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Observation Report
Lake Sonoma, Jan. 12, 2002

by: Robert Leyland

Sadly the weather in Marin and southern Sonoma counties was pretty messy, an awful lot of low fog following the continuous cloud cover since earlier December had wrought havoc to my carefully planned observing schedule. (in other words, I hadn't opened a starchart in over a month :-)

The weather prognosticators did indicate that lake Sonoma would be clear however, so with some trepidation off I went. Cresting the hills between Novato and Petaluma I could briefly see above the fog, and surprise-surprise no clouds. It was all low lying stuff, that was encouraging, as was the disc of the sun visible through the fog.

Lake Sonoma was remarkably clear, with many stars visible by 6:30pm, and the Milky Way clearly showing by 7pm. There was some low lying fog on the lake itself, at Grey Pine Flat (900ft) we were above it, but the fog continued to be a worry all evening, as we were fighting off dew several times.

A small group had gathered at Grey Pine Flat, with Matt and his trusty 8" on the Tuthill mount chasing IC nebulae, George Golitzen with his "new" 14" Dob happily knocking off bright Ms and NGCs all evening, and Dave Staples also working at completing the Ms in his 8". Robert (from Los Gatos?) had made the trek up with his 20" Obsession, and showed us some terrific views during the evening.

Technical data
Date/Time: 12 Jan 2002 - 1830-0130 PDT (UT -8, or 0230-0930 11 Jan 2002 UT)
Location: Lake Sonoma CA, 3843'N 12302'W Elev ~900 (Grey Pine Flat)
Weather: 7-11C Temp, 75%-98% Humidity
Instrument: 17.5" F5 Dob, Telrad + 9x50 finder scope
Oculars: Pentax XL eyepieces
Seeing: LM 6.5+, transparency 7/10, steadiness 8/10, zero wind

Early evening views of Jupiter and Saturn were encouraging; with a shadow transit in progress and a "brown barge" very prominent on the surface of Jupiter. Later the teensy moon (Io?) exited the planet, a bright anti-dimple poking out from the equatorial region. We tried Matt Marcus' H-Beta filter on the planets, which to my eyes did not do a lot, other than coloring the planets a vivid orange/red and letting me see a little more of the bands, perhaps just by reducing the brightness.

While we had the H-Beta filter in place, and prompted by recent discussions, we went for the Horsehead nebula. Starting from Zeta Orionis, I first picked up the flame nebula (NGC 2024), and looked 90 off Zeta to find the dark incursion in the nebula. Not too hard to find in the 17.5" at 110x, but impossible to see without the filter, and when I later tried to see it with a UHC filter I didn't have any success either.

Even so the sky was pretty dark, we did a visual scan for Messiers, many of them were easy, and quite bright including Andromeda galaxy, the Beehive cluster, M35 in Gemini. After a month away from observing the bright eye candy objects are hard to resist.

Remarkably, M33 was showing, visible with direct vision to several of us, and averted vision for others. In telescopes it showed tremendous structural detail, knots in the arms, with dark lanes between them.

Speaking of dark lanes, M31 (Andromeda) was also a treat tonight, double dark lanes, and very nice branching structure in the lanes, and the band between them. NGC 206 star group, just off the M32 end was pretty nice, and gives a good idea of the scale of the galaxy.

We also took peeks at NGC 2903 galaxy in Leo, as it was rising, followed by MGC 7331 galaxy in Pegasus as it was setting, clearly giddy from photon deprivation!

Getting to my list of DSOs in Cetus, I first tracked down M77, a galaxy formed from an oval glob of fuzzy stuff, with a bright core, faintly visible in the 50mm finder. Using M77 as a base, for star/galaxy hopping we're off and running.

NGC 1055 galaxy is quite close to M77, next to a pair of bright field stars by Delta CET. 1055 is a sizeable oval glow, a slight band in the core is sharply cutoff towards a little equilateral triangle of stars. Some nebulosity is visible just beyond the darker region, leading up to the brighter star of the triangle, possible the other side of a dust lane. On the other side of the galaxy (towards M77), but separate from it, is a very faint blob, at 220x it is noticeable, and averted vision brings it out. Matt was able to verify my imagination, but neither of us could really resolve any details.

Pushing past Delta CET brought up another galaxy, NGC 1032. Forming the fourth star of a quad with 3 field stars, it is elongated in line with the side of the quad, an easy direct vision object with a diffuse core.

Next up is the larger, but more diffuse galaxy NGC 1073. It shows a central elongated bar; with a large halo. At 220x, and with averted vision some very faint pin prick stellar points speckle the bar in a line along the edge.

NGC 1016 is smaller, and like 1032 is a slightly elongated oval in a quad with three field stars, however in this case the galaxy "points" to the center of the (fainter) quad. A soft core is visible at higher power.

Star hopping to NGC 864 was more of a challenge than it ought to be as I neglected to drop back to a lower power eyepiece (tiredness, and a month off, will reduce your effectiveness). At 100x it is easy to see as an oval shape adjacent to a bright field star. At 220x the diffuse core looks to be oriented at 45 to the star, and the large halo extends to include the star.

By this time (11:30pm), Cetus was well past the meridian, and the lower portions were too low for comfortable viewing.

I took a peek at NGC 2017, an asterism in Lepus, which to me resemble the Greek letter Tau. According to the diagram in NSOG two of the stars are close binaries, but I was unable to split them, even after re-checking collimation. The seeing was really up to powers much over 200x.

So late night eye candy time... A few galaxies in Leo, including NGC 3412 & 3377 amongst old friends M65/66, 95,96 et al, then NGC 1999 nebula in Orion, with its nice dark incursion very obvious at 220x; the Flame and M42 of course. Sharing views, comparing views, and many "oohs", and "ahhs".

It's great to be back out, even if it's 7C and the 90+% humidity is causing dew to form on every upturned surface, those ancient photons do need collecting.

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