Post-it-notes at Henry Coe

by David Kingsley


I arrived at Henry Coe a little before 7 pm Friday night 3/3/00, for what turned out to be a great night of observing. There was a fairly strong wind when I first arrived, but it died substantially over the next hour or so. I noticed lots of white scatter in the sky near the sun while driving down, and the moisture in air probably hurt transparency compared to the best nights at this location. However, temperatures were pleasant (mid 40s most of the night), and there was not much dew (in contrast to conditions at the beginning of February, when I also got in several hours of good observing, but under both colder and wetter conditions).

All the rain in the intervening weeks had given me more time than usual to plan an observing session. I have been working on the Hershel 400 list for the last 15 months or so, and have printed lists of all the objects for various months from the TAC web site. I usually start looking up objects from this list using either Astrocards or the Night Sky Observer's Guide, trying to concentrate on objects within a single constellation. This works fine, but often involves lots of page turning or card shuffling while looking for objects and finder charts.

This month, I spent a couple of rainy evenings adding small bits of yellow post-it notes to the charts of my Herald-Bobroff Astroatlas for the remaining H400 target objects. This made it extremely easy to see the best search strategy for a whole bunch of different objects simultaneously. When I had seen and logged an object, I would then simply pull the sticky note off the chart, gradually clearing whole areas of targets. This strategy worked great for finding nearby objects along the borders of different constellations, and for finding nearby objects that are often listed at widely different parts of a list

This simple change in procedure allowed me to log about 10 objects an hour instead of my usual rate of 5 or so. That is despite the fact that I was still making simple sketches of most of the objects, and taking notes on size, brightness field orientation, etc. It helped that I was working primarily in Ursa Major, a region where there is a dense selection of interesting objects on every chart. Nevertheless,the 41 new objects and 73 total objects for the night is probably the most new objects as I have ever seen in a single observing session. I was pleased to be able to make the most out of a rare good observing night and I will try the post-it note strategy again in the future.

Someone asked about the HB atlas recently on TAC. One of the nice features of the atlas is the relatively large number of stars on the most detailed charts, and the amount of information provided about each object. I have a SkyAtlas 2000 but virtually never use it because it doesn't provide enough stars for me to find many of the objects I am looking for, and provides very little information about the objects. The HB atlas shows the orientation and separation of double stars, and encodes lots of information about clusters, galaxies, planetaries in the symbol for the object. I find it particularly helpful to instantly see where all the doubles are and what the approximate separations are at a glance, and to see a rough estimate of the brightness of all the deep sky objects on a chart. This provides for lots of little interesting side trips on the way to the Hershel 400 objects, helps me gauge the likely visibility of an object in a 7 inch scope, and greatly enhances the fun of touring a particular area.

Since it was a long night, I will only mention my favorite new objects of the evening. The diversity of galaxies in Ursa Major was stunning, even when viewed with a relatively smaller aperture Dob (7 inch Starmaster Oak Classic). I particularly liked:

3079, a very elongated galaxy with high surface brightness,

3184 an obvious puff in a pretty star field with hints of mottling and an embedded star on the northern side of the galaxy halo,

The 3893, 3896 galaxy pair, both visible in the same eyepiece field. 3893 had a bright core, hints of structure, and a star in the halo that would blink on and off neatly with averted and direct vision

4088 and 4085, two obviously elongated galaxies with contrasting brightnesses and orientations also visible in a single eyepiece field.

4111 (Ursa major- Canes border). Probably my favorite for the night. The 4111 galaxy is a highly elongated needle shaped object with a bright core located just SW of a nearby pretty double star. The extent of the needle, and the visibility of the double star companion, blinked on and off dramatically with averted and direct vision, a very pretty effect in the 7 inch scope.

The best new double star of the night was eta Gemini (not far from M35). The magnitude contrast between the primary and secondary was striking, and worth a look if you haven't seen this one before.

Clouds rolled in between 2 and 2:30 am, finally putting an end to the romp through the skies. Despite less than ideal seeing and transparency, this was one of the best observing sessions I have had in months. When I got home about 4 am, I was surprised to see Scorpio, Cygnus, and Aquila rising in the east. Summer and more reliable skies can't be far behind.