Fremont Peak 4/18/2009

Dave Goggin

There was a big school group so the first couple hours were spent showing crowd pleaser items and answering questions.

Weather was great. Reasonably warm with only occasional light breezes. Seeing was OK early but by 3:30am when the moon came up had improved to excellent with very little visible star twinkling.

This was the first time I had checked the actual sky darkness up there. Early in the evening, zenithal darkness was 21.06 - 21.1 by the meter, but by midnight and later had improved to the 21.25 range. I was surprised that even after the moon was well up, readings close to 21 were still being taken at zenith.

Compared to the 19.4 usually read at Land's End on good nights, all this was quite impressive.

Zodiacal light was visible but not a whole lot greater than from San Fran. Did seem more pointy in shape, and higher.

We used the 235mm SCT scope which really performed well under these conditions. Most descriptions are at 117.5x.

The thing that really made a difference was using an eye patch - I kept my dominant eye covered up the entire time except when actually looking in the eyepiece. Even a 21.25 sky with stars seemed bright enough to keep one's eye from getting fully dark adapted. I'd say that it was like having an extra couple inches of aperture at least. Galaxies that looked like their usual elliptical fuzzball shapes with the uncovered eye (used for reading observing plan, etc.) looked positively bright with the patched eye, and depending on the galaxy, showed off texture, large haloes and/or spiral structure, etc.

We spent most of the night checking out highlights of the Vir and CVn galaxy clusters. Here's some of what we saw:

M83 - looked good, not much to say about it though

M68 - very rich and beautiful cluster

M65 and M66 - These were bright and very distinct looking, with NGC 3628 also easily seen.

M97 - not too exciting but at least one dark spot was visible intermittently.

M104 - It looked great, dust lane readily visible and the thin part on the other side of the dust lane not hard to see

M84 and M86 - These and at least 8 other NGC galaxies in (and near) Markarian's chain were easily visible

M59 and M60 - Easily seen, as was NGC 4647 right near M60

M64 - Looked good but 'black eye' was somewhat less prominent than I expected.

NGC 4567/4568 - the 'siamese twin' galaxies were surprisingly easy to see, as was NGC 4564 nearby

NGC 4298/4302 - this is a neat pair, an edge on spiral right next to a mostly face on tightly wound spiral that looks like an elliptical. We were pleased to be able to see this contrasting pair.

M100 - Not only did we see it, but also readily saw the swirly texture of its halo hinting at spiral arms.

NGC 4449 - This galaxy seems to have a strange rectangular shape in survey images. It looked odd, but not exactly rectangular visually, with texture and knottiness.

NGC 4631 - This is the whale galaxy and also showed a 'bumpy' texture that reminded me of very coarse sandpaper. NGC 4627 was not hard to see nearby.

NGC 4565 - dark lane was very prominent, cleanly slicing the core, especially at about 140x, but couldn't see it extend as far beyond the core as is shown in survey images.

Besides these, we also saw a bunch of other items such as NGC 5005, NGC 4244, M63, NGC 4656, M98, M16, M20, M24, M18, and M9 - M9 was fantastic and really took magnification well.

With the steady seeing I was able to see 3 distinct and unusually thin bands on Jupiter at about 800x, if I remember the eyepiece in use at the time.

M101 was very impressive. Once the sky got darker later, its lopsided spiral shape was fairly apparent. M51 also showed a swirly appearance.

Near the end of the public program, the observatory-master graciously accepted my request to see the triplet of edge-on galaxies NGC 4216/4206/4222. These were all nicely visible and framed in the FPOA 30" scope. For those with large scopes, I recommend these as a nice grouping.

We totally ignored the moon and saturn.