by Steve Gottlieb
Robert Leyland and I took advantage of a clear window between fronts on Sunday and met after sunset at Lake Sonoma. The sky was very transparent (6.0-6.5 limiting mag), but seeing was on the soft side in the wake of the system that just passed through northern California.
I wanted to get a good look before Linear 2000/WM1 dove towards the southern horizon and it didn't disappoint although it's easy to be jaded after Hyakutake and Hale-Bopp with merely "very good" comets. After dark adaptation, the comet was just visible naked-eye as a fuzzy glow and even seemed elongated at times naked-eye. A good view of the tail, though, required my 10x50 binoculars or even better through my 17.5" scope at 63x (31 Nagler) as it extended fully across the 1.3 degree field.
The next three hours was spent working through some faint galaxy groups in Cetus, Eridanus and Fornax. One interesting find was ACO (Abell-Corwin-Olowin) S301 in Fornax, located about a degree southeast of NGC 1097 (one of the best galaxies in Fornax!) at 02h 49m -31d 15'. The cluster is found in a supplement to the southern extension of the familiar Abell catalogue of galaxy clusters (published in 1989) and includes three IC galaxies. The new version of the Uranometria plots the cluster as well as the IC's and several nearby MCG and ESO galaxies.
IC 1860 is the largest and brightest in ACO S301 cluster, although only 30" in diameter. A 12th magnitude star is less than 2' NW. The second brightest in the cluster is IC 1859 about 6' WNW and 1' following a mag 13 star. It appeared round, 20" diameter with no noticeable core. The faintest in the trio, IC 1858 was found 8' SW of IC 1860. It seemed slightly elongated N-S, ~25"x20", although the DSS shows fainter arms extending N-S which I missed.
After spending most of the evening hunting low in the southern sky, I finally moved up to Taurus to an exotic object -- BW Tauri at 04 33 11.1 +05 21 15. Although it carries a variable star designation (discovered at Harvard College by Harlow Shapley and Hanley in 1940 with a magnitude range of 13.7-16.4), this is a distant galaxy with an active nucleus and a redshift of .033 - implying a distance of roughly a half billion light years!
In 1959 it was rediscovered as radio source, 3C 120, but due to poor spatial resolution of the radio telescope, there was no optical identification at that time. Finally, it was picked up again in the 1960's by the galaxy surveys based on the Palomar Sky Survey (UGC and MCG). When the relatively high redshift was finally measured, this galaxy became a prime target for the professionals -- NED gives several hundred journal references and BW Tauri is considered similar to a low-luminosity quasar or Seyfert galaxy. Visually, it appeared like a fuzzy mag 14 star (core), with a very low surface brightness halo, perhaps 20".
By 10:00 when I started tearing down for the 80 minute drive home (about the time we generally start observing during the summer months), we had already observed about three and half hours and I had filled several pages worth of observing notes!