Comet Lovejoy trials and tribulations

Friends have asked if I got pictures of the comet (Lovejoy C/2014 Q2) and I’ve been reluctant to admit, that, yes, I have, but that they are pretty bad pictures.

The first was a wide field shot in which I imagined seeing the comet’s tail streaming gracefully among the Hyades and the Pleiades. For tracking, I mounted the Canon 60Da piggy back on the Takahashi, set the camera’s intervalometer to take 60 1 minutes shots, and went in the house. About 10 minutes later, I let the dog out, and the sky had socked in, and was spitting snow!. So I shut things down, having got 5 minutes of usable exposure in. There’s the merest hint of a tail, if you look close, and really want to see it. I shot the images at 28mm, f/5.6. The comet is really small in the frame, although it would have worked ok if I could get more exposure. Actually I think the picture captures the impression you get with binoculars.

Comet Lovejoy Jan 14, 2015.  Canon 60Da; 28mm @ 5.6; 5 x 60 seconds.

Comet Lovejoy Jan 14, 2015. Canon 60Da; 28mm @ 5.6; 5 x 60 seconds. Click for larger image.

 

The next clear night I used the STL 11000, and was able to see really nice detail in the comet’s tail. Unfortunately, the camera was overdue for the annual regeneration of its dessicant plug, and the image is overlain by the shadows of tiny ice crystals. So I took a few pictures and set up for flat fields, hoping I could zero out the frost. The frost is a moving target, and the flats weren’t helpful. So the image below is 5 minutes, dark-subtracted and auto-background-extracted in Pixinsight. The black cuneiform is what frost looks like on a chip. You fix that by removing the desiccant plug from the camera, and popping it in the oven for 4 hours at 350 degrees, which I did the next day.

Comet Lovejoy Jan 15, 2015.  STL11000 on Tak FSQ 106. 5 min exposure.  With frost!

Comet Lovejoy Jan 15, 2015. STL11000 on Tak FSQ 106. 5 min exposure. With frost! Click for larger image.

The third try for Lovejoy was one of those completely abortive observing nights that nobody ever admits to. I planned to use the Canon at 100 mm piggybacked to get Lovejoy with the Pleiades, while exposing the STL11k for the coma and tail. First, the nut that holds the Canon to the mount had come loose and disappeared, and a spare was not immediately at hand. So, I scratched that part of the plan. Then, I could not find Lovejoy in the STL! I had collected coordinates in the house, punched them in, but no comet in the exposure. So I went online in the hut to get updated coords, tried them, and no comet. Tested the overall setup, and made a perfectly lovely, centered shot of Aldebaran. But I apparently had outdated comet info. It was around zero that night, and I was dressed for it, but my feet were getting cold and I was getting frustrated, so I hung it up for the evening with nothing to show for it.  That was about a week ago;  the forecast suggests that I may get another try on Thursday!

1 thought on “Comet Lovejoy trials and tribulations

Leave a Reply