Vern's Weblog » Comets

Comet C/2008C1 (Chen-Gao) on Feb 10, 2008

Vern — Wed, 13 Feb 2008 20:51:52 +0000

Comet C/2008C1 (Chen-Gao) was passing through a beautiful star field with several small clusters when these images were taken. It showed up quite well through the eyepiece of 14 inch dob. The comet was in Cassiopeae. Estimated brightness is around magnitude 13.

Image was taken at dark sky site we call Roland’s Astro Corral on a private ranch in the Pawnee Grasslands about 40 miles east of Fort Collins, CO with Celestron Nexstar11, F3.3 focal reducer, and Astrovid Stellacam II video camera at 14/14 gain, integrate 128 (4 sec), acquired 40 frames for each image. Temperature was around 25°F, no wind, transparency was excellent, and turbulence was 6/10.

Comet 46P/Wirtanen on Dec 12, 2007

Vern — Fri, 14 Dec 2007 02:22:51 +0000

Comet 46P/Wirtanen is a short period (5.4 year) comet discovered in January 1948 by Carl Wirtanen at the Lick Observatory. According to the JPL Horizons Ephemeris it is currently magnitude 13.1, several other sites have it at magnitude 11.5 and 11.6.

Image taken from light polluted Louisville, CO with Celestron Nexstar11 telescope, F3.3 focal reducer, and Astrovid Stellacam II video camera (9/14 gain, 128 integration (4 sec), 0 gamma), 30 frames taken at 6:29 to 6:31 pm and 6:40 to 6:42 pm. Images flat field corrected, dark subtracted, aligned, stacked, and histogram adjusted with Registax4. Two resulting images were then aligned, text added, brightness adjusted, cropped, and animated with Photoshop Elements2. Sky was mostly clear, temperature 29°F, no wind, high humidity, transparency very good, and poor turbulence, maybe 4/10.

Comet 8P/Tuttle on Dec 9, 2007

Vern — Wed, 12 Dec 2007 00:27:50 +0000

Comet 8P Tuttle is predicted to brighten to about magnitude 6 in early January. Its currently maybe 9.8 or so. My third try on this one. Its getting a bit further south now so its a bit easier for those of us with equatorial mounts than it was last month.

Image taken from light polluted Louisville, CO with Celestron Nexstar11 telescope, Meade F3.3 focal reducer, and Stellacam II video camera, 9/14 gain, 128 frames integration (~4 sec exposure). Registax4 used to dark subtract, flat field correct, align, and stack 30 frames, 75% quality, #2 wavelet at 2.4 to sharpen slightly, histogram corrected from level 8 to 200. Enhanced, aligned and animation created with Photoshop Elements2.