Pete's 19 Jan 06 observing log

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Pete's 19 Jan 06 observing log

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Observing log of 19 Jan 06

While lighting off the barbecue grill around 17:00 I noticed the clouds breaking up a bit. Checking the computer, while the clear sky clock suggested overcast all night the IR satellite suggests that the sky will clear around 20:00. I’m really anxious to view one of the last 3 low numbered (below 100) asteroids that I haven’t logged yet, and with our unstable New England weather this might be my last chance at it this year. Asteroid 99 Dike is a very faint 14.4 magnitude, so I got Dave to help me haul the 14” out for cool down.

19:30 hrs. It’s still about 60% cloud cover, but I let the scope run an automatic alignment on Capella and Saiph. Saiph is a new star to me. It’s the bottom left star in Orion (Rigel being the bottom right star). Since tonight is “iffy” I don’t spend the time to run a precision alignment with a reticuled eyepiece. Once done with the alignment, I glance to the W and note that the horizon seems to be clear of cloud and the clearing is indeed approaching.

19 Jan 06; 20:25 hrs. Asteroid 99 Dike was 14.0 magnitude during closest approach in December, but it’s now a dim 14.4 magnitude according to Guide 8. 14.4 is really reaching deep for me, and the reason that I took the trouble to set up the 14”. As I’m star hopping in from a 5th mag star to the N I notice that the sky has cleared beautifully. And fortunately Dike is nearly at the zenith tonight. Dike and a nearby 14.3 magnitude star are conveniently bracketed by two 11th mag stars that are 4’ apart. After centering the location where Dike should be I start increasing magnification from 115X to 209X, 296X and finally 395X – where I can readily view both Dike and the nearby 14.3 mag star using averted vision. Dike is 86 km in dia. Its heliocentric radius is 3.1 AU, and it’s presently 2.3 AU from Earth.

Just as I’m finishing up logging Dike, Jim Braga pulls up. He takes a look for Dike, but his driving vision isn’t dark adapted yet and can’t make it out.

I slew the scope to M31 at Jim’s suggestion, and he views Andromeda as I duck into the house to generate the next asteroid chart. Andromeda’s core is quite bright tonight, but I can only see about 30’ size before it disappears.

M42 is the next stop, again at Jim’s suggestion. He views thru the Nagler 31, and then thru the Nagler with Orion’s UltraBlock filter. Although I have other filters, the Ultrablock really makes the Orion Nebula stand out high-contrast and bright through a field of at least 1° in size.

We then took a shot at the Flame nebula and the Horse Head nebula. Couldn’t see a trace of nebulosity in either regardless of which filter we used (including the H-beta). Hmmm…. I guess the sky isn’t as dark and contrasty as I thought it was.

19 Jan 06; 21:29 hrs. 323 Brucia is shining at 12.2 mag tonight. Brucia is just a few arc-minutes above a 10th mag double star, but Brucia is a fast-mover and it’s not where I’d plotted it earlier. To add to the confusion, the asteroid seems to be closer to 13.0 mag, and there are two faint 14th mag stars above and below Brucia that aren’t plotted. Using the 14” at 209X, and aided by an up-to-the-minute enlarged plot, Jim and I finally confirm viewing Brucia. (The following day I pulled up the Deep Sky Survey and overlaid it on top of our plot. Those two 14th mag stars did show exactly where I marked them on our working chart.) Brucia is approximately 38 km in size. It orbits Sol at 2.1 AU and is presently 1.1 AU from Earth.

We next attempted to view 13.5 magnitude asteroid 390 Alma. But even at 209X we’re no longer seeing to 13th magnitude. We’re clouded out for the moment.

Saturn is now high in the East, so we slew to Saturn and view thru the Nagler 17mm (209X). The sky is quite stable now. We can see the Cassini division and the Crepe ring, as well as faint equatorial banding on the planet’s surface. Titan, Dione, Rhea, Tethys and Japetus are visible. But we were unable to observe 12.7 magnitude Mimas (which lies close in to the planet) or 11.5 mag Enceladus (also close tonight) us even when using a 9mm occulting eyepiece. And we were unable to view 14.0 mag Hyperion regardless of magnification used. Actually at 531X I may have viewed Hyperion but it was such an ephemeral thing that I can’t actually claim it.

22:45 hrs. Tonight Saturn lies just 1° below M44 (the Beehive). So we slewed to M44 and were dazzled by the large bright cluster. Those stars are really bright in a 14”.

I’m badly chilled at this point. The temperature’s only 36°F, but I’m not properly dressed. I suggested to Jim that we duck inside to warm up. Apparently it’s late for him, and he heads for home.

19 Jan 06; 23:31 hrs. Asteroid 535 Montague is a relatively bright 12.9 magnitude. Star hopping in from a configuration of four 10th mag stars to the E, Montague lies just 4’ N of an 11th mag star. I’ve got the 11th mag star in the Nagler 31, but don’t see the asteroid. Even using the 17mm eyepiece (209X with the 14”) I don’t see Montague. Something’s very wrong here. Cartoonist’s light bulb goes off over muddled head, and I lower the scope to find the corrector plate heavily dewed up. Once I apply the hairdryer to the corrector plate I’m viewing Montague as well as 13.2 and 13.7 stars 2’ and 3’ N of Montague respectively. Montague is 77 km in dia. It orbits Sol at 2.5 AU, and it is presently 1.55 AU from Earth.

The sky appears to be hazing over a bit. The rising moon illuminates a large zone of haze around it, and although the stars overhead appear to be bright, and factoring in the dimness of the 13.2 and 13.7 stars near Montague, I have to assume that the whole sky is gradually hazing over.

19 Jan 06; 23:42 hrs. 278 Paulina is presently shining at 13.0 magnitude. Using the 14”, I’ve got it with the Nagler 31 (115X) by star-hopping down a string of 10th mag stars to the N. I’m not seeing 13.5 and 13.7 mag stars that are nearby (but because of their plotted location couldn’t be confused with Paulina). Guess the increasing high haze and the rising moon’s impact on contrast are being felt. Paulina is a 38km sized minor planet orbiting the sun at 2.6 AU. It now lies 1.7 AU from Earth.

Although I’ve other asteroids plotted, the sky is becoming unworkable with the moon and the haze. Since it’s late, and tomorrow’s a workday, I prepare the scope for “sleep” mode – as I’d like to attempt daytime planet observations tomorrow. Only in my tired mind I forget to set the sleep mode, and then pull the wrong plug – crashing the scope computer’s memory. So I pull the Mylar cover over the scope and tripod and bring everything else in for the night. Things are scattered all over the kitchen, but I’m in by Midnight.

Conclusions & observations:

I really should have ducked in and grabbed a warmer coat before getting chilled. I’m coming down with something on the 20th as I write this up.

It’s really strange that the sky was clear enough to permit observing a 14.4 mag asteroid but not clear enough to view the Flame or the Horse Head. Guess that just underscores how difficult it is to view these nebula.

I only logged 4 asteroids tonight, but getting 99 Dike was worth tonight’s effort all by itself.

Today’s forecast shows clouds rolling in later this afternoon. So I’ll get Dave to help me put the 14” back up in the office.

Last summer Jim built a roll-off roof observatory for his equatorial pier mounted 8” Newtonian. I can’t recall hearing about this before. Yikes! Seems like everybody’s got an observatory but me.

Thanks for keeping my company Jim. Hope you enjoyed it as much as I did.

Pete 20 Jan 06