Third light!

[Joe_L]

The clouds finally parted on Wednesday night so I got my new Nexstar 6Se out. My first light session was Jupiter and the moon a few weeks ago, and my second session last week I had a practice getting the alignment together - after following someone's guide to setting up backlash and approach and I then used 2-star with polaris and Sirius and seemed to get fairly good goto - used the tour and saw a few of the brighter galaxies and easier doubles - brilliant. Very pleased with my new toy!!

So I ordered myself a Barlow, a Revelation 2.5x, and Wednesday night was the first opportunity to try it. I managed to get Jupiter with my 18mm Excel SL plus the Barlow (equivalent to a 7.2mm) - looking noticeably larger than without the Barlow and predictably a bit harder to focus but I could still see some detail, though slightly washed out. I was happy with that and not surprised as I know as know its a tradoff between detail and size, and that combination would require good seeing conditions - always worth a try as they say!

So I turned to the stars. The sky seemed pretty clear to the naked eye but I was quite dissappointed through the telescope. I backed off to the standard Celestron 25mm and the stars just did not have that pin-point clarity that I saw in my first sessions - I remember being struck by the pinpoint effect. This time everything looked like minute fuzzy balls of wool (and yes, I did check focus!!). Using the barlow of course just gave me bigger balls of wool so I stayed with the 25mm. My question is, is this most likely to be a fogging problem or seeing conditions? I think collimation is ok as I got pinsharp stars the previous week. I tried warming the eyepeices with my hands and even used a torch to inspect the lenses and could see any condensation (ok, ruining my vision in the process but the object was familiarisation rather than DSO observing). Before sunset the sky was clearing but still a bit milky - my guess is this slight haziness was sufficient to cause the fuzz I was seeing, but I'm not experienced enough to be certain.

Joe

[Marki]

Depending how long you were out, maybe the corrector plate was dewing up? This happens pretty quickly with my 8SE, if I forget to put the dew shield on it.

Or maybe the seeing was poor and there could have been some high hazy thin cloud that wasn't easily visible. Sometimes the moon and planets seem ok through the thin haze, but the stars don't.

Changes in atmospheric conditions can make a huge difference to what and how well you can see even apprarently easy targets. One of the intriguing things bout astronomy for me