Monday, 28 September 2009

Observing 26-27 September 2009

The third clear night in a row! So I lugged the scope out to cool down and went back inside to watch Casualty on BBC1 (Yeah, yeah, I know it's sad, but I like Casualty - for those outside the UK, Casualty is a BBC-shown hospital-based drama series, not unlike ER) while waiting for the scope to cool and the first quarter Moon to set.
Once Casualty had finished I finished gathering my stuff together and decided to look at Jupiter, as I had not tried out the 12 inch on any Solar System objects before now. I know the blog title says Visual Deep Sky Observing, but once in a while I like looking at shallow sky stuff. Jupiter, despite being at quite a low altitude, gave me one of the best views I have had of it in the Northern Hemisphere. Bands and festoons were obvious and I could see the Red Spot. Even sticking the magnification up to 300x didn't degrade it too much, although at that magnification the seeing, while pretty good wasn't perfect, meant the image was a little unsteady.
Jupiter was also handy for aligning the Telrad and 8x50 finder.

Ok, onto the 'serious stuff'. I planned to knock off some Herschels tonight, so that was to be the main part of the session.

Chilly: 8 degrees Celsius (later 6 degrees C) with 82% humidity - the dew became a nuisance later on. No wind, 1st quarter Moon set late PM. Seeing II, transparency II-III. Visual limiting magnitude with the unaided eye was around 6.2 to start with, increasing to 6.4, this is based on how many stars I can see in the Great Square of Pegasus. However skyglow, due to moisture in the atmosphere, was quite pronounced; on drier nights you hardly notice it.

Instrument: 12 inch Dobsonian

NGC 7619 and 7626, galaxies in Pegasus. I had to wait until Pegasus and Pisces were clear of the house roof before looking for these, which are part of the Pegasus 1 galaxy cluster. I saw NGC 7619 and NGC 7626 with no problem, although dew formation on my secondary wiped out the other, fainter, galaxies in the area. Dew is a major problem here in the UK and I am going to have to make a dew shield for both the scope itself and the Telrad (the latter being very prone to dewing up).
Both galaxies are oval, with brighter middles. NGC 7619 is the brighter of the two. Nothing else seen, due to the aforementioned dewing. 61x, 101x

NGC 7742, galaxy in Pegasus. Oval, fairly dim although easy to find and see. Slightly brighter middle. 101x.

NGC 205, galaxy in Andromeda. When I saw this on the Herschel 400 list I looked for it on the chart. I couldn't find it on the chart, which was odd, but there was a reason for this; that reason is that it is better known as M110, one of the companions of M31. As Homer Simpson would say 'D'oh!'. Large, oval, fairly bright. Brightens somewhat, gradually towards centre. In a nice starry field. Fainter than M31 although it would be a showpiece in its own right if it wasn't overshadowed by its bigger, brighter and more famous friend. 61x

Looked for NGC 891. I have observed this galaxy before, with my 8 inch scope, but completely failed to find it this time. 891 is noted as being hard to find, but after 40 minutes of searching I gave up. I think I was in the right place, but the dew was making life awkward and wiping this already quite faint galaxy out.

NGC 752, open cluster in Andromeda. Large, loose cluster which fits neatly into 1 degree field of 40mm Plossl eyepiece, with room to spare. I started a sketch of this (although I hate sketching open clusters!) but didn't finish it due to the secondary dewing up. 61x

NGC 1664, open cluster in Auriga. Small, triangular o.c. with a chain coming south-east from it, like a tail. In fact it does remind me of a cat, with two brighter stars as eyes. Not rich. Around 30 stars of uniform brightness. 101x

Because of the dewing, a bad back and cold feet, I packed up earlier than intended at 0230 BST. Not a bad session, and I managed to tick off some Herschels, but the dew was a major pain. I am going to have to fashion a dew shield for the OTA and one for the Telrad.

I have sent off to First Light Optics for a new laser collimator, hopefully that should arrive tomorrow, but with the Moon on the rise again and some more unsettled weather this week, I won't be doing much observing for a while. As a footnote, I woke up this morning to a weird red glow over on the computer desk. Yep, my collimator had come alive; I must have left it switched on. This isn't going to save it from the bin, though, its unreliability means that its fate is sealed!

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