A comet that probably shouldn’t have survived its close encounter with the Sun last week appears made it out alive. If ailing a bit. C/2015 D1 SOHO, discovered in photos taken by the Solar and Heliospheric Observatory (SOHO), somehow stayed together in one piece after its near-death solar pass.
This photo taken on Feb. 25 in late evening twilight by geologist and amateur astronomer Justin Cowart of Alto Pass, Illinois, is the first of the comet’s ghostly remnant. It was taken on Feb. 25 during late evening twilight. Cowart didn’t have much hope after hearing speculation that the comet may have been “ISON-ized”. In late 2013, Comet ISON frittered away to little more than an expanding cloud of dust after a similar close pass by our star.
But rather than give up, he set up a camera and tracking mount and waited for the sky to clear in the west after sunset Wednesday evening. Comet SOHO was then located about 10° above the horizon near the star Theta Piscium at the time the photo was taken.
“I was able to see stars down to about 6th magnitude in the raw frames, but no comet,” wrote Cowart. “I decided to stack my frames and see if I could do some heavy processing to bring out a faint fuzzy. To my surprise, when DeepSkyStacker spit out the final image I could see a faint cloud near Theta Picsium, right about where the comet expected to be!”
Stacking is a method of adding multiple pictures taken of the same object together to create a brighter, less grainy and more detailed image. Software programs make it easy.
Cowart sent the picture off to astronomer Karl Battams, who initially brought the comet into the limelight, for his opinion. Meanwhile, comet observer José Chambo got involved in the discussion and plotted D1’s position on a star atlas (in the blinking photo above) based on a recent orbit calculation. Bingo! Justin’s photo was dead on with the predicted position.
Two night later on the 27th, Jost Jahn of Amrum, Germany set up a small telescope and photographed the SOHO D1 which had by then moved a little higher in the western sky. No question about it – that’s the comet. But like the headless horseman in the Legend of Sleepy Hollow, it’s returned without its head! After a thorough toasting by the Sun, all that remains is an expanding, elongated dust cloud. ISON-ization indeed!
Watch Comet Lovejoy C/2011 W3 rise in this beautiful video by Stephane Guisard
Readers may remember that Comet Lovejoy (C/2011 W3) suffered a similar fate in late 2011, yet remained a remarkable sight in the dawn sky.
Inspired by Cowart’s possible capture, I set up my own camera two nights ago and photographed the comet’s position with a 200mm telephoto lens under a cold but very transparent twilight sky. Shot “raw” with no stacking, I’m not convinced the image shows a comet. It was still fun to give it a try, and I look forward to the moon leaving the sky next week for a go at seeing Comet SOHO D1 with a telescope.
Here’s a fresh map based on the most recent orbit published by the Minor Planet Center. Go out and give a try yourself at photographing it. Stacking images is preferred to enhance what’s obviously a faint and diffuse object. Cowart shot his photos between 60 and 70 minutes after sunset when the comet’s altitude ranged from 10° and 6° high. Mine were taken between 70 and 80 minutes after sundown.
Cross your fingers and make appropriate sacrifices to the god of your choice. The comet may be visible in telescopes as it climbs higher into a dark sky after the moon departs the scene around March 6-7.