Thursday 18th January 10.30 to 11.30pm No moon Observing from my back garden in Coalville
After several unsuccessful evenings, I finally found Hubble’s variable nebula. The trick is to wait until it’s at its highest point in the sky and therefore out of the worst light pollution, i.e. directly south.
I was concerned it would be so small it would be difficult to distinguish from a star in the low magnification wide angle eyepiece I was using to search for it – like Neptune and Uranus. However, when I actually found it I realised you’d never mistake it for a star – it’s too dim. The reason I’d had difficulty finding it was because it’s just very faint, even in my 16 inch Dob.
Hubble’s variable nebula looks a bit like a very small globular cluster – just a smudge at low magnification. At higher magnification of a 100 or 150x you can discern a triangular shape, with just a hint of a star at the tip. The best view was without a UHC or OIII filter.
Hubble’s variable nebula can be found by hopping from the star in the bottom of the drawing to a nearby double star, and then onto the Nebula. It’s just above and to the left of Orion.
Had another go with the H-beta filter. I could see there was something there when I looked at the California Nebula, but I think I was using too small a FOV to make out any shape. I could see a bit of a fuzz surrounding one of the stars in the belt of Orion, but no Horsehead nebula. M43 wasn’t any better with the filter. The only significant extra detail I could see was a line behind the bow in the Orion nebula. Not sure whether to keep the filter.
Stephen James O’Meara, in his book “The Caldwell Objects” describes it as looking like an “ignited match”, and I must admit that it does look like that in my window-sill image at https://roslistonastronomy.uk/monoceros-from-the-window-sill-29-11-2017