Stu

I thought I would start this off as a way of logging what is possible with a small refractor under poor, urban skies. By poor, what do I mean? Well I live a few miles south of Heathrow, which basically wipes out most things to the north. I am on the edge of Walton on Thames, and have a relatively decent southern view over fields, but there are houses in the way so the seeing is often mixed. My NELM is normally around 4.2 to 4.5 but can be better or much worse depending on the transparency. Background sky brightness is around 18 to 18.5 in the best direction, so many galaxies are a challenge. For reasons of convenience, and because I love them, I have a collection of smallish, but decent quality refractors which are my most commonly used scopes. TV76 TV Genesis Astrotech 106mm EDT The first two are small and light enough to use on a mini giro on an Induro AT413 tripod, very quick to set up and pack down. The triplet is heavier and I normally use that on an EQ6 tripod, previously with a giro but will use on the mini until it sells! So, just a quick comment on last night. I had been playing with the collimation on the Genesis so thought I would give it a try out. I had a quick half hour under some nice skies before going out. I was just testing really, but had nice views of Jupiter with GRS, M45 and M42. This scope is lovely for flat, widefield views; at 500mm focal length, a 21mm ethos gives a 4.2 degree field of view, a 17mm gives 3.4. Under a dark sky (which I have yet to get it under!) objects like the Veil and NA nebula should be lovely, particularly with Lumicon UHC filter. I will try to post up about what is achievable/visible in these scopes under my skies as a reference for people. One example of the challenges.... Many of you will have seen the SN in M82 which is a relatively easy target under reasonable skies or with a little more aperture. With my 106, I just about managed it using averted vision. It was probably one of the hardest things I have managed to observe. On another occasion with my 12", it was trivially easy to see! Just finding M82 under light polluted skies can be a challenge in itself! I tried to see comet Panstarrs (whichever one it was ....), and eventually concluded that it was invisible from my skies. I tried scope and binoculars, but it was hopeless. I visited a relative in Bakewell and found it within seconds in the binoculars. Background sky brightness and surface brightness of objects are key to understanding what is visible and what is not. I will confess to a little frustration, seeing posts on here discussing light polluted skies, followed by reports I can only dream of from home. I think there is a big difference between local light pollution in the form of nearby streetlights and houses, vs the horrible orange grey glow which hangs over the larger cities. If your sky is fundamentally ok, then it is possible to block out local annoyances. The other way round there is nothing you can do. So, my aim is to focus on what can be achieved with limited aperture kit under poor skies, how to identify good targets (ie visible!) and a description of what I have seen. The answer generally at the moment is 'very little cos it's cloudy', but I shall be back when it clears. Cheers, Stu