So Kristin bought me a sweet new lens for my birthday, so I had to take it out tonight and get another shot of 17P/Holmes. It was mostly cloudy, but I was able to get a shot in a clear spot.
The base image is approximately twice the magnification (per pixel) as the previous image. I’ll do a comparison of the two images at similar scale in a bit here*, but I wanted to post this before it was too late.
17P/Holmes is expanding rapidly after the outburst, and according to SpaceWeather is now covering a volume larger than Jupiter. That’s pretty impressive for a week’s worth of expansion.
* Hmmm… unfortunately, this really isn’t as straightforward as I hoped. Although the lens provides an additional 1.95x in angular magnification, the exposures are completely different. I shot the original image with a 2 second exposure at f/5.6 at ISO100 on a 105mm lens. The second images is 1 second, f/2.8@ISO400 on a 200mm. That’s a factor of 8 difference in exposure so I obviously collected a lot more light from the the diffuse coma in the second shot than in the first. If I do future shots (and I expect I will), I’ll stick to 1,2.8,400 @ 200mm for easy comparison.
October 28th, 2007 at 10:26 pm
Happy (belated, now) birthday, bro! Hope you got my e-card. Hope it was a great day!