It's been a while since I penned a report. Several factors have conspired to reduce my time out under the stars, and I was very glad of the time on Wednesday. I had to work the next day so I planned to leave early, but the conditions were nice enough that I stayed late. It buoyed me up enough that I wasn't even a zombie at work the next day...
| Observer | Robert Leyland |
|---|---|
| Date | 20 June 2001 |
| Time | 2200-0100 PDT (UT -7, or 0430-0830 21 June 2001 UT) |
| Location | Lake Sonoma CA, 38°43'N 123°02'W Elev ~1100 (Lone Rock Flat) |
| Weather | 15-20°C Temp ~30% Humidity |
| Seeing | LM ~6, transparency 9/10, steadiness 7/10 breezy |
| Equipment | 8" F6 Dob, Telrad + 7x50 finder scope, Pentax XL EPs |
Arrived at about 8:45 to find Steve Gottlieb already setting up, and Dave Staples just turning off his engine. We chatted, and helped Steve set up his 17.5", when Steve LaForge arrived with his wife Jeanie.
Conditions were pleasant with an on/off breeze that sometimes blew papers away, but wasn't too bothersome. As it got dark, we could see that the horizons were clear, but the air was still warm, and views of Mars were mushy. The stars through Scorpius were twinkling.
In this late spring, early summer time, I had not expected to be able to finish my survey through LEO as it has been getting lower for the last few sessions, but the air was pretty steady in that direction, and it was the tail area that I wanted to work on anyway. So I took a peek at some of the brighter members to get an idea of the seeing. NGC 2903 was out of the picture, but M65/66 were good, and NGC 3628 was easily seen, as was NGC 3593 on the other side of the wall of stars by the M65/66 pair.
Picking up from my list, I tried for NGC 2501 & 2507, which are a pretty faint pair of galaxies above 65/66. No luck, I had the starfield but no dice on the galaxies. Not such an auspicious start. [perhaps it was too early in the evening, or they were too low]
Perservering I tracked down the NGC 3608 group. This was more like it, a pair of tiger eyes in the night. Ok, so this is in the Lion, yet the lines of the Shelley poem popped into my head... "Tiger Tiger burning bright, in the forests of the night" as the bright circular pair of 3507 and 3508 stared back at me. Pushing up the magnification to 120x helped bring out NGC 3605 which needed averted vision to see at 55x. My sketch (crude and quick) shows a little more fuzziness around 3607, but I was probably seeing the three field stars next to it as one group. A little further away is NGC 3599 and it needed averted vision to spot at 55x also.
Close by are more more galaxies, an easy hop away to NGC 3626 which has a nice oval shape, with some roughness at the edges that is more obvious at 120x.
NGC 3659 a sizeable oval patch with no core; a field star off to the side helps identify it. It is similar in shape and size to 3608, but much fainter.
Leo is full of galaxies, and groups of galaxies too, next up was NGC 3691 and its little friends. The two brightest members were easy to see and the adjacent "stars" seemed cloudy, which is a good hint that they are actually galaxies. Leo was getting a lot lower by now, and identification was much more difficult. I think I spotted 3691 and 3655, with fainter 3684, 3686 and 3681 at the limits of perception.
Steve Gottlieb showed us all a nice line of galaxies in Draco (NGC 5981,82 and 85) which should really be considered for any textbook, as neatly lined up are an oval, a circular and an edge on galaxy, like specimens on display. These were awesome in his 17.5", and nice in my 8" too. With the brighter oval and circular members being easy direct vision, the edge on needed averted vision at 55x, but by increasing the magnification to 85x, and thus darkening the background, the edge on galaxy [5981] was easier to see.
As late as it was I had one more challenge to attempt. There was a post on one of the (too numerous) mailing lists about "Project Pluto" as an observing challenge. I had seen Pluto the year before in Dick Flasck's 17.5" telescope, but armed with good finder charts could I find it in my 8"?
Pluto is kind of special in many ways, it is the furthest currently recognised planet. Although that is subject to change, both orbital and political, as Pluto may lose it's planetary status sometime in the near future. Also having read "The Search For Plant X" as a kid, and then getting to meet Clyde Tombaugh at a small gathering at Sonoma State in the late '80s I knew just how big a challenge finding it originally had been. Computers, and extended observations have made it a tad easier for us amateurs to find it again.
Of course I got distracted, stopping at M107 in Ophiucus on the way. However the finder charts were excellent, and the area containing Pluto was easy to find, hopping from 13 Oph to 20 Oph out to the target area.
Determining which faint point of light was the planet itself was more of a problem. Above 20 Oph, there is a 6.6 mag star forming a rough line of four stars with a 9th magnitude and a pair of 8th magnitude stars. Right off the end of the 8th mag pair was a faint point that wasn't quite charted. It was in line with the predicted path, and looked to be in about the right place, interpolating between the marked points. To confuse things, there is a 16th mag star there, but since I couldn't see other 16th mag stars I was pretty sure this was Pluto.
I called Steve and David over for a peek. Steve confirmed that it was Pluto using my charts, and pointed out that the 16th Mag star was directly in-line with the 8th mag pair, while my Pluto candidate was a little to the left.
Stave also pointed his 17.5" on Pluto for extra corroboration. It is just a point of light, but a very interesting one!
References:
NSOG - Night Sky Observers Guide -- Kepple and Sanner
Pluto Charts - http://members.aol.com/_ht_a/billferris/pluto.html