I will probably make my first attempt to photograph C/2012 S1 ISON this coming weekend. A couple reasons for waiting… The bright Moon will have moved out of the morning sky by then. The comet, currently around magnitude ten, is brightening rapidly.
On the other hand the comet is plunging towards the Sun, rising later each day. Wait much longer and the photographic opportunity will slip away, at least until after Thanksgiving, when the comet will again appear after perihelion.
In the meantime, one of my favorite comet photos from years past…
Comet C/2007 N3 Lulin on the morning of 22 Feb 2009
Another frame of Comet Lulin taken from the driveway. This one was taken on the evening of the 26th, a day after opposition, when the comet was directly opposite the sun in the sky. The interesting ion tail that was to the west of the nucleus has swung around behind the coma from our point of view. The frame was aligned on the comet as it moved and processed to suppress the streaked stars.
Comet C/2007 N3 Lulin on the evening of 26 Feb 2009, a stack of 10 x 4 min exposures, Canon 20Da and TeleVue 76mm APO
The clouds have not been kind to those of use hoping to observe a comet here in Hawai’i. Last night Deb and I were at the Mauna Kea VIS, volunteering with the evening stargazing. I had hoped to get a good look at the comet from a dark site. But the clouds kept me from seeing the comet at all. A few people did get a look when a hole in the clouds allowed a glimpse, but by the time I got to an eyepiece the clouds had again closed over Leo, obscuring the view.
I did get a few hours of decent skies a few nights ago from the driveway in Waikoloa. I took advantage of that time to get twenty four minute exposures with the Canon 20Da and forty exposures with the CCD camera. Unfortunately the streetlights precluded my getting a decent visual view. The camera did a bit better, revealing some interesting structure to the tail.
Processing the image proved to be quite a challenge. The comet is moving very fast against the background stars. Aligning the images on the stars turns the comet into a long blur, likewise aligning the images on the comet creates streaks in place of stars. The answer is to process the image both ways and add the two resulting frames together as layers in Photoshop. This is the first time I had attempted this process and the results are reasonable…
Comet C/2007 N3 Lulin on the morning of 22 Feb 2009
