Conditions: acquired 3 miles north of Boulder, CO, on Apr. 27, 2004 with a moderately light polluted sky, 5-15 minutes before start of nautical twilight; ~10 deg. C, weak western wind, no clouds, good/average transparency. The altitude of comet Bradfield during the exposures ranged from 9-11 degrees; pretty low! Visually, I couldn't see a thing!!
Setup: Nikon 180 mm F4, DF-2 focusser, IR reject filter, ST10XE, MaximDL/CCD, Takahashi EM-10 mount (see a mechanical description and roadside view of this setup)
Exposure time: 15x25 sec. Could have used more time, but I wanted to get comet Linear too, and the sky was rapidly brightening!
Processing (Mira, Registar, Photoshop): dark subtracted, flat fielded, masked hot/cold pixels, subtracted bright sky background (3x3 polynomial fit), registered, median/avr combined (in Registar), levels&curves, reduced 50% for web format
Notice the very small anti-tail jutting out from the coma! - I wonder if this is real? This image was fun to take, driving out of town at 2.30 am, setting up at the side of I-36,
getting checked out by a cop, imaging for 10 minutes - over! On to comet Linear. I was lucky with the good weather, there were basically just 2-3 optimal
nights for getting these two comets from my location.
Here's my main page where you can see more of the pictures I have taken so far.
Comments greatly appreciated! (mikael@leif.org)
