Observing Report – 2023-02-13 – WSP Night 1/Visual Targets

Anticipating days ahead that I would be tired on the first WSP night after two days of traveling, and setting up camp and equipment on the day of arrival, my objective for the night was to focus (sic) on visual observing, and to get as far down my target list as I could before giving it up for the night.

The equipment for this session was G11 on the lightweight tripod, Tele Vue NP101is with a Panoptic 35 eyepiece. Set up was a little more involved than usual because I had disassembled the telescope, rings/dovetails, and other components for packing. Even so, set up during the day and start up as nightfall approached went flawlessly.

I did a scope polar alignment, and two-star alignment using the mount hand controller. I slewed to targets using the hand controller, and except for a few that were very close to the horizon all slews placed the target well within the field of view. The computer was not used in managing any part of this session.

I am not sure, but I attribute the “off” slews near the horizon to atmospheric refraction close to the horzon. I could have tested to see if the pointing error was in the N-S direction, but I didn’t think to do it in the heat of the moment. There may be a way (King tracking mode?) in the mount software that compensates for atmospheric refraction.

The temperature was in the mid-70s at the beginning of the session, and dropped into the mid-60s by the time I shut down. There were light breezes throughout the night. I began the session in shorts and a t-shirt. As the night wore on, I added first a long sleeve shirt and long pants, then a sweat shirt, and finally I swapped the sweat shirt for a coat. I was comfortable all night.  

The sky was clear throughout the session, but I noticed clouds staring to build after I had shut down and was walking away from the scope at about 0245. Even if fatigue has not ended the session, it would have ended a short time later than it actually had as a result of the clouds.

The sky was reportedly about Bortle 2.5. The winter Milky Way, near the meridian at the beginning of the session, wheeled westward toward setting. I could visualize how the winter Milky Way continued in a straight line that extended below the horizon, and would be rising just before dawn as the summer Milky Way was setting just before dawn. This was the first time that I had observed this phenomenon.

As for individual targets, I hit the some of the usual ones for a warm up. This included M42, M45, and several globular and open clusters in the Messier and NGC catalogs.

Most impressive were Eta Carina Nebula and Omega Centauri Globular Cluster. Both of these targets were viewed very shortly after rising. Eta Carina does not ascend much higher than it was when I saw it, but I will want to observe it again visually as it culminates. I see no point in trying to image it. The scope/eyepiece field of view was 4 degrees, and even so, the amount of field that it covered was astonishing. Even though it was low on the horizon,  was able to discern some detail in the nebula.

Omega Centauri was a similar experience. Low on the horizon when I observed, but its size was impressive. I switched to a Nagler Type 4 eyepiece and still was not able to resolve individual stars. In addition to my astonishment at its size, I found that it appeared somewhat menacing in the eyepiece. This object will ascend to a half-way decent 15 degrees at culimination, and I intend to image this target.

I did not note the time, but some time around 0100 I observed what was by far the brightest and longest lasting meteor that I had ever observed. It was about 45 degrees elevated from the horizon moving in a south to north direction passing off to the east of my location. It left a wide trail, and I could see an even wider green coma at the head.

I did not monitor the relative humidity and dew situation during the session. Optics and metal parts stayed dry all night. There was dew on the plastic equipment cases.

I had no issues that will required attention on the next day. I will engage in some effort to reposition the scope and to reconfigure for imaging.

Overall, this was an enjoyable session. It seemed that after a rather long interval of not using visual observing skills, they seem to be intact.

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