Monday, December 10, 2007 - A Whale of a time at Dinosaur Point

Albert Highe

I left home just after 2PM in order to avoid much of the traffic. I had a pleasant, relaxing drive down. The sky was mostly clear. The temperature reached 61°F while passing through San Jose, ten degrees cooler than the same time a week ago.

I arrived at Dino about 3:45PM. The air was calm and the skies clear. The lake was like glass and windmills on the nearby hills were frozen sentinels. The temperature was 50°F.

It took only a couple of minutes to set up the 13" f/4.5 grab-and-go "blue" scope. The OTA is short enough to fit in my van fully assembled.

By 5:30PM, stars started popping out. I collimated the scope and aligned the finders. The temperature had dropped to 41°F with a relative humidity of 75%. The skies were completely clear. There was no wind, but it already felt cold. The double-double showed a pretty good split with the 9mm Nagler T6 (165X). I used my 7mm Nagler T6 (212X, 1.5 mm exit pupil) during most of the night.

By the time I bagged a dozen new galaxies in Cetus, it was 7PM and the temperature had dipped to 39°F with a relative humidity of 79%. At this rate, it might be a short night. But I was still optimistic. My heavy boots and multiple layers were on. The chemical toe and hand warmers were kicking in, and there was no wind. I was comfortable

Interestingly, a half hour later, the temperature had increased to 41°F, but resumed its downward trend an hour later. By 8:30PM, the temperature was back down to 39°F, with a relative humidity of 76%.

By 11:15PM, the temperature dropped only another two degrees, to 37°F, and the relative humidity had climbed to 90%. The air was still calm, and all optics remained dew-free. My observing table began to feel a little clammy, and stars had begun to bloat. The fifth star in the Trapezium was blurred all of the time. So, I switched to low power and visited some eye-candy before packing up at 11:30PM. I had enjoyed over five hours of observing in good conditions.

I logged observations for over 60 objects, most of them observed for the first time. All but three were in Cetus. The others were swimming with Pisces, just beyond the border.

Below are a few highlights - swimming partners sharing the field-of-view:

NGC 899 - Approximately 0.6' x 1.0' oval with fairly large, brighter, central area that just disappears with direct vision. Easily held steadily with averted vision.

IC 223 - 5' to the NNE of N899. Smaller oval, about half the diameter and length. Held steadily with averted vision.

NGC 7808 Unremarkable small circular halo with a diameter of about 0.6', and smaller, somewhat brighter core. Held steadily with averted vision.

MCG-2-1-12 Observation notable only because I also saw this nearby oval galaxy, approximately 3' SW of N7808. Very small oval halo, about 0.2' x 0.4', with faint stellar core. Held steadily with averted vision despite 11th magnitude star 0.75' to the west.

NGC 34 - Small circular galaxy about 0.4' diameter, visible steadily with averted vision. Irregular outline? Bright, smaller core was visible with direct vision.

NGC 35 - Smaller galaxy approximately 5' north of N34. Appears to be about half the diameter and nearly circular. Had a small, brighter core. Held steadily with averted vision.

NGC 61A (= MCG-1-1-63)

NGC 61B (= MCG-1-1-63)

At first glance, NGC 61 appeared as an elongated haze about 0.4' x 0.6' oriented NNW-SSE. After a little more careful study, I resolved two stellar cores separated by a mere 20". Their cores were surrounded by nearly circular halos that appeared to touch or just overlap. N61A's halo was about 50% larger. I held the pair steadily with averted vision, but resolved them into two clumps about 75% of the time. It was satisfying to observe these details before confirming them against a DSS image the next day.

NGC 829 - Small oval halo approximately 0.3' x 0.6' with small, stellar core. Irregular outline? Held steadily with averted vision. Brightest portions just disappeared with direct vision.

NGC 830 - Similar to N829, and 4' ENE of it. Stellar core held with direct vision. Overall, appeared brighter and slightly larger than N829.

NGC 833

NGC 835

NGC 838

NGC 839

A nice tight grouping of four, small, relatively "bright" tadpoles. (I'm taking artistic license in order to maintain the aquatic theme). All had small, roughly oval halos easily visible with averted vision, and bright cores visible with direct vision. N835, the brightest of the four, appeared somewhat larger and more circular. N833 and N835 formed a close pair 0.8' apart on a line running approximately E-W. N838 appeared nearly circular, lying along the same line as the N833/N835 pair, approximately 3.5' east of N835. N839 appeared more elongated, 2.5' SSE of N838. The group appeared to wrap around a 10th magnitude star, making the group easy to locate. This group should be visible in quite small scopes.

NGC 943

NGC 942

This is a close pair of small galaxies, with cores 35" apart. Orientation appeared approximately N-S. Indistinct halos appeared approximately circular, and overlapping. Each had small, brighter cores and faint stellar nuclei. Overall, N942, to the south, appeared brighter. However, I held each steadily with averted vision.

IC 230 - In the same f.o.v., just 5.5' west of the above pair, I found and held this very small oval 60% of the time with averted vision.

NGC 945 - Moderate size oval halo appeared approximately 1.0' x1.3', held steadily with averted vision. Small, slightly brighter core just visible with direct vision.

NGC 948 - Smaller oval halo, approximately half the size of N945, and 2.5' NE of it. Also dimmer, but held steadily with averted vision.

NGC 1076 - Bright core with stellar, or very small, brighter nucleus. Oval halo, approximately 0.5' x 0.9', with indistinct edge. Held with direct vision.

MCG -3-8-5 - Much smaller oval, approximately one-fourth the length of N1076, and 6' ESE of it. Despite lying 2.5' south of a 10th magnitude star, held steadily with averted vision.

NGC 1065

IC 253

These galaxies appeared to be similar (small and circular, with near equal brightness), positioned 2.6' apart, and oriented N-S. To my eye, IC 253 to the north, appeared a little brighter. It is surprising an observer would detect N1065, but overlook nearby IC 253. I had little trouble spotting both and holding each steadily with averted vision. IC 253 just disappeared with direct vision.

Comet 17P Holmes

Recently, Bob Jardine mentioned that this comet reminded him of a trilobite, so I had to take a look. It was well overhead just before I left, and easily visible with the unaided eye - brighter and larger than the double cluster in Perseus. I used a 27mm Panoptic, providing 55X and a field of view of approximately 1.25°. I immediately saw the structure Bob had described. A somewhat flattened semi-circle, approximately 1° wide, with a well-defined sharp edge, outlined the "head". A bright "bar", about 10'-15' wide, lied along the central axis, almost 1° long. Unlike the trilobite, the bright bar didn't extend all the way to the sharp-edged "head", and its width was more uniform. The trilobite appeared longer than wide, its tail extending beyond the field-of-view. It was difficult to tell where it terminated. There was no sharp outline. Thanks for the mental image, Bob.

It was another memorable solo observing session at Dino. It is always an unexpected pleasure to have such good conditions coincide with New Moon during the winter.

Albert