H-beta filter

Hubble’s variable nebula, and H-beta filter targets

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.