by Albert Highe
Summer is thankfully approaching, bringing warmer temperatures and a higher probability of clear skies. The temperature never got below 43°F, but dewing became a small problem later in the night as the %RH reached the high 90's. For about an hour, some crud moved in. But after midnight, the sky was clear again. Seeing early on was excellent, but degraded a bit later. Transparency was fair. Six observers were present.
The temperature was slightly warmer, dropping only to 47°F. The %RH peaked at 80, so dew wasn't a problem. Seeing wasn't as good as on Friday, but transparency was better. Two observers left and seven new ones showed up. We had a very nice size crowd.
| Scope | 17.5" f/4.5 ultralight |
|---|---|
| Eyepieces | mostly 7mm Nagler T6, but occasionally the 5mm Tak LE when seeing permitted. |
With the Perseus Cluster, Abell 426, gone until this Fall, I've been contemplating new projects. This past week I researched the galaxy cluster Abell 1367 in Leo. I created a target list of approximately 200 galaxies within a 2°-diameter circle. As with A426, I downloaded DSS images for the region and labeled each of the target galaxies. Over the course of the two nights I logged 75 galaxies in this cluster. The total observing time was approximately 5-6 hours since I could only view early and late during the night, when A1367 is no higher than 55° of the horizon. Given my success this weekend with less than perfect skies, I would guess that 100-150 galaxies are within reach. During the next few days, I'll add my observing list, target highlights, and some of the finder charts to my website.
In between observations of A1367, I also explored other regions and observed some bright favorites. In particular, Abell 2197, Abell 2199, and Abell 2151, all within Hercules, look attractive for further study. I logged about a dozen galaxies in each. As with other rich galaxy clusters, even the detailed charts in the back of Uranometria aren't sufficient to identify all the galaxies that are visible. I plan to return with labeled DSS images for these areas as well.
A big THANKS to you, Michelle, for your hospitality.