Saturday, 9 February 2008

Observing session 8th February 2008

Conditions: Clear but misty at ground level, +3 degrees C. Seeing very steady.
Instrument: 4" refractor and 8x42 binoculars.
Place: near Sandown, Isle of Wight, England
Naked-eye limiting magnitude: around 6.0 to 6.2

For once the weather forecast was accurate. We're currently in a spell of pleasant, quiet weather with clear skies. After the rotten weather of the past few weeks this is a nice change.

I took the refractor out and set it up, but not without a fair bit of swearing as I dropped the tripod screws on the ground more than once.

I spent the time poking around Monoceros, a constellation I have shamefully ignored in the past. Monoceros is a constellation which deserves more attention, overshadowed as it is by its' more illustrious and object-packed neighbours, Orion and Canis Major.

The Rosette Nebula, NGC 2237-9: Monoceros' most famous feature is the Rosette Nebula. This is a ring of nebulosity around an open cluster NGC 2244. It is large and with a low surface brightness but is visible through binoculars under a dark sky. I used my 8x42 binoculars with an OIII filter stuck in the right eyepiece and could easily see the nebula as a round glow, slightly darker in the middle, around NGC 2244. Without the filter and with averted vision I could just about make out the nebulous glow. I had never previously attempted the Rosette, believing it to be beyond my binoculars' and local sky's capabilities. Obviously this is not so and this goes to show that it pays to have a go at these things.
I sketched NGC 2244 through the refractor at 45x.

There are loads of open clusters in the vicinity and I came across an interesting-looking one while scanning around the area with the binoculars. This was NGC 2301, a pretty group of stars stretched out in a north-south orientation, looking a little like one of those modern longbows used in present day sports archery. I used the refractor for a quick sketch.

The sky conditions were by now beginning to deteriorate somewhat due to increasing mist and the refractor was, despite the dew cap, becoming unusable because of vast amounts of condensation forming. No sooner had I cleaned the moisture off of the objective then the eyepiece fogged and when I wiped the wet from that then the objective fogged so I took down the refractor and resorted to using binoculars only. The mist was also attenuating the light from an upstairs window making life more difficult so I packed in, finishing up with a couple of planetary 'lollipops' - Saturn (with Titan) and Mars.

I will scan and post the sketches sometime in the next few days, plus some from the other evening,