Wednesday, January 21, 2015

Beginning the year with Comet C2014 Q2 (Lovejoy)

In January the big deal in astronomy, at least for amateurs, has been seeing and imaging Comet Lovejoy -- technically: C2014 Q2 (Lovejoy). The comet was a (barely) naked-eye object under the clearest skies but its appearance was glorious in the best images made of it. In the best images a long, smoke-like tail streamed off a globular head or nucleus against a beautiful field of stars. The most distinctive feature of this visitor to the inner solar system, however, was its green appearance, seen in even the crudest of photographic images -- mine included!

Weather has been largely uncooperative for comet-watching from Northeastern Ohio with most nights in January being impossibly cloudy. On the rare clear night, temperatures were usually in the frigid teens; enough to scare off all but the bravest, most hardy observers and imagers. On one cold night I noticed the sky was clear of most clouds; bands of cloud were drifting across from north to south. It looked like I might have a limited opportunity for photography. I quickly set up my camera, 400mm lens and tripod and tried some imaging hoping that, without tracking, I could pull something from my efforts.

Photo: C2014 Q2 (Lovejoy) by James Guilford
Comet Lovejoy is the lovely green "fuzzball" located left of the center of this photo. Canon EOS 50D: ISO 1250, f/5.6, 6 sec., 400mm (600mm equiv.), January 16, 2015 @ 11:02 PM EDT. Photo by James Guilford.

Comet Lovejoy was easy to find with binoculars located, as it was that night, directly "down" from The Pleiades star cluster in the western sky. I could even make out the comet's faint smudge in the viewfinder of my single-lens reflex camera; the comet was at or near its brightest for this apparition! After perhaps a dozen shots at different shutter speeds and refocusing a time or two, I fled indoors and stowed my gear to let it warm to room temperature. Looking at the tiny images in the camera's internal LCD panel, I was hopeful. I was disappointed later when, reviewing the images on the computer's mammoth screen, I could see star trails that would cause me fits.

The image shown above resulted after a lot of effort, seeking the best way to remove star trails from the image. In the telephoto view, the stars "moved" significantly in the six seconds of the exposure. Using Photoshop, I masked out most of the trails and, in so doing, lost much of the image brightness and many dimmer stars. I immediately wished I'd have taken the time and frostbite risk and set up, at the very least, one of my telescopes' mounts with tracking capability.

Simulated view of C2014 Q2 and star field showing it amongst stars at the edge of constellation Aries as they appeared at the time the photographic image was made. All are "minor" stars without common names. Sky Safari +

So, I learned (and re-learned) a couple of things that I hope to remember and act upon:

  • Longer focal length magnifies the apparent motion - don't get greedy, a 200mm lens would have made a better photo in this case; I could have included The Pleiades!
  • Set up the telescope tracking drive if there's any opportunity to do so! A good alternative (that I intend to pursue) is a simplified "star tracking" device intended for cameras; I'm considering three available devices that are faster to set up than telescope mounts.
C2014 Q2 won't return for about 8,000 years so, while I'm sad I didn't get better photos of my own of that lovely visitor; I'm happy to have seen it with my own eyes!