos. The cluster is the best part of 2 degrees across so my equipment is incapable of showing the cluster as a whole. I have therefore focussed on a detail and drawn the field around Merope, mag 4.2. The drawing encompasses most of the stars visible in the 8mm Ethos, a 23 arcmin field centred on that star. None of the other eight principal named stars of the cluster appear in this view.  The faintest star I have recorded (per Megastar) is only 13.8m. This is a measure of the poor seeing.

There was no trace of reflection nebula NGC 1435 which starts at Merope and envelopes the two brighter stars at the top of the drawing before turning W. I should have tried for it with Merope out of the field. The drawing shows a conspicuous blue-tinged circular glow around Merope. I don’t think this is proper nebula, merely scattered light from damp and dust on the optics.