Log, Jan 11, 2002

15 people. Les had expected this would be a pro forma "rainout" memo when Les drove over to FDO at 6PM. However by 6:25 when Les met Doug at the Dome, the sky was cloudless. The air was still quite moist but the viewing was at least 5 on our 0-10 scale, and 6 to 7 overhead. Doug made the fortunate suggestion that we open the upper two thirds of the dome because viewing was so much better than at the horizon. Temperatures hovered near freezing all night. The lack of pronounced cooling resulted in wonderful air stability later. Additionally we expected that the visitors would want to see Saturn which was almost overhead.

Outside a mother and son had set up a Christmas telescope and were very happy to have "targets" pointed out. A friend dropped by to leave us some fine photos taken at the Leonid shower. We'll post them when we get a chance to scan in her pictures. One of her photos is really magnificent. Do you remember the trail which lasted over 9 minutes? Another meteor streaked over the first as she was photographing the long lasting trail. Spectacular.

Our first target was Jupiter. We intended to keep track of the big planet throughout the night beacuse a double occulatation of Ganymede and Io were scheduled. A father and son wanted to see planets. The son wanted to see Pluto but when told that Pluto was below the horizon, he settled for Jupiter, Saturn and Vesta. Rather than trying to keep all the Saturn and Jupiter observations in chronological order, I'll group them here.

Jupiter was spectacular earlier and as the sky improved from the 6/7 range overhead to 8 or better overhead (and 6/7 at the horizons), the detail became incredible. Initially all four Galilean Moons were visible. Each presented a very clearly discernable disk with no sign of instability. As we watched, we could see Ganymede and a short while later Io slide behind the edge of Jupiter. At first contact, Ganymede presented a "pool of darkness" which surrounded it as it passed under the edge. [We did not see this effect with Io.] This effect has been captured on film in transits of Venus, but I've never heard of the effect with Jupiter and its moons! We could see the small disk slide in very distint stages until just the tiniest sliver of Ganymede was left. Shortly thereafter there was an instant replay using Io. Aboard Jupiter the detail was stupifying. 17 bands and belts of shading could be counted across the planets face. We tried various filters but overpoweringly bright as the planet was [think looking at a full Moon], it was better to view the planet in natural light. The blue filter was useless. The green #58 was better but not great. The polarizing filter allowed some bands to change relative darkness but the overall effect was a loss of acuity. The festoons on the great belts had lesser festoons. Late in the evening, Barry, still relatively new to astronomy, said it was the best he had ever seen Jupiter. Les, Art and Doug with many decades more viewing than Barry were more than inclined to put it among the handful of best sightings.

Saturn and seven of its moons were clearly visible too. Details on the planet were distinct. The crepe belt could be seen both shading the planet and as it traveled over the edge into the voids at each end of the ring. Cassini's division was clear. Encke's division WAS NOT visible. IF (and only if) it had been, we would probably have revised our estimate of the sky from better than 8 all the way up to nearly 10. As with Jupiter, we returned to Saturn throughout the evening.

Vesta was easy to find and very bright for a minor planet. It seemed to show a hint of a disk. Since we only looked at Vesta early, the "disk" may have been turbulance as the air quieted down to the later exceptional stability.

M42 was its usual overwhelmingly spectacular self. If you've seen it on a wonderful night you know what we mean. If not, get to FDO when it is a great stable clear night.

We observed several notable multiple stars throughout the night. The first of these stars was the spectacular sigma Orionis - a 6 star multiple. Four of the stars were easily visible and clearly separated. A fifth may or may not have been glimpsed. The sixth star hugs the central star to rightly to be split. The next star was omicron Eridani which many of us know as 40 Eridani. This star is 40th nearest star, about 15.7 light years away. It has three components, a yellow K 4.4 magnitude star, a white dwarf at 9.5 magnitude and a red dwarf at 11.1 magnitude. All are widely seperated. The final star we have diagramed is TY148-2162-1. This was viewed much later in the evening when we began our obscure open clsuter marathon [more to be said later]. We also cleanly split Rigel.

By this late in the evening most of our younger visitors had left and we began the more ideosyncratic part of our sky viewing. Ernie Evans had become disheartened by a period of clouds which seemed to be ready to destoy the remainder of the night. He packed up his scope and decided to move into the Dome with us. Good move! Soon the clouds disappeared and that is when the sky reached its peak.

We looked at NGC1535. This is a small, almost robin's egg blue cluster. M77 wasn't too exciting, but it was nearby so we looked at it. We knocked off NGC1400, NGC1407 and NGC1055. These are galaxies in Eridani which is south and west of Rigel (Orion's right knee). Then we went over to NGC1817 and NGC1807, two closely aligned clusters in Taurus. The next object was NGC2261 [Hubble's Variable Nebula] which looks like a tiny comet. A variable star increases and decreases the difuuse nebula's brightness. It is located in Monoceros not far from the more famous Cone Nebula NGC2262 (also called the Christmas Tree Cluster]. We viewed two nice clusters IC2157 and NGC2158. They are located near M35 [NGC2168] in Gemini above Orion's Club.

As often happens, viewing more spectacular groupings of stars and nebulae triggers a spirit in which lesser groups and dimmer clouds become the targets. Worse yet we were in an area where the Milky Way predominates. It was often hard to determine if we were looking at a true loose cluster, a portion of the Milky Way, some stars that just happened to be where the telescope pointed or nothing much at all. We can truthfully say that some of these objects were about as sensational to view as M40. [Insider's joke which Les will explain if you don't know what we are talking about].

The parade of justly obscure objects began with Basel-11B. This is a small cluster in a rich MWG background. We moved to the nearby and even less spectacular CR-89. Somehow we got side tracked from our search for the rarely seen by looking at the 40 star cluster NGC2129 and the bright star zeta Orionis. Obscurity resumed with the seldom visted HD42871, a 7th magnitude double widely separated. M78 was next and with the exception of M40, M78 is one of the least interesting Messier objects. We awarded NGC2112 the faintly coveted SMUDGE of the WEEK Award. It rated a solid "uuuunh". NGC2301 was rather nice with a bright blue star in its center. NGC2286 was hard to separate from the MWG. NGC2324 was nice also if quite faint.

By now we swung into high obscurity mode and began a Madcap Marathon of oddly named obscure objects. There are 15 Bochum open clusters. Many of then are in Puppis and were not visible, particularly with the lower shutter segment down, but we visted Bochum-2 and Bochum-3. Bochum-3 is a line of stars. Bochum-2 is truly nondiscript. Les spotted another series - the Biurkan clusters. Biurkan-10 looks like the left half of the Eiffle Tower on a bad day. Other Biurkan objects abound. What a joy when we have nothing better to do!! However Doug found the most unpronouncable category of stars of the night the Dolidze clusters. Dolidze-10 has little to offer, and what it did offer, it offered grudingly. Barry and Les couldn't spot much except a dark area between parts of the MWG. Doug thought he saw faint stars in the background. On a scale of 0 to 10, Les rates this jewel at something in the single negative digits.

We finished with some fine objects. We went to the spectacular open cluster M50 [NGC2323]. Nearby is the smaller but nice NGC2303. We finished with an appropriate old friend - the Eskimo [NGC2392]. With averted vision we could just see our old friens looking at us out of his warm parka.

We left rather early primarily because dumb ole Les neglected to take his own good advice. Without thermal LJs, his legs were chilled to the bone. It wasn't 1AM when we left, but it had been a full night.

-Les Coleman

Leslie Coleman
Leslie Coleman
Entry Date:
Jan 11, 2002
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Leslie Coleman's Log
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