Sunday, January 21, 2007

20070120 - Winter Messier objects with small optics

Session name: 20070120.2035

I showed up last night at TotL to observe with small optics. I began work compiling a list of results in observing the Messier objects in urban conditions with various optics. Others have done this and Tony Flanders' is the one I know best from his Sky & Telescope article and also his astronomy website. I intend to do a similar list with optics ranging from handheld bins to the 10" reflector limited to observations from TotL.

The night was pretty cold 16°F/-8°C, gusty at times with a clear, moonless sky. Naked eye,I could make out 12 stars of Lepus from tail tip to 3 stars of his ears. 4 stars of Columba were visible, the fifth one that is east of two central bright ones was difficult to resolve.

This session I had the Coulter CT-100, Takahashi bins, and the Fujinon 7x50 FMTR-SX Polaris. The plan was to swap the CT-100 & Tak bins on the Bogen 410 but the cold made use of the Bogen geared head difficult to use especially with gloves on so I just mounted the CT-100 and never unpacked the Tak. A Tele Vue 20mm Plossl was used exclusively with the CT-100 resulting in a 2.3° field of view and 22x magnification.

In handheld 7x50 bins, M35, M36, and M37 were apparent, in order of ease and resolution. All were soft, unresolved glows increasingly lower contrast with sky. M38 was not detected. M41 is easy with a few stars resolving and twinkling. In the F/4 4¼" reflector, all the clusters resolved with no issue. In the scope M37 is much more concentrated, desne with faint stars.

M45 and M42 were both seen without any problems, M43, not. Of all these, M45 was naked eye and "something in funny in the state of denmark" applies to M42 as one looks at the sword.

M1 & M46 were expectedly undetected. M47 was easily seen, small, sparkling. Of all the clusters, I prefer M47 in the handheld and even the Coulter this open cluster is attractive.

Since it was pretty cold and the wind could pick up pretty strong, I ended this little project earlier than expected. Is isn't often that I'd pack up early on a clear night but with equipment not being cooperative and a bit off my game I figured another opportunity will come.