Astro-Photography Without a Telescope - 11

Our latest observing night at Macarthur Astronomical Society (Sat 5th January) was ruined by clouds yet again. After a clear day and predictions of a clear night, the clouds increased at sunset, leaving 50% clear skies for a while before wiping us out completely after 11 pm.

Southern vista with constellations of Carina, Hydrus & Tucana.

But I got a comet!

Barely visible, it would definitely have been missed if I wasn't deliberately searching for it.

I had read about the visibility of K5 Linear on Ian Musgrave's very informative amateur astronomy blog site, Astroblog. Ian also posted a trajectory map which enabled me to pinpoint exactly where to find the comet. The question I was asking myself was whether I would be able to pick it up using a camera mounted on a tripod (and Polarie mount).

I used three lenses, 10-24mm, 50mm and 135 mm to zoom in.  

Comet C/2012 K5 Linear taken with Canon 60D, 50 mm lens, f/1.4, ISO800, 150 sec. (Click to ENLARGE).

Above is the cropped image taken using a 50 mm f1.4 lens and it was just visible. After that, things went a bit wrong. The two bright stars in the above image are Iota Auriga (mag 2.7) and Elnath (Beta Tauri) (mag 1.65). In replacing the 50 mm lens with the 135mm lens, I lost my bearings and centred on Iota Auriga instead of Beta Tauri and lost the comet on all further images except just one, which showed it, right at the edge:

Comet C/2012 K5 Linear taken with Canon 60D, 135 mm lens, f/2, ISO800, 60 sec. (Click to ENLARGE).

Not only did the higher power camera lens pick up the comet's coma quite clearly, it also showed positive proof of orbital motion in the fifteen minutes since the earlier images. 

Note: images were taken from The Oaks, SW Sydney, looking northwards, directly through the Sydney metropolitan light pollution. The clouds were also hazy, so I am happy with the result!

:)