Make your own free website on Tripod.com

Observation Report
Lake Sonoma, December 9, 2001

Linear and Cetus

by: Robert Leyland

With our recent spell of poor weather, seeing a clear deep blue sky on a Sunday afternoon, was encouragement enough to get me out to Lake Sonoma, even if only for a short night.

My last observing session had been at the time of the Leonids in mid November, although I had taken a few glances at the comet in binoculars from home, I was looking forward to seeing it from a dark site.


Technical data
Date/Time: 9 Dec 2001 - 1830-1030 PDT (UT -8, or 0230-0630 10 Dec 2001 UT)
Location: Lake Sonoma CA, 3843'N 12302'W Elev ~900 (Grey Pine Flat)
Weather: 5-11C Temp, 50-74% Humidity
Instrument: 17.5" F5 Dob, Telrad + 9x50 finder scope
Oculars: Pentax XL eyepieces
Seeing: LM 6+, transparency 9/10, steadiness 6/10, sometimes breezy

I arrived at about 5:45, when it was already getting dark, and started to set up. A few minutes later Steve Gottlieb arrived, and by the time we had finished unpacking, placing poles, mounting mirrors, and carefully collimating it was well and truly dark. The sky was very clear, having been cleaned by recent rain from the last storm front, but consequently it not as steady as one would like.

First up the Comet (LINEAR 2000/WM1). I had printed charts with Starry Night Pro, and having seen it on two previous nights, I had a pretty good handle on where to find it. Even so, Steve found it more quickly just scanning with binoculars. Throughout the evening we would look to see if we could make it out "naked eye" with only limited success, averted vision gave me a probable smudge in about the right place, at the best of times. This with a stellar limiting magnitude of better than 6.

The comet was an easy sight in my 50mm finder, and huge in the 17.5" Dob, right at the border between Cetus and Sculptor. A well defined head, and long tail, stretched out well beyond the view of my 21mm eyepiece (100x). A few websites/newsgroup reports have mentioned an anti-tail, perhaps this is visible photographically, but not visually as I saw no trace. The comet is fairly low now (about 25 elevation), and the southern view from Grey Pine flat is not its best.

It's a very nice comet, not as great as the "Christmas Comet" hype would have you believe, but a good binocular and telescopic sight all the same.

Periodically during the evening I would return to the Comet, to see if I could see movement, and to get another glimpse of one of the Solar systems more mysterious objects. As we understand more about comets, their mystery recedes, but their beauty never will.

Then it was on to deep sky objects, I had prepared a list about a month ago, but not had a chance to follow it since then, so with SA 2000, NSOG etc. in tow, I started with some of the easier objects in Cetus, beginning just above the comet, and working generally north and east.

It took me a while to find NGC 247, as it is very faint having a low surface brightness. The listed brightness, is much higher, which reflects the galaxies apparent size. It is quite large easily filling the 100x view. A handy star in the southern end makes focusing easy, and would make a great guide star for imaging. To the north is a small group of galaxies (according to Steve G), I thought I could see one of these, but it may have been imagination, as the others are supposed to be in a nice linear row, but no others were seen [I believe I was looking off the wrong end of the galaxy].

Backtracking south to the "Sculptor galaxy" (NGC 253) is a real treat. This is a must see, a lovely elongated galaxy with clear dust lanes. Three faint field stars bracket the core which is decidedly knotty and two brighter stars flank the galaxy.

Nearby 247 is a faintish oval galaxy NGC 175, with possible traces of filamentary arms. Two neighboring field stars, and proximity to Deneb Kaitos (B Ceti) make this easy to find, despite its faint appearance.

The temperature was dipping to around 6C and a little bit of a breeze rustled the tree tops. At least the humidity was low, so we didn't have to contend with dew, just chilly conditions.

One of the big sights in Cetus has to be NGC 246 a large planetary nebula. A really nice spherical outline, enhanced by changes in brightness across the face really pop this one into full 3-D perspective. Four brightish stars inside the nebula and a couple outside provide great contrast with the gauzy nebulosity. It is a fine sight at 100x and an OIII filter at 200x provided wonderful contrast, clearly showing the increasing brightness on the edges of the bubble. One side of the nebula did seem a touch fainter also.

Due north of 246 is a faint circular fuzzy patch (it looks a bit like a faint unresolvable globular cluster), which is NGC 255. It is about 1/4 the size of the planetary, and close enough that I could get both in the FOV at the same time (100x and right at the edges). It is a nice little oval/circular galaxy, faint but with a distinguishable core.

Also nearby 246, but this time south, is another oval/circular galaxy NGC 210. This one has a clear core and is easily seen adjacent to a medium brightness field star. I can also see a much fainter galaxy in the same FOV, an elongated oval which is NGC 178. I can just hold it with direct vision, and averted vision shows the shape clearly.

Nestled at the base of a triangle of faint stars (and nearby a medium bright star), lies NGC 309, a faint slightly elongated galaxy. While not overly bright, the best view was at 210x where some structure could be seen, possibly a second bright area inside the core region.

NGC 337 forms the point of a pentagram with 4 stars (one of which is a double). The galaxy itself has a broad diffuse core, a bit asymmetric in appearance.

Next up, are NGC 274/275 a faint and small galaxy pair. The compactness of the pair, makes it look like a fuzzy double star, with one galaxy (274) easily a magnitude brighter than the other. This was hard to find, as the chart in NSOG is hard to follow, SA 2000 was much better.

I looked in vain for NGC 357 (and nearby New1/MCG-01-03-85), with no success in either case. I plan to revisit the area, with a better understanding of the layout when conditions permit, and detail charts from SNP.

Up by 45 Ceti is a nice galaxy cluster, the easiest being NGC 596 which is quite close to another bright star. It was easy to position the FOV to avoid contrast problems however and 596 is very nice. Many galaxies are scattered though this region, and crossing over the bright field star from 596, are NGC 600 and 615, which form a triangle with 596 about the star. NGC 615 is the brighter galaxy, and the star is a bit closer to 596. Pushing away from 596 leads to a V shaped galaxy pair of NGC 584 and 586. 584 is much the brighter, and both are clearly elongated, in approximately a 2:1 ratio.

Going back the other way, a hop step beyond 615 is NGC 636 which is a nice circular galaxy with a bright core, easily seen.

This is a nice grouping of galaxies, well worth revisiting on a better night.

Next to "Baten Kaitos" (55 Ceti), sandwiched between the really bright, and the moderately bright pair of stars (best to get both out of the FOV), is NGC 681 a nice little circular galaxy with a bright core, and adjacent to a little diamond asterism no bigger than the galaxy itself.

Further afield, and on the other side of 55 Ceti, is a very nice elongated galaxy (NGC 701), which makes a nice "stripe" shape, almost like a paint smudge. NSOG mentions a dark streak in the core, which I could not see, but the adjacent galaxy IC 1738 was viewable with averted vision, as a nice circular brighter patch comparable to the halo of 701.

It's now 10:30pm, and getting colder (5C/74%Hum), and getting breezier. Definitely time to go. All in all a good night, 4 hours observing on about 20 objects, just a little chilly!

NSOG - Night Sky Observer Guide, Kepple & Sanner SA2000 - Sky Atlas 2000, Tirion SNP - Starry Night Pro, Siennasoft/Space.COM [corrections added]

Back To Menu