Observing Notesfrom the Tuckahoe IrregularsThe Tuckahoe campground is now open, and the gates of the Park are no longer locked at night. I arrived at the field about 7:00, to find Dan Kidwell putting the fine touches on his setup. I was out of practice, so my setup and alignment took longer than its usual 25 minutes. Eventually, North was nailed down, and by the time the piping frogs had acoustically buried the honking geese I was ready to go. It wasn't yet eight o'clock, and the sky between Leo and Virgo was hidden in the brighter-than-average eastern haze. So I began with some easy objects in the darker sky to the south. The area above Canes Major has a number of open clusters catalogued by Messier, and I quickly located M48, followed by the nearly adjacent M46 and M47, all of which were easily seen. Unfortunately, I forgot about the small planetary NGC2438 visible with M46, and so did not look for it. I finished up with M93, close to the spine of Canes. At 8:30 Leo's tail was still partly in the murk, but the rest was high and clear; so I located the galaxy doublets M95 and 96, and M65 and 66. 95 and 96 fit into the field of my Pentax 40mm eyepiece, and 65 and 66 were easily circumscribed by my Pentax 21. The discussion of contrast-enhancing filters at the club meeting on Tuesday suggested that I add my Orion Skyglow filter to the optical path to see whether the filter made it easier to spot faint galaxies. After looking at a few of Leo's, I determined that the filter darkened the background sky enough that small galaxies with an overall magnitude of 10 or brighter seemed easier to spot with the filter on a typical Tuckahoe night. Small galaxies with higher magnitude numbers did not seem to have the power to punch through both the thick atmosphere and the light reduction of the filter. I finally looked for Vesta. It was easy to locate from the photo on the NASA Web site http://science.nasa.gov/ppod/y2003/02apr_vesta.htm and was bright enough to see with my 8X binoculars. In my telescope using the Pentax 40, it appeared as a steady, yellowish star. I tried my 10.5 eyepiece to see whether Vesta was large enough to discern a shape, but the flare from its brightness in the eyepiece masked any shape I might have seen. My calculator says that a 275-mile object at 250 million miles should appear around 2.5 arc-seconds wide. I guess that was too tiny on Wednesday night, although on good nights I can split double stars close to that number. During breaks in my own viewing, I'd taken looks through Dan's telescope, first at a faint pair of interacting galaxies in the south, and later at the tiny blue-green Cat's Eye planetary. Aircraft and satellites cluttered the sky as usual, and I watched one medium-bright meteor pierce Ursa Major. We watched a strange, three-degree-wide green glow appear about nine o'clock in the southern sky and fade about fifteen minutes later. Most likely it was a high-altitude sounding rocket from Wallops; they disperse glowing material into the upper atmosphere for high-altitude weather analysis. After Vesta I found the bright globular M3, and ran it through all my eyepieces. I saw detail, but my eye needs to be "glob-trained" again. I finished up my deep-sky observing in the north, with a series of good views of M51, which looked best with my Skyglow filter and my 21mm eyepiece. Then I swung the C8 across the Dipper's handle to look for M101, and surprised myself by finding it easily using my Pentax 40 and Skyglow. Before now I've only been able to find this wide, diffuse galaxy about 50% of the time, but on Wednesday its hazy core was easily discernible against the filter-darkened sky. At 10:30 I spent 20 minutes examining Jupiter, so close to the Beehive that in binoculars its light overpowered some of the cluster's nearby stars. I finished up with my Pentax 10.5 and my "Moon" filter, which reduced Jupiter's brilliance enough that I could see color and texture variations in its two darkest cloud bands. I packed up my equipment and left at 11:30. The Tuckahoe Sky Clock had been just about dead on. It had been an atypical Spring night for the ball field. There was moisture in the upper air, judged by the height of the horizon glow, but there was no dew. There were no clouds, no moon, no mosquitoes, and it required only a sweater to be comfortable almost til midnight. I didn't search for anything overly difficult, but I easily found everything I tried to observe. As it turned out, Dan and I had the ball field to ourselves; no other intrepid observers were able to get there on short notice in the middle of the week. It was a shame that more stargazers couldn't have taken advantage of the good night. |