Plettstone 3/7-8/2008

Carter Scholz

After a nice drive along 140 past blossoming almond trees that looked snow covered, I arrived at Plettstone late Friday afternoon with my 12.5" Dob. Greg LaFlamme and Scott Baker were already there. Michelle and Paul showed up a bit later. As it grew dark the sky was not looking good. Sucker holes came and went, then Orion vanished before our eyes, and it was overcast by 10:30. Everyone waited a little, then turned in. I woke at about 3:30 AM, and the sky was brilliant. A few clouds were still on the horizon, but overhead UMa called. SQL meter read 21.53. I spent time with H-II regions in M101, logging 5471, 5462, 5461, 5447/50 (could not separate these two), 5455, 5453, and 5458. 12.5" Dob, 200x (sometimes bumping up to 320x).

On Saturday Greg and Scott and I cruised through Yosemite, great fun. Waterfalls were running well, and there was still some snow in the valley at 4,000 feet. Back at Plettstone Rick Ellis had arrived, then at dusk Mark Wagner and Richard Navarette. New moon, just over a day old, earthshine seemingly encircled by a thin brighter ring. A few cirrus, but the sky was good and got better. I'd looked up Comet 17P/Holmes's current position (still in Perseus, near Menkib and the California Nebula, not seen) and found it after a bit of scanning at 47x. Round, diffuse, slight brightening of background, still huge -- a degree or more. While in Perseus, I revisited Abell 426 and added 1274, 1281, and 1279 (=P12448).

My main targets were the Leo and Coma galaxy clusters Abell 1367 and 1656. The goal was to get my feet wet and start to familiarize myself with this rich territory; still, there were whole areas I didn't even look at. I could discern no detail in any of these galaxies, though they varied in size, shape, and brightness; many but by no means all required averted vision.

Abell 1367 was the easier group to locate and navigate; naked-eye 93 Leonis is at one corner of a distinctive five-star asterism that directly overlaps the center and south of the cluster. In Abell 1367 I spotted: 3861, 3820, 3822; in the center a neat chain: 3837, 3842, 3841, 3845, 3844, 3840, and off to one side pf it UGC6697; 3875, 3873, 3860, 3862, 3857, 3868, 3867.

Abell 1636 is between beta and 31 Coma Berenicis; an oblique 20'-long triangle of mag 7-8 stars has one vertex planted in the center of the cluster; another mag 8 star 30' south lies near another sub-group. In Abell 1636 I spotted: 4889 (already observed), 4874, 4886, 4898, 4864, 4869, 4865, 4860, 4881, 4895, 4907, IC4051, IC4041, 4921, 4923, 4919, 4911, 4842A/B, 4839, 4840, 4853. Humidity was high and transparency fluctuated quite a bit during the night, and that made quite a difference from one moment or hour to the next as to whether the same area was a dim amorphous blur or a group of distinct smudges. From after midnight till about 2 AM the sky was especially transparent. I referred to some invaluable finder charts and observing notes by Albert Highe (http://pw2.netcom.com/~ahighe/), and Steve Gottlieb (http://www.astronomy-mall.com/Adventures.In.Deep.Space/agcintro.htm).

Thanks again to Michelle and Paul for making this fabulous site available to us.