San Antonio Valley views in a cloudless sky 12/16/1998
By Bruce Jensen

On Wednesday, December 16, 1998, Doug Hudgins and I took our dobs up to San Antonio Valley for a midweek observing session. From my car on the way up, as I watched the sun sink behind the hills I noticed a light phenomenon that I had never seen before, despite taking notice of these things whenever possible: At the point where the sun shone but a pinch above the horizon, there were multiple concentric rainbow-colored halos around the sun at very small angles, in fact there may have been three distinct rainbow-hued rings within five degrees of the sun. It was a remarkable sight, a spectre I have seen only once in 39 years, and quite lovely; I hope that I shall be able to see this again before another 39 years passes.

Not a single cloud was to be seen, in itself also remarkable, considering the run of less-than-perfect skies we have been having for nearly a year in California. The wind had subsided significantly from the previous night, with only gentle breezes from the north drifting across the broad expanse of the valley. Some moisture was barely tangible in the air, promising dew (or, as it turns out, frost) at some point during the evening. Seeing was mediocre at best during the evening, and most often quite unsteady.

The scope of the evening was a Starmaster 18" F/4.5 dob, collimated (as always ;-) to perfection. The eyepiece used for finding objects was a 22mm Panoptic for 92x unless otherwise noted, and the source of magnitudes for objects was Sky Atlas 2000 Companion, also unless otherwise noted. Doug, a NASA Scientist, generally accomplished observer and all-around fine fellow, on this evening brought along his 17.5" homebuilt dob with mounted Edmund Astroscan to search mostly for planetary nebulae, with considerable success.

The skies at SAV aren't what they used to be, with the expansion of towns like Morgan Hill and Gilroy to the south, and the light domes keep growing noticeably year by year. Still, the sky was dark enough to search fairly far south, although in a truly dark sky many of the more difficult objects observed this evening are "just cruising" for this telescope. The first target was the NGC 1052 galaxy group in Cetus, the flagship of which is NGC 1052 at mag. 10.6. Others in the group include NGC 1035, bright and edge-on at mag. 12.2; NGC 1042, faint and large at mag. 11; the NGC 1048 pair (A & B) at a combined magnitude of 14.5, at the limit of visibility; NGC 991, at mag. 11.7 faint and medium size; and NGC 1022, modest in size with a bright nucleus at mag. 11.4.

Also in Cetus but outside of any identified group, we viewed NGC 895, a galaxy of modest size and bright nucleus, mag. 11.4 (a companion, NGC 894, was not seen). NGC 681 at mag. 11.8 was fairly compact and somewhat lens-shaped, and the SA 2000 Companion suggests that it looks like a small version of M104 (the Sombrero) but the seeing prevented the use of high power to verify this alleged characteristic. Finally, NGC 701 at mag. 12.2 was seen in its pairing with IC1738 about 5 arcminutes south, at mag. 14.5 the faintest individually-seen galaxy of the evening. This latter observation, as well as some others during the evening, further convinced me that I need to get a more comprehensive star atlas, because many of the objects in reach of an 18" scope simply are not in SA 2000.

Next, for variety, I searched out a few planetary nebulae. With Doug's help and the aid of his Uranometria atlas, I was "able" to track down Abell 2 (PK122-4.1), a moderately-sized mag. 14.5 PN in Cassiopeia at 92x/290x using an O-III filter. Appearing very faint and amorphous under this sky, this find was nonetheless very pleasing. I was also pleased with finding the 12th-magnitude Minkowski 1-7, for which I searched unfruitfully the previous night - again, Doug's assistance (and his atlas) was invaluable. The soft seeing prevented the type of view presented by Jay McNeil in his recent Sky and Telescope article on planetary nebulae, but the O-III filter really brought this object out, and some elongation was notable when viewing at 225x and above.

To round off the planetaries, I first swung the scope toward the neighborhood of Beta and Pi Aurigae to find IC 2149, a very bright 8" planetary that "blinks" beautifully using an O-III filter. At 290x it showed a small, possibly irregular disc. Finally, the scope was aimed for IC 418 in Lepus, another small bright PN that presents a diminutive ring-shape at fairly high power.

To conclude the evening, the area near the Eridanus/Orion border was viewed in some detail, starting with the NGC 1625 group near star 48 Eridani. NGC 1625 is a fairly bright (mag. 12.4) elongated spiral, and also in this group, partially "surrounding" the star are two more galaxies, NGC 1618 (mag. 12.7) and NGC 1622 (mag. 12.5). The trio, juxtaposed so closely to the brilliant star, make a fine sight at low power.

As the dew/frost began to settle, the race was on to nab as many galaxies as possible in this area before everything became wet or frosty. In the same area near the Eridanus/Orion border, I found the following objects:

Frost on the car, the eyepiece case and the secondary cage, along with dewy eyepieces and work at 7:00 AM, convinced me to pack it in at 10:40 PM. Still, it was a wonderfully satisfying evening, and here's hoping that, unlike 1998, the New Year will give all of us many more nights as lovely as this one.