More from Colorado

I got two more days in this week: on Wed I was back at my usual spot, where the transparency was improved by not quite at its best. No matter -- my 10" under these conditions is still nearly the equal of my 16" back in Ireland.

Thurs saw us camping at an old railroad cabin (no electricity, no water, middle of nowhere) rented out by the US Forest Service. It's at the bottom of Boreas Pass, so it's a bit lower than my normal site on Hoosier Pass (the lower altitude should help oxygenate my retinas), and it has essentially no passing traffic to mess with my dark adaptation. Plus, I can set up and then join the family at the campfire while waiting for the scope to cool and the sun to fully set.

Here's the Mewlon cooling, with the cabin in the background.

First night (Blue Lakes Drive, Hoosier Pass):

M8 Lagoon 7/22/2009 22:30 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Lots to see under dark skies. The main dark lane now wraps around the brightest section in a U shape, with the second-brightest section across it to the SE. There's a prominent double in the middle of the dark lane (which I centered my sketch around). A second, much more subtle dark lane separates that section and the open cluster from further nebulosity to the ESE.

Sketch to follow.

M4 7/22/2009 23:40 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Large but not very dense globular, almost more like a very dense open cluster. 100s of stars resolved at 100x. Strong linear asterism from SSW to NNE slightly to the E of center, with a weaker curved asterism more or less paralleling it to the WNW.

M80 7/23/2009 00:00 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Small dim globular. Grainy in averted at 100x, but no stars resolved. Grainy in direct at 180x, with 20 or 30 stars resolved in averted. Similar at 260x.

Sketch to follow.

NGC6760 7/23/2009 00:15 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Small circular smudge at 260x in a very rich field. No stars resolved at either 180x or 260x, nor does it appear to brighten to the center. Looks more like a planetary than a globular.

NGC6781 7/23/2009 00:25 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Similar in size and shape to globular NGC6760, although this one's a planetary. Much dimmer though, and magnification (260x) doesn't really help. Larger exit pupil is the key here, with the 32Mk80 and UHC the clear winner. UHC accentuates brightness difference N to S, the feathered edge to the N, and the slight minima to center.

Jupiter 7/23/2009 00:35 MT; Pickering 7, NELM 7, SQM 21.7
10" DK

Shadow transit of Callisto in progress, right below a very well-defined, but not red at all, GRS. SEB darker at south edge, and extending above the GRS. Dimmer STB visible across disk. NTB much closer to NEB, and dimmer than STB. Hints of dark barges in STB. 260x was sharp only very rarely, while 180x was sharp perhaps 30% of the time. Perhaps my best view ever of the GRS, and the shadow transit was quite a bonus.

Sketch to follow.

Again, the sketches will have to wait till get back to my scanner in Ireland.

Second night (Roberts Cabin, Boreas Pass):

M16 Eagle 7/23/2009 22:40 MT; Pickering 3, NELM 7, SQM 21.6
10" DK

Fills field of 17T4, making it difficult to detect unfiltered. Much easeir in 32Mk80, but still rather subtle. Looks more like a fat and stumpy Christmas tree to me.

UHC makes a world of difference, introducing some variegation to the nebulosity and hints of dark lanes on either side of the body, thus giving it much more of an eagle shape. (One of the dark lanes turns out to be the pillars of creation.)

Sketch to follow.

M7 7/23/2009 23:00 MT; Pickering 3, NELM 7, SQM 21.6
10" DK

Very bright central grouping surrounded (when slewing) by several much dimmer groupings. But even the bright central grouping barely fits in the field.

M20 Trifid 7/23/2009 23:15 MT; Pickering 3, NELM 7, SQM 21.6
10" DK

Very pretty with 3 of the 4 characteristic "clover leaf" dark lanes visible even unfiltered at 100x. UHC accentuates 3 and reveals a fourth. 180x more up-close and personal, but nebulosity notably dimmer, and UHC overpowers the view at this exit pupil (1.4mm). The seeing is abysmal, which may also be contributing the the degradation of the view at higher magnifications.

Sketch to follow.

Cheers,
-- Jeff.