Astrophotography Gallery (by Igor Chekalin)
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17P/Holmes comet outburst. Day 4.

   Spectacular cosmic show... must go on! :) Unfortunately i've missed 3rd day because of cloudy weather. On Oct'27 evening, awaitings of opening in clouds was rewarded with about 20 minutes of relatively cloudless comet visibility. Coma still grow in size, but getting fainter, allowing 30-sec iso100 exposures without center saturation. Now the size of the bright part of coma is about 4.6 arcminutes. Supposed 20-minute exposition was stopped after 5 minutes because of  returning clouds. So i've got only 11 30-sec frames and one 5min. But this was surprisely enough not only to get coma details, but also to reveal faint greenish halo around the comet (possible oxygen emission?). 
   Some clouds are visible in background of the picture.

Comet explosion. Day 4. Size 33%

Crop, 66% size

Optics  Mizar TAL-1  (4.4" Newton F=800mm 1:7.3)
Exposure Details HDR commposition of one 5min and 11x30sec expositions. @ iso100
Mount EQ6 PRO SynScan equatorial mount.
Camera/Guider Canon 350D (modified with Baader IR-cut filter.), Guider camera is QHY6 CCD.
Filter none
Date Oct 27, 2007, 16:15(UTC)
Location Center of 300k pop. town.

2000-2007 All images, text and software are copyright Igor Chekalin