Short Night at SAV, March 7, 1999

by Bruce Jensen


Being a meteorologist, a time there was when I would thrill to an endless parade of clouds and rain for a couple of weeks in a row, watching the changing play of patterns of light and dark and gray and blue across the dome of the sky, with occasional rainbows and lighting to add welcome accent. In between would come stretches of sparkling winter and spring days, with half of my world a deep cerulean blue by day, and an even deeper void of velvet blackness at night spattered with the glimmer of a thousand remote suns.

Then came El Nino and his smaller but equally tenacious sister, La Nina.

Since then, the parade of earthly aqueous nebulae has extended from weeks to months, and the sparkling days seem to be a thing of the past. So, when the rare clear day teases with tenuous promise of productive starwork at night, it seems critical that I should jump on it. Such was the case Sunday evening, March 7, despite the fact that the 5:15 alarm would ring on time the next morning. Desperate times call for desperate measures.

I trundled the 0.457 (18" for you English system fans) up to San Antonio Valley (SAV) for a short night of deep sky work before the rise of the moon about 11:30-ish. Even at 4:15 when I left the house, the high clouds were already poised on the horizon, but I hoped against hope that they would stay put to the west for at least a few hours. At 6:00 PM I arrived at SAV, with my friend Paul Sterngold arriving a few moments later with his astrophotography gear. We drove on back to our lovely viewing site and set up. For a few hours, the sky did cooperate - mostly. At best, Paul estimated the limiting magnitude at 6.3, which was probably about right for the portions away from the Bay Area sky glow. The data for the following observations are taken from the Sky Atlas 2000 Companion and the Uranometria Field Guide.

Between the cirrus wisps, the sky was quite good. I started off with NGC 2610, a pretty big planetary nebula (PN) in Hydra at 37" diameter. At magnitude 12.7 it showed a faint small disc with a small darkening in the center that suggested a ring shape. Working westward, over to Puppis and NGC 2539, a bright magnitude 6.5 open cluster (OC) immediately next to 19 Pup, a bright star. This cluster is quite lovely and rich, a condensed group of 50 stars with a distinctive if irregular shape. Looking for all the world like a fuzzy granulated glow in the binoculars, one wonders why Charles Messier would not have included this in his list, because its proximity to M46 and M47 suggests that he at least once trolled in this part of the celestial sea for cometary catches.

Some nearby galaxies were next. NGC 2525 was a very interesting moderately faint spiral galaxy of considerable size and extent, magnitude 11.6 with a fairly bright nucleus at 290x. It has a distinctly "crabby" appearance owing to its sprawling spiral arms - a wonderful object. Nearby was NGC 2517, a magnitude 11.8 galaxy with a very bright center and faint outer regions. Its appearance was starlike enough to make it hard to spot at first, but again, 290x confirmed it as a hit. After a quick look at M46 and the little superimposed planetary NGC 2438, which at high power looked truly lovely, I hopped to a very faint small planetary nebula PK231+4.1, a small disc 30" in diameter that, at magnitude 15 visual, was completely invisible without an O-III filter. With filter attached, however, the little even disc glowed faintly against the sparse starry backdrop. This ended the tour of this part of the sky which was by now seeing some cloud cover.

Then, up to Leo and clearer skies. First came the NGC 3193 group that includes NGCs 3185, 3187 and 3190. This group, aka Hickson 44 (the brightest of the Hickson groups) and Arp 316, includes a range of magnitudes from 10.9 at the brightest to 13.4 at the dimmest (3187). It is a lovely low-power group, just stretching across the entire 0.6 degree field at 145x. About a half degree to the northwest was noted another galaxy, MCG+4-24-22, which at magnitude 14.1 was fairly faint but reasonably obvious - a nice find.

A few more galaxies would bring the short session to an end, and one would be a real find for this location. NGC 3221 was seen as very elongated magnitude 13.1 streak, actually a spiral galaxy with a substantial tilt to our line of sight. NGC 3177, at magnitude 12.4, has a bright nucleus and is quite near magnitude 14.8 UGC 5629, which was not readily visible.

Then came the penultimate and ultimate finds of the night, which provided a fitting (if too early) end to the evening's viewing. NGC 3216, a fairly dim galaxy, was noted in the Uranometria Field Guide to have within 5 arcminutes of its disc, another galaxy, UGC 5597 at magnitude 15.5. After the first look in the eyepiece at the right location and seeing nothing, I went to the Guide to check the direction and specifics on this faint object. Paul took a short peek, and armed with information and skill quickly picked out the faint glow just a bit to the west. Another look confirmed this object, fairly easy with averted vision, but seeming to come and go with the rapidly changing sky conditions - the clouds were coming in force. It was nonetheless a pleasing end to the session, and a good indicator of what this site may be capable of delivering in a large scope when the sky conditions remain more favorable.