Plettstone - 3/20/04

by Bob Czerwinski


Ah, galaxy season! With ol' Sol once again having crossed the celestial equator on a northbound track, I took advantage of Michelle Stone's New Moon invite and celebrated the first full-day of spring by observing from Plettstone in the Sierra Foothills. In addition to our host, other observers for the evening included Stacy, Rashad, Guillermo, "Grimly" Kevin, Jeff Crilly, and Drew (Drue?) from SF.

ObserverBob Czerwinski
DateMarch 20-21, 2004
Observing Time6:30pm to 3:15am PST (UT -8, or 0230-1015 21 March 2004 UT)
LocationMichelle Stone's Plettstone Property, near Mariposa, California
MoonNew Moon -- Just a few hours old
Equipment18" f/4.3 Newt/Dob e/w Telrad and Paracorr
Eyepieces17mm-133x and 12mm-188x TV T4 Nagler; 9mm-251x TV Nagler (magnifications include Paracorr)
FiltersNone in use
Sky ConditionsZenith LM 6.3; average transparency 7~8/10; average seeing 7~8/10 early, 5~6/10 later
Temp/R.H.59-61F/42~49% all night.

Early Saturday morning, the forecasted sky conditions for the Mariposa area appeared somewhat better than that for the Bay Area, as well as for sites further to the north. In general, we experienced mild conditions throughout the night. Clouds could be seen low to the west and south all night long, with skies generally very clear to the north and east. I usually try a Messier run this time of year, but my plan was to spend the night hunting H2500 galaxies in Coma Berenices, so I knew I'd generally be working from the eastern horizon on up to the zenith.

Early-evening conditions were *very* nice; six stars in Orion's Trap, a wide gap in Castor's A-B pair, etc. Polaris' primary component, however, would alternate between a pinpoint and a slight fuzz, so the expected upper-air movement was definitely with us. By 10:00pm the skies had certainly softened, after which I only noted occasional periods of that early-evening steadiness. General transparency remained pretty decent, even though a thin band of cloud would move across the sky from time to time. I snuck in an hour's nap a bit after midnight, but picked things back up a bit later. Cloud cover eventually reduced transparency to the point where my hunt for Coma's H2500 items was useless, but that wasn't until about 3:00am.

The Planets ...

The evening started off with views of the five n*ked-eye planets ... uh, excluding Earth. About 6:25pm, as I swung my 'scope over to Jupiter, Ganymede's ingress was *just* starting. With Jupiter' disk shimmying a bit, the bright Galilean moon took on the appearance of minutely wandering back and forth on the edge for a moment, as if it were trying to make up its mind on which way to go. Once into full transit, I soon lost the moon. Sitting just above the western hills, Drew quickly had Mercury in his 14.5" Starmaster, the tiny planet colorfully dancing around in the eyepiece for all of us to see, but with a definite gibbous appearance. Venus, at about 3rd Quarter stage, was bright and steady .. marching toward it's solar transit on June 8th. Mars, now just a shadow of its August 2003 self, could just be made to show some irregular darkness on the surface, but any further description would just have been a guess on my part. Saturn was absolutely gorgeous ... as usual. No words to adequately describe the Ringed One, even if I really didn't spend much time here. I did take a couple more ganders at Jupiter, first noticing Ganymede's shadow around 7:15pm. My last view of Jupiter (with my non-observing eye) was when said shadow was just about at Jupiter's meridian, Ganymede itself was egressing, and Io's shadow was just coming into view. I completely missed Io's ingress, and I couldn't locate the moon at all during its transit.

The galaxies...

After the planets, I completely ignored any and all eye-candy this night, and just concentrated on Coma's galaxies. Working in RA, I first started with IC 4051 ... which happened to sit right in the middle of Abell 1651, the Coma-I cluster. In the words of Scooby-Doo, "Ruh-Roh." Well, this was very typical of my night. It didn't take too long to get to the general area, marked by a 7th and 8th mag star and relatively bright NGC 4889. Once I had the field identified, and the TheSky on my computer rotated to match the field, I felt like I was shooting fish in a barrel. With a towel over my head to block out all other light, the only issue was that the more I stared, the more I saw. So it was back and forth between eyepiece and computer screen until I'd marked off everything I could easily identify, to include IC 4051. Unfortunately, this is a major problem for me ... as well as for a few others working down the H2500 list (less the H400-I and H400-II items). You may end up identifying a fair number of galaxies, but only a small fraction may actually be on the H2500 list. Well, I guess it's a good problem to have!

The second item on the list was NGC 4015, right on the border of Leo. Again, not too difficult to get to the area, but 4015 was mixed up with about a dozen other galaxies. About this point in time, Michelle came over to take a look in the eyepiece. Looking at TheSky's screen display, Michelle said something to the effect of, "I bet you can identify all of those." And she was right. Took a while, but I eventually nailed 'em all.

And so went my night. I had an absolute blast, chasing after Coma's H2500 faint fuzzies. For once I'd done my homework in advance, so I knew what existed and what didn't, what was duplicated or misidentified, what was in the wrong location, etc. Made things quite a bit easier. I don't know how many galaxies, H2500 and otherwise, I identified. I still need to enter everything into my logs, but the number was definitely up there. I definitely took a big chunk out of my Coma list.

I wanted to chase after three comets, C/2003 H1 (LINEAR), C/2003 K4 (LINEAR) and 43P/Wolf-Harrington, all about 12th magnitude, but never made the time to do so. As usual, I was pretty much in my own little world on Saturday night, engrossed in The Hunt.

For those of you who made it out on Saturday night, I hope your evening was as enjoyable as mine. I certainly want to offer my thanks to Michelle and Paul for their generosity and hospitality.


Posted on sf-bay-tac Sun Mar 21 23:07:34 2004 PT
Converted by report.pm 1.0 Thu Jul 8 17:50:19 2004 PT