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: Updated November 18 - Comet 17P Holmes ASO Update  ( 10464 )
drclay
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« : November 10, 2007, 09:17:38 AM »

COMPLETE COMPOSITE IMAGES now posted (scroll to end) From Oct 25 Outburst to November 7 !!
(see NEW posting for observations beginning NOV. 10 2007) at:  http://www.arksky.org/smf/index.php?topic=1445.0

UPDATE November 18 - Latest Image at bottom of sequence
Arkansas Sky Observatory (H45) update on Comet 17P: 
Comet imaged in moonless skies, good conditions, perhaps last opportunity before moon interferes
The comet has continued to decrease in total brightness, both total and nuclear  as coma continues expansion;
Physical morphology NOT appreciably changed, and the overall size of the coma has grown only slight in past ffew days, developing tail streamers vividly in P.A. 209 deg.
with several parallel secondary tails seen in negative inset image.
Coma overall diameter = 13.9' arc (CCD)
Coma appears very large and now is very diffuse and difficult to the naked eye, estimated at about 22 arc minutes
Magnitude, m1 = 3.4, (naked eye) very difficult and large to the naked eye, colorless  and NOW appears to have totally lost the previous distinct yellow color; comparison star (naked eye) is Alpha Per
Nuclear magnitude, m2 = 14.2, continues to drop rapidly as the nucleus becomes even more pinpoint

Overall color is now colorless, and therefor this image is has been taken in monochrome.

Equipment: 0.4m SCT @ f/3 CCD, ST402-ME C-I CCD, 50 seconds.  Overall magnitude
estimate via naked eye, Alpha Per. by comparison.


UPDATE November 12 - Latest Image at bottom of sequence
Arkansas Sky Observatory (H45) update on Comet 17P: 
Comet imaged in moonless skies, good conditions, perhaps last opportunity before moon interferes
The comet has continued to decrease in total brightness, both total and nuclear  as coma continues expansion;
Physical morphology NOT appreciably changed, and the overall size of the coma has grown only slight in past ffew days, developing tail streamers vividly in P.A. 209 deg.
with several parallel secondary tails seen in negative inset image.
Coma overall diameter = 15.9' arc (CCD)
Coma appears very large and distinct to the naked eye, perhaps as much as 25 arc minutes
Magnitude, m1 = 2.9, (naked eye) nearly equal to previous night, very distinct cloud to the
naked eye with conspicuous nebulosity and NOW appears to have totally lost the previous distinct yellow color; comparison star (naked eye) is Alpha Per
Nuclear magnitude, m2 = 13.6, continues to drop rapidly as the nucleus becomes even more pinpoint

Overall color is now colorless, but somewhat blue.

Equipment: 0.4m SCT @ f/3 CCD, ST402-ME C-I CCD, RGB @ 40 RGB seconds.  Overall magnitude
estimate via naked eye, Alpha Per. by comparison.


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« : November 19, 2007, 08:33:47 PM drclay »

Dr. Clay
drclay@tcworks.net
ASO Petit Jean Mountain /MPC H41
ASO Petit Jean Mountain South /MPC H45
ASO West Conway /MPC H43
.......serving astronomy since 1971
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