Images have been pouring in from around the world of this most photogenic comet, which is already around 4th magnitude and visible in the night sky of the northern hemisphere. After many frustrating evenings of cloud hopping, or being completely defeated by the inclement weather, or having the comet’s delicate tail features drowned out by a full Moon, our turn came round on Monday the 12th of January.
The normal best options of Tebay Road and Shap Summit were forecasting winds gusting to 30 and 40 mph, and looked as though they would be clouded over earlier than more northerly locations. Keswick, in the north of the Lake District, showed great promise on the forecast charts – and there is a beautiful location above the town which is home to the Castlerigg Stone Circle. The forecast here was for gentle breeze and cloudless skies from twilight to about 9pm.
After about an hour’s drive it was pedestrian access only, through a narrow gate on a strong spring, so it took several trips from the parked car to set up the tripod, mount, telescope, camera and all the bits and bobs that make up an astrophotography session. The sky looked clear as the light faded, and Lovejoy was clearly visible to the naked eye before full darkness at 18:36.
The new alignment routine for the mount was really straightforward, and the handset reported alignment to within ten arc minutes in altitude and azimuth. That’s enough for the exposure needed, so I hooked up the camera and started.
First off, a series of frames through the 300mm lens, which stacked nicely to reveal some good detail in the comet’s tail.
To be really critical, there are some major defects in this photo. The ambient light from the nearby town caught the humidity in the air and presented a layer of faint light – invisible to the eye – that blurred in the wind across the long exposures. It can be seen as a scratchy effect right across this photo. I last saw this phenomenon when I took summer photos of Comet C/2011 L4 (PANSTARRS) passing Yildun from my back yard in June 2013. At the time I thought this might be a combination of light, moisture and wind, and now I’m sure of it. This defect also made replacement of the stars – eliminated by the comet processing – less satisfactory.
By the time I have collected enough of these frames the clouds are creeping in, so I switch to using the Nikon straight through the telescope, effectively an 805mm lens. Some of the effect of the ambient light is eliminated by this move, but the result is still less than totally satisfying. Several of the frames had to be discarded as they were degraded by cloud interference.
It is interesting to think that a couple of years ago, I would have been blown away by the thought that I could take photos like these. Now, with greater experience and understanding of the techniques, I cannot help but see the imperfections. That falls somewhere between a disappointment and a really exciting challenge!