Braving the weather for an IC, Arp, Abell and Mars

Transparency was awful, no doubt in part because of the reflective snow covering the ground. But on CloudyNights David Knisely had recently suggested using an H-beta filter on IC405 (a nemisis of mine if there ever was one), so I gave it a go.

IC405 Flaming Star Nebula 1/8/2010 21:20 UT; Pickering 9, NELM 5.5, SQM 20.3
125mm Refractor @ 40X, H-beta

Extremely difficult in 16" Mak, with only the edges of the dark region to the NW of AE Auriga visible. H-beta filter of some help, but not much.

Field size of FC-125 helps considerably, and the H-beta seems more effective here too (perhaps due to 25% larger exit pupil). Filter shows fan extending to NE of AE Auriga, with edges from AE Auriga to NNW and from AE Auriga to ESE. Difficult to tell if any of it is visible unfiltered.

Chuffed by that success, I went on to a couple more difficult targets:

Arp145 MCG-07-06-010 1/8/2010 22:01 UT; Pickering 9, NELM 5.5, SQM 20.3
400mm Mak-Cass @ 325X

Direct-vision poorly-condensed semi-stellar core to E of double star, surrounded by an extremely fleeting and stubby averted-vision arc. Ring not seen.

Abell 4 PK 144-15.1 1/8/2010 22:31 UT; Pickering 9, NELM 5.5, SQM 20.3
400mm Mak-Cass @ 150X, OIII

An epic battle between exit pupil, image scale and filtration:

Hints of an averted-vision smudge unfiltered at 150X and 335X, but not holdable and difficult to acquire. UHC eases acquisition slightly at 150X, holdable perhaps 30% at 235X (nearly 100% under motion), but no help at 335X. OIII doesn't do much for acquisition, but holdable at 150X, and no help at 235X.

These edge-of-visibility targets were taking quite a bit of time, so I was well-and-truly chilled at this point. However, you might have noticed the Pickering 9 reading, and well, one doesn't skip Mars when in season on a Pickering 9 night. I didn't take any notes here because I'm not much of a planetary guy and I don't really know what I was looking at, but I thought the sketch turned out nice.



Cheers,
-- Jeff.

Very nice Jey!

I really like the Mars one Jeff
Excellent!

A great collection Jeff, Mars is fantastic, thanks for the show.

Paul

Thanks, everyone!

-- Jeff.