Yes, using the manual system you have for altazimuth and altitude, you will need the base as close to level as you can make it. Any errors here will translate directly into pointing errors when targeting particular objects. Modern alt-az goto mounts automatically compensate for the base not being level.
Tuc 47 and the Tarantula Nebula are approx due south at the moment in the evening and Tuc47, in particular, would be at a low altitude, so my guess is that they were lost in the light pollution and glare from your place. Both are naked eye visible from my place, but I am well south of Hobart so have very dark skies when looking south.
Originally Posted by Sconesbie
A relatively clear night so I thought I'd head outside for an hour or so. I have two questions which I'll ask at the end.
Only a brief observation as the street lights seemed brighter than normal and my next door neighbour had outside lights on (plus my Mum who was staying with us kept turning our light on to see what I was up to).
So what did I see:
- Sombrero Galaxy (VERY FIRST TIME SEEING THIS). Faint but there none the less.
- M42 a bit faint due to street lights as it was a bit lower in the horizon.
- Jupiter (a given). Very clear. I spent a bit of time looking at this one.
What I couldn't find:
- 47 Tucanae
- Tarantula Nebula
I have a 10" dobosnian with a home made setting circle for azimuth. I used my phone compass and put azimuth on zero to north. I thought it was pretty well lined up. I located Sirius, checked it's co-ordinates using Sky Safari and ensured I was on the same setting. Back and forward centering my eyepiece and so on until it was right. I double checked with Jupiter and yep, pretty good. However, when I went looking for M42, I was out about 1-2 degrees.
Is it imperative that the scope is dead set level? Would that make a difference?
Second question: Is there a template that I can use for altitude (same as azimuth) for my dob?
Next time, I'll find a darker spot and seek out Sombrero again as I want to have another look.