Pete's observing log of 15 Dec 04

[Pete]

Observing Log of 15 Dec 04

Looks like it will be the second clear night in a row tonight. The 12” was set out on the pier to cool down at 17:00.

18:30 Lou showed up with his scope and began to set up. I joined him after about 15 minutes. Ran a 2 star precision polar alignment using Denab and Capella. Slewing to Aldebaran, the scope was way off. I centered and synched on Aldebaran and the scope was dead on for the rest of the night. Temperature was 23°F but there was no breeze, the moon had set, it was cloudless and seeing and transparency were excellent.

15 Dec 04; 20:11 hrs. Asteroid 336 Lacadiera is a dim 13.1 magnitude minor planet 1.5 AU from Earth and 2.5 AU from the sun. Lacadiera is approximately 72 km in diameter. The go-to was right on after synchronizing the scope on Aldebaran, but I had to switch from the Nagler 31 to a 20mm Plossl (150X) to view this object thru the 12”. Fortunately Lacadiera occupied a vacant piece of the sky so that there were no nearby stars to confuse the ID.

15 Dec 04; 20:24 hrs. 65 Cybele is a 12.3 mag asteroid in a distinctive star pattern – an easy find in the 12” at 98X. Cybele is large – 245 km in diameter. 2.8 AU from Earth. 3.8 AU from the sun.

20:56 hrs. Asteroid 378 Holmia is a dim dim 13.4 magnitude in a distinctive star pattern. I kept increasing magnification and the nearby 12th mag locater stars became quite easy to see when I finally reached 256X thru the 12” using a 12.4 mm Plossl. Using averted vision, high mag, and scope movement I think that I saw Holmia blink in for an instant once or twice during my search. The object that I may have seen was right where the plot shows Holmia should be. But this one is very very iffy. I won’t claim it tonight.

21:05 hrs. I’d viewed Comet C/2004 Q2 Machholz last night thru the scope. Tonight it was masked from our scopes by a tree, but I did a go-to on the 12” just to figure out where it was. And then I moved over 15’ and viewed in the direction the scope was pointing thru my Oberwerk 15 X 70 binocs. Experience has shown that large comets are best viewed thru binoculars. Machholz is very big and bright at mag 5.2. It’s about 35 seconds in diameter. Although no tail was visible thru the scope, there appears to be a wide very short tail extending through 180° and centered on north. Lou took a look thru the binocs and then put his scope on it.

21:10 hrs. Showed Lou M42 (the Orion Nebula) thru the Oberwerks. There’s a lot of contrast when seen in the binoculars. Then I dropped the Orion Ultrablock narrow band filter onto the Nagler 31mm in the 12” and blew Lou’s socks off viewing the Orion Nebula thru a full 1° fov.

21:48 After about ½ hour of observing I was unable to nail down asteroid 517 Edith. Edith is a reasonable 12.7 magnitude, but it’s not exactly where it’s supposed to be, and replotting it for the current minute with Guide 8 doesn’t solve the problem. It’s one of 2 “stars” that are close together, and one of them is Edith, but I can’t tell which is which.

15 Dec 04; 22:09 hrs. Asteroid 192 Nausikaa is a brilliant 9.8 magnitude in a field with 6th mag & 7th mag finder stars. It was a relatively easy find star hopping in from the east. Viewed at 98X thru the 12”. 107 km diameter, Nausikaa is 1.2 AU from Earth and 2.1 AU from the sun.

15 Dec 04; 22:15 hrs 50 Virginia is a bright 11.7 mag asteroid 93 km in diameter, 1.2 AU from Earth and 2.2 AU from the sun. Virginia must be a real speed demon as it’s out of position by several minutes, and the chart isn’t more than an hour old. I subsequently confirmed its movement by replotting it for 22:15 hrs. Viewed thru the 12” at 98X

22:15 hrs. Lou is starting to pack up, and since I was out late last night I turned on the yard lights and started packing away myself.

Comments, conclusions & lessons learned:

It was cold. We ducked into the house half a dozen times to warm up.

2 nights in a row of observing after a month of cruddy weather. Yeah Hooray! And it’s always twice as much fun when you have company to observe with. Thanks for dropping by Lou.

Pete