Coe April 24/25 2004 -- "naked eye" comets in hill and sky

by David Kingsley

I headed up to Coe last night despite the late moonset, hoping to catch comet Bradfield at dawn when it was predicted to be only half a degree away from comet Tabur. When I arrived around 9 pm, I was surprised to find a new thin gatehouse structure on blocks at the parking lot entry (temporary?), and about 30 cars in the lot. Most belonged to hikers and campers who were elsewhere in the park. There were also a half dozen or more scopes scattered among all the overflow parked cars. I set up near the south end of the lot, hoping to have the clearest view possible of the eastern horizon at dawn. With the moon up and no fog in the valley, skies were pretty bright. However temperatures were pleasant (never below 60), humidity was low (30 to 40%), and there was no troubling breeze or wind during the night. Seeing was excellent and I had some spectacular views of both Jupiter and the moon in my 14.5 inch Dob between 10 and 11 pm. I then poked around at some galaxies in Virgo, slept for a few hours, and got going again about 3 am on objects in Scorpio and Sagittarius.

Around 4:30 am, I started getting ready for the coming comet show to the east. It was immediately obvious that the horizons would be a problem. The Bradfield/Tabur duo was rising somewhat north of east, putting it behind a low ridge to the northeast from the Coe parking lot. The extra elevation in that direction meant that the comet duo would probably not clear the horizon before dawn twilight. Comet 2002 T7 Linear was rising more to the east, at a point just further enough along the ridge that it looked like it might be possible. The big Dob was fixed at one position in the lot, so I also set up a 105 mm refractor on an alt-az mount, and carried this around the parking lot looking for the best notches along the tree line on the eastern horizon. Between 4:45 and 5 am I watched the stars of Pisces rising up out of the trees beneath the square of Pegasus. An extra fuzzy spot appeared in the 6x30 finder slightly after 5 am, and a quick check through the scope confirmed Comet LINEAR. I looked at the comet with a bunch of different eyepieces in both the 4 inch refractor, and about 15 minutes later, in the 14.5 inch Dob. This low in the sky, the comet appeared as almost all core and halo, with hardly any tail visible. The comet was as bright as the mag 5 ish field stars in the finder, so it is still on track to be a great object as it gets higher in the sky in May. If you haven't seen it yet though, don't feel bad about waiting a couple weeks for it to be in better position. A great comet needs a great tail, and this one is not yet a great view for Northern observers.

I had the coordinates for comet Bradfield so went ahead and entered them into the Sky Commander when the approaching dawn made the sky to bright to starhop. A quick check through the eyepiece showed that the Bradfield position was still buried several degrees into the hillside around 5:25 am. I checked back into the eyepiece from time to time while chatting with the only other observer who was still up. He was also from the Palo Alto area. Last night he had gotten his last two Messier objects, finishing the Messier list. Sorry I didn't catch your name, and congratulations again on finishing a great first observing project! By 5:45 am or so, the sky was bright with civil twilight, and the eyepiece view was white as milk as the Bradfield/Tabur sky position finally cleared the tree and ridge line.

Ah well. Although I wish I had had a better horizon to the east/northeast, I'm still glad I went. I learned some useful SkyTools features in the course of preparing for the night. (Great charts and observing list features if you have the patience to endure one of the most non-intuitive interfaces I have ever seen). The early evening views were much better than I would have had from my backyard. Dawn was beautiful from the hilltop. And I enjoyed packing up in the light and driving home with a couple hours sleep during the night. Despite having been to Coe many times over several years for both hiking and astronomy, I think this was one of the first times I have ever driven down the hill when it was actually light out.

Posted on sf-bay-tac Apr 25, 2004 16:05:43 PT
Converted by report.pm 1.1 Jul 10, 2004 19:26:51 PT