Kinks seem to be worked out

User avatar
Astro Day Coordinator
Posts: 3714
Joined: Fri Jun 13, 2003 9:03 pm

Kinks seem to be worked out

Unread post by Pete »

25 Nov 2013

Still fighting the last of a bug, but contrary to forecasts the sky was clear toward dusk so I started running some dark frames while working out a problem downloading the latest MPC critical object list. Both computers were choking so perhaps it was at the Harvard end?

Air temp’s 27°F and the wind’s calm. Sky appears to be transparent.

Quick visual of Venus thru the guide scope at 30X. It’s about 34% illuminated and about 35 arc-seconds in size as it approaches opposition. And it's also in the trees.

141079 is a 2 km sized Apollo now .6 AU distant and 18.7 magnitude. Obviously the asteroid has undergone orbital permutation as the uncertainty level is 3 out of 9 and the RMS residual is 0.63 Motion is 2.257’/hr and I overlooked that when I set 3 minute exposures. Imaged from 18:26 – 18:57 hrs at 3 min, 2X2 binning, -30C cooling, 20 Hz guiding. What I consider an overly long exposure that will cause a 7 arc-second streak didn’t seem to be a problem with S/N ranging from 7.4 to 9.4 and FWHM from 4.4 to 3.4 (relatively tight). So the clouds aren’t here yet and the seeing’s pretty good. Frames 1, 4 & 7 show dRA & dDEC = 0.0’

Asked Dave to snap a picture of the Old Man sitting out in the cold when he could be running Windows Remote from the warmth of the house:
This might be a bit strange, but I like to be outside ‘cuz that’s where the stars are.

2010 CL19 is another 2 km sized Apollo. It’s relatively close at 0.1 AU, relatively bright at 15.7 magnitude, and relative motion is a really fast 20’/hour. Uncertainty level is 3. Imaged from 19:05 – 19:14 at 15 seconds, 2X2, -30C, 1 Hz. Don’t have a reduction set up for it so used auto-darks. Frames 1, 4 & 9 show dRA = +0.1’ and dDEC = 0.0’ S/N ranged from 10.0 to 14.8 and FWHM ranged from 3.7 to 4.7 (Nice tight images).

Whoops! There’s the forecast cloud. Thick and horizon to horizon. In at 19:30 hrs. 6 observations transmitted to the MPC by 19:45.

Conclusions & lessons learned:

The dew/light shield seemed to work well as there were no noticeable reflections from the red light illuminated dome interior getting through to the chip.

Usually at least 1/3 of my observations show deviation. After 27 consecutive observations 2010 CL19 is the first detection of a noticeable deviation between my astrometry from the predicted ephemeris. It’s kind of a relief to see it happen.

The kinks seem to be worked out :P

hgp logged 20:16 hrs., 25 Nov 2013
Pete P.