Walter's LogBook
	December 2006

Overview

Only one night of CCD imaging was done this month due to a failure in the heatsink retention mechanism of the observatory computer. The weather was so cloudy this month that only two nights of CCD were missed, and visual observations used up the rest. The highlight of this month was definitely a very pleasant Christmas Eve all-night visual session in the dome!

With the P4 out of commission (from Dec 15 onwards), I was forced to do my supernova searching on the PII (400MHz) machine (a slower more time-consuming process!). In one field I noticed a star with noticeable proper motion -- see the notes below.

The SXV-H9 is the imaging camera, with exposures for variable stars of 120 seconds at 4x4 binning (unguided). This month's session notes are below the overview section.

Monthly Statistics, December 2006
Night	Imaging Time (s)	Exposure Time (s)	# Targets	# Exposures	T (C)	/\T
12/07/06	37989	32760	66	273	-3.3	-6.8
1 nights	37989 (10.55 hr)	32760 (9.10 hr)	66	273

Session Notes

2006 December 7/8

The CCD was run for about 10½ hours. Deteriorating conditions at dawn stopped the session.

2006 December 21/22

I did visual variable star observing in the dome tonight from 18:00 until 22:55.

2006 December 24/25

This was the most pleasant and memorable session I've had in years! It was a nice, quiet Christmas Eve with a clear sky, though with only average transparency at best. Given the warm temperature for this time of year (-2C!) it was an acceptable trade-off! This was a visual session in the dome! I observed from 20:00 until midnight, then had a nice nap in the reclining chair in the living room with the radio on. Then I observed from 02:00 until dawn. I visited variable stars almost exclusively tonight, since the transparency didn't justify spending much time on deep sky observing. I did look at Saturn though, since it is nicely placed near Regulus.

2006 December 29

While inspecting a field for supernovae, I noticed one of the stars in the field was moving! (None of the other field stars exhibited any noticeable motion.) From the FITS headers I discovered that there was 17 years between the "old" and "new" images! PinPoint gives the star's positions as follows:

1989-12-06 07:01:10.99 +51:18:50.3 (2000)
2006-12-29 07:01:12.02 +51:17:47.4 (2000)

so the star has moved about 2s in RA and 3" in dec. The USNO A2 catalogue gives Mr = 15.1 and Mb = 15.3.

I have noticed stars moving relative to their fields on half a dozen occasions during supernova searches this year. I like these little extra incidental "surprises" along the way.

A Moving Star

The star is moving towards the bottom.