Comet Machholz & the asteroids - observing log of 14 Dec

[Pete]

Observing Log of 14 Dec 04

Looks like it will be a clear night – at least for a couple of hours. So I put the 12” out to cool down at 17:00.

19:00 Ran a 2 star precision polar alignment using Denab and Capella.

19:15 Started search for asteroid 71 Niobe, and found that my chart was defective – there were no stars brighter than 12.5 magnitude printed on the chart. After playing with the software for a while I figured out that my computer had suffered some disk corruption last week and it apparently affected Guide 8. I had to reload both CDs – a process that took more than an hour. Novice astronomers might wonder why we make such a fuss about equipment…. When something goes south on you you’re out of business.

14 Dec 04; 20:12 hrs. Asteroid 71 Niobe is a bright 12.1 mag minor planet only 2.7’ E of Mirphak. An easy find even though Guide refused to print out stars of more than 12.5 mag. 2.3 AU from Earth and 3.2 AU from the sun, Niobe was viewed thru the 12” at 98X.

14 Dec 04; 21:26 hrs. 796 Sarita is 12.0 mag asteroid 1.3 AU from Earth and 2.2 AU from the sun. Sarita is in a tough field and took a while to identify using the 12” at 98X.

14 Dec 04; 22:00 hrs. Comet C/2004 Q2 Machholz is very big and bright at mag 5.2. It’s about 35 seconds in diameter, but has no tail visible in the scope. Binocs would probably be better for viewing the tail, but it’s too cold to get too involved just now.

14 Dec 04; 22:15 hrs. Asteroid 62 Erato is a bright 12.3 magnitude in a difficult field lacking outstanding locater stars.. Erato is a 93 km dia. asteroid 1.7 AU from Earth. Viewed thru the 12” at 98X.

14 Dec 04; 22:21 hrs. 106 Dione is an 11.2 mag asteroid 1.7 Au from Earth. It’s in a field with bright finder stars, and a relatively easy find. Viewed thru the 12” at 98X.

14 Dec 04; 22:30 hrs. Asteroid 283 Emma is a 12.9 mag object in a rather bland field of stars. Took a bit of looking in the 12” at 98X to find it. 1.9 AU from Earth.

14 Dec 04; 22:59 hrs 683 Lanzia is a 13.2 mag asteroid that I located by star hopping from an 8 mag star abut 30’ to the SW. Viewed thru the 12” at 98X. 116 km dia. Lanzia is 2.4 AU from Earth and 3.2 AU from the sun.

14 Dec 04; 23:08 hrs. 952 Caia is a 12.8 mag asteroid 1.5 AU from Earth and 2.4 AU from the sun. Caia was easy to locate in the 12” as it was directly in the middle of two 8th mag stars, but I had to increase magnification from 98X to 117X (26mm Plossl) to break Caia out from a bunch of very nearby13th mag stars.

14 Dec 04; 23:14 hrs. Asteroid 80 Sappho shines at a bright 10.6 mag and is near a bright locater star – an easy find in the 12” at 98X. 82km diameter Sappho is 1.1 AU from Earth and 2.1 AU from the sun.

23:21 hrs. Comet P/Gehrels (78P) is 12.1 magnitude. I’m right on the star pattern printed out by Guide but the comet is invisible.

23:26 hrs. Comet C/2001 Q4 NEAT is supposed to be 11th mag. Can’t locate it.

23:30 hrs. Comet C/2003 T4 LINEAR looked like it was up on the chart, but I must have wandered off of the zone as the scope computer informs me it doesn’t rise for another hour.

23: 33 hrs. It’s down to 21°F now and I’m freezing my buns off. Time to quit. But first a quick look at Saturn at 98X. Can see banding even at this low power. The sky has steadied some.

Conclusions & lessons learned:

Didn’t realize just how dependent upon Guide 8 I’ve become. You just must have it for asteroid hunting. No other software will do.

Comet Machholz is a fine sight and may grow to naked eye visible.

After a month of bad weather we got a break. I viewed 8 asteroids tonight, along with a very nice comet.

Pete