Wednesday, April 13, 2005

Emptying the Cup!

Last night my daughter Mimi, boyfriend Jeff and I joined Peter Natscher for a short night of observing on Coulter Row at Fremont Peak. It has been forever since I've observed from that location. I can report that the site is still quite good, and has seen some nice improvements since my last visit - new restrooms up at the overlook, and good pavement. I brought my 18" f/4.5 Obsession and 10" f/5.7 CPT, Mimi got to use the smaller scope to show her boyfriend some highlight objects. It was a short night for Mimi, as the cold got to her, and she was gone by eleven.

I decided to go to the Peak - my annual trip - and try Coulter as it is protected somewhat from the wind, has a very good southern horizon, and Peter was going. I had not seen him since Shingletown last year. I enjoyed the evening - Peter and I were swapping views - he had several nice galaxy groups during the night.

I was continuing my Herschel 2500 project. Man, what a task. My hat's off to folks like Gottlieb and Czerwinski, who've logged that many objects and (in Steve's case) more. I've been at this off and on for a very long time. Last night I went after objects in Crater, which was among the springtime constellations that are so difficult to get clear skies for. As noted in Peter's report, temps were chilly, dropping into the mid 30's, but other than my fingers, I was not cold.

Here are the objects I observed:

NGC 3081Galaxy type SAB, mag 12.85, SB 13.2, size 2.1'x1.6': I began hunting this target (actually in Hydra) in the late twilight, and found the location difficult. Using Alphard (Alpha Hydrae) and making a right angle with Lambda Hydrae, I ended up using the naked eye pair of stars SAO 177840 and SAO 177866, which are 23' apart, to hop via my 10x70 finder to the correct position. The galaxy was dim, but had a bright non-stellar core surrounded by a dim halo disk. It is located off a nice chain of six stars to its NE. There may be some elongation NNW/SSE.
NGC 3892Galaxy type SO, mag 11.5, SB 13.4, size 3.0'x2.2': I hopped from Alpha Crateris to Delta, and out NE to mag 6.2 SAO 156896, which made the position easy to locate. The galaxy is small, oval with some elongation E/W. It contains a bright core with a dim stellar point.
NGC 3956Galaxy type Sc, mag 12.1, SB 13.3, size 3.4'x1.0'. This one appeared as a dim slash ENE/WNW with even brightness throughout. There were two pair of stars of equal PA to the NNW that helped locate the galaxy. I found this one going form Delta to Gamma Corvi and down to mag 5.2 SAO 157042, and the galaxy was just beyond, barely inside Crater's border.
NGC 3962Galaxy type E2, mag 10.7, SB 12.6, size 2.6'x2.2'. This was one of the tougher locations, without a bright star nearby. I went from Gamma Corvi to mag 5 SAO 156998, then north, and hunted around a bit. There were two bright stars nearby to the S and SW that helped mark the location, but the galaxy itself was quite bright and obvious in the eyepiece. It had a stellar core with a bright inner disk that diffused abruptly out to a dim outer disk.
NGC 3981Galaxy type Sbc, mag 11.3, SB 13.8, size 5.2'x2.3'. Very near the location of NGC 3956, this very long galaxy had an even brightness and was in a WSW/ENE position.
NGC 3456Galaxy type SBc, mag 12.4, SB 12.9, size 1.9'x1.3'. Located at the western extreme of Crater, it is easy to locate star hopping from mag 3.1 Nu Hydrae. It is small, very dim and elongated E/W with a dim star just to its E. There was no detail. But, I do like sequential NGC numbers like this one (my favorite is NGC 6543).
NGC 3571Galaxy type Sa, mag 12.1, SB 13.2, size 3.0'x1.0'. In an easy position in Crater nearly mid-point between Alpha and Gamma. This appeared to be edge-on, had a bright core with a near stellar nucleus, and seemed quite elongated E/W 5x2.
NGC 3715Galaxy type SO, mag 13.9, SB 12.7, size 0.8'x0.5'. At first I thought I was just dyslexic and had transposed numbers with the prior object, but no, this was really the next on my list. It is located very close to NGC 3571, on the same line toward Alpha Crateris. Small, bright and round, with a stellar core.
NGC 3667Galaxy type Sbc, mag 12.7, SB 12.4, size 1.5'x1.0'. Very easy to locate going from Alpha to Delta, then another 1.5 degrees further. This galaxy appears oval and even brightness, elongated E/W. Bumping up the power brought out NGC 3667A, much dimmer, but about the same size as 3667 which is to its W. 3667A forms a right angle with 3667 and a close star. 3667A is elongated NE/SE and is separated by only 1'.
NGC 3955Galaxy type SO, mag 11.9, SB 12.9, size 2.9'x0.9'. I used mag 3 Epsilon Corvi and mag 4 Alpha Corvi (yes, you read those mags correctly) to form an isosceles triangle to locate this target. This was a nice view, very elongated N/S with a pronounced bright large central bulge. A very slight hint of a stellar core - the southern extent of the galaxy seemed to be disrupted, or perhaps it is a barred spiral - there seemed to be hints of arms curving back of the ends of the extensions.
NGC 3957Galaxy type SO, mag 11.8, SB 12.5, size 3.1'x0.7'. Nice! Bright, very elongated about 5X1 N/S, with a dark area in the S extension. In an easy position to locate, Delta to Gamma Corvi, to SAO 157042, and a bit west - three stars to the galaxy's NW help mark the field.
NGC 3732Galaxy type EO, mag 12.5, SB 12.8, size 1.2'x1.2'. Too easy to find, just off mag 4.7 Theta Crateris. It is small, round and has a stellar core in a bright nucleus. A bright star sits close to its W.
NGC 3508Galaxy type Sb, mag 13.2, SB 12.9, size 1.0'x0.9'. Located very close to a pair of naked-eye stars just N of Alpha Crateris. It appears irregular, elongated SSW/NNE, possibly larger on the SSW end. It has a star embedded in the NNE end. I wonder if this galaxy is disrupted?
NGC 3951Galaxy type SBO, mag 13.1, SB 13, size 1.3'x0.8'. Easy hop off of Delta Crateris, however, this proved a difficult object. It was odd that it was *just* visible in my 20 Nagler (100X), but not in the 12 or 7 Naglers. As such, the best description I can attach is, non-descript!
NGC 3661Galaxy type SO, mag 14, SB 14.2, size 1.7'x0.8'. Great location! Go from Alpha to Delta and just beyond - really easy. The galaxy is elongated SSE/NNW with a bright core containing a dim stellar point. I felt there was some mottling. An easy bright chain of three stars sits very close to the galaxy's south.
NGC 3734Galaxy type Sbc, mag 13.7, SB 13.9, size 1.4'x1.0'. I used Iota (24) Crateris as the jumping off point to hop to this target. It was extremely faint and yielded no detail. I could see it only in the 12 Nagler and even then, only by jiggling the telescope, which showed a round ghost coming in and out with averted vision.
NGC 3791Galaxy type SO, mag 13.7, SB 13.8, size 1.3'x1.0'. This was a fun target, and my last for the night. Alpha and Delta to hop to mag 4.7 Theta Crateris, then star hopped to the galaxy from there. The galaxy was small and round, averted vision showed a stellar core. It was easy to pick out a low power. Three other galaxies in a tight knot - NGC 3771, MCG 1-30-17 and MCG 1-30-18 break up nicely at high power (280X), although the two MCGs are very close together. One oddity was that NGC 3791seemed to have a double nucleus at high power.

That was it for the night. I had finished off the objects in Crater, emptied the cup of H2500 objects.

Before finishing, I will say, as I do each year, off of Highway 101 along 156 then up San Juan Canyon Road is one of the most beautiful I know of in spring. It is verdant green, there are wildflowers on the shoulders of the road, and cattle, horses, rabbit and wild turkey around the turns. The view of the coast from Fremont Peak is a treat.

I also found that it was not too bad observing galaxies with a 5+ day old moon. Earlier in the day I wrote Attilla Danko, ex-bay area resident (used to attend our Lassen Star Parties) asking him about an additional feature for the clear sky clocks. I wondered if there could be a way to quantify magnitude loss for various percentages of the moon - for its phase, and for certain degrees off the moon - and perhaps model in transparency as well. This would help tell observers if the targets they are interested in would be visible, or "mooned" out on a particular night. I did not mind having the moon up... I'll do it again. I might even go back to the Peak again before next year!

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