Once again I headed out to Lake Sonoma for that extra couple of magnitude over my back yard, it is also hazy and cruddy over cast as I drive north. Venus, and the crescent moon can be seen through the murk surrounded by a cloudy glow. Traffic is a busy, and adds an extra half hour to my trip, but it was worse for Jim Shields who made the trip a little earlier, and it took him 2-1/2 hours from San Francisco. It has not been this bad before, mostly because I have come up on Saturdays.
Steve Gottlieb also made the journey, arriving a little after I did. We set up our scopes at Grey Pine flat with good views everywhere, except for some cloud to the west. The first couple of hours were a bit iffy, as the cloud/fog moved in and out of our views. We were almost completely clouded out between 8 and 9, except for "sucker" holes near Orion. However, that cloud rolled over by 9pm, taking all the crud with it, and the sky was crystal clear for the rest of the night. The temperature was a pleasant 5-10°C (40ish F) and the humidity never got over 81%.
Steve and Jim have larger telescopes, and are seeking out peculiar galaxies, and planetary nebulae. During the evening they were quite willing to share their views of some really odd looking galaxies in collision, or super clusters of stars within galaxies. I am developing a severe case of aperture fever :-)
| Observer | Robert Leyland |
|---|---|
| Date | 28-29 Dec 2000 |
| Time | 1900 PST - 0130 PST |
| Location | Lake Sonoma CA. 38°43'N 123°02'W Elev ~1500 |
| Weather | 9°C Temp 71% Humidity |
| Seeing | LM 6.5, passing thin layer of high fog early, cleared completely by 2100 |
| Equipment | 8" F6 Dob, Pentax XL EPs |
While Andromeda is still high in the sky I look for NGC 7662 (Blue Snowball) and NGC 7640, to follow up from the previous observations. The wisps of high fog don't help, but there are some good clear times. NGC 7662 is better than before as the adjacent star is visible with direct vision in the 21mm EP (55x), and the Blue Snowball lives up to its name, with lovely deep pastel blue coloration, hints of spherical structure, and faint tendrils of mist particularly nice in the 7mm (115x). NGC 7640 still avoids showing me any nebulosity, but the central core area does show some elongation.
In Steve Gottlieb's 17.5" the nebulosity show nicely, but it is dim which explains why it isn't visible at all in the 8". Steve explained that, he finds, for viewing galaxies a 2mm exit pupil gives the best result, as that enables you to concentrate the light onto the most sensitive regions in your eye. He uses a 20mm EP for finding and an 8.8mm (220x) for studying which gives him that desired 2mm exit pupil on his f4.4 Dob.
By 9:30 I had moved on to Triangulum, which was now favourably positioned above Andromeda.
NGC 890 shows faint nebulosity surrounding a bright central core. I can tell it is not just scattered light by comparing with adjacent stars of similar brightness. At 85x the nebulosity resolves better but is still faint.
NGC 925 is a very nice galaxy with a line of stars along one side, and a brighter star off the edge. The misty nebulosity is more prominent than 890 and the central core it notably elongated, while not as bright at the peak it is easier to see, as it is more spread out.
Epsilon Tri splits at 170x, into two stars, with the second star being much much fainter than the primary. It is closer than gamma And, and quite similar in separation to iota Tri, as stated in NSOG. The brightness difference makes it much harder to separate, showing that this night has better seeing than two days earlier.
Looking like a faint "blade the galaxy NGC 784 shows up well at 55x, it is surrounded by a trapezoid of bright stars right at the edge of the FOV of the 21mm EP, with a group of faint stars surrounding it closer in. Using the 10.5mm these faint stars fill the view, leaving the galaxy in the center. The best view was at 85x, with averted vision the galaxy's shape was quite clear, although it is faint.
Steve Gottlieb shows me a couple if sights I'd not seen before, one was NGC 1999 in Orion, which is an emission/reflection nebula with a dust cloud "incursion". The dust is very dark, forming a little sideways V-shape around the central star. The nebula can easily be seen in my 8", and later I have a look at it. The darkening is noticeable as an asymmetry in the center of the nebula, and I am sure I would have overlooked it without first seeing it in Steve's scope.
Jim Shields has M82 at high power, in which he is looking for super-clusters, earlier he had a colliding pair of galaxies in view. A small oval galaxy running into the middle of an edge on. The pair looked like a high wing airplane, or the Enterprise (Star Trek) viewed from the front. Quite a treat. Jim suggests looking at "Thor's Helmet", after a few minutes Steve has it in view, and that is quite a sight. The helmet looks like its namesake, with a high eye-guard, and a neck flap in place, and a darkened area where Thor's face would be, and fainter mistiness past the face accentuates the region.
Back in Triangulum NGC 949 shows as a faint mildly oval fuzziness, averted vision shows a brighter point in the "lower" middle. Is is quite a cool shape, and relatively easy to find using NSOG (V1-p396)
Collinder 21 is a cute little "ear" shaped open cluster that I come across almost by accident. I wasn't really looking for it, but the image jumps out at 55x, listening to me, as I track down NGC 672.
This looks like a little "flying saucer". There are two very faint stars on either side of the galaxy that need averted vision to see, the star on the same side as the triangle asterism is just a tad brighter. Both NGC 672 and Cr21 are viewable in the same FOV at 55x.
It is now a little after midnight, and before packing up, we take the time to visit some bright old friends.
A peek at the trapezium shows the fifth star easily, and in Steve's 'scope the 6th and 7th as well. The nebulosity around the trapezium looks bubbly in the big scope, showing a lot of fine structure.
I look for the Horsehead nebula, NGC 2024 looks very good and moving off Zeta Ori I can see a faint edge which must be IC 434. I think I can see the Horsehead, but it is probably wishful thinking, as NGC 2023 which is nearby doesn't show much nebulosity. Steve has an H-Beta filter, and we get an excellent view of the Horsehead against the emission nebula. In a curious coincidence the Horsehead is the astronomy picture of the day on Friday. My 17 year old son thinks it looks more like the back end of the horse, but even he is impressed by the picture.
Jupiter and Saturn are well situated, now high in the sky, for viewing. Jupiter looks amazing, one of the best views I've had. Four moons are visible, but one is much fainter, and surely can't be one of the "Gallilean" moons, I'll have to check with Starry Night Pro later. The equatorial bands are clear with one split into two bands, with a lighter center. Swirls and festoons between the bands, and a number of bands away from the equator are quite obvious. [Sure enough the fourth "moon" is a 9th mag star, HIP18787 in Taurus, Io is hidden behind the planet we'd have need to wait until 3:05 AM to see it appear]
Saturn is wonderful, four of its moons form a perfect parallelogram, with Saturn offset to one edge. A fifth moon is visible close to the center of the parallelogram. The Casssini division is visible all the way around the ring, and subtle bands show on the planet itself. [The moons forming the parallelogram are Titan, Rhea, Dione, and Iapetus, the fifth moon was Tethys]
What a great night. Clear skies, especially after 9pm, and steady air, no wind, good humidity. I would have stayed later, but tiredness was setting in, and I still had to drive home.