Special Ed
Post Laureate
Reged: 05/18/03
Posts: 3531
Loc: Greenbrier Co., WV 38N, 80W
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Here is an inverted view.
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Michael Rosolina
8" f/10 Orange Tube SCT
4.25" f/4.2 Astroscan Reflector
SVP 3.6" f/13.6 CA Reflector
40mm PST f/10
APM Germany HD 15x70 binoculars
Canon 12x36 IS II binoculars
Mark I Eyeball
My CN Gallery
Edited by Special Ed (10/31/07 06:19 AM)
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rusirius6278
Carpal Tunnel
Reged: 11/03/06
Posts: 1722
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i just came in from observing this comet for several hrs. with 3 other club observers thru 2 Apos.
1st, in our observations this night, it appears that, as stated earlier, this comet indeed has lost most of it`s yellowish color...replaced by mostly a greyish/green...
2nd, because the comet`s halo is spreading out/becoming more diffuse, etc., as also stated earlier in the thread, it appears to us like it`s becoming dimmer at the same powers i was getting excellent views with just a few nights ago...i`m finding that i`m having to go to lower powers to get the same best/sharp, clear and detailed views i`ve been getting...just different colors now... 
so, if someone`s losing any detail, try looking at the comet at lower powers...this works great for us. 
and, as Phillip Creed also reported tonight, the low surface brightness is causing the halo to become extremely faint and almost impossible to see at powers above 115x...for this reason, i stuck to powers ranging from 32x to 88x thru my new Vixen ED103S tonight with excellent results/detail.
i note here that at 32x, to our eyes, the comet looks almost as huge as Jup at opp. this past summer, using 200x.
last, we also saw the other point/points of light and thought that the nucleus had broken up at 1st...but observing the comet about an hour later, it was obvious that these 2 other points of light were stars as they had moved out of the inner coma...and as Dave M.`s pic clearly shows...
these are just some of our observations here tonight...hope they are of some help/use to someone, etc...
Jim
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current scopes
Vixen ED103SWT
Vixen ED102S
C-102AZ/HD
StarMax 127
Jason 60/11.7
UO HD Abbe Orthos - 5mm, 6mm, 7mm, 9mm
Older UO Ortho - 4mm
Celestron 2x Ultima Barlow
and many other scopes i`ve been fortunate enough to check out...
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David Knisely
Postmaster
Reged: 04/19/04
Posts: 6784
Loc: Beatrice, Nebraska
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Well, I just had a nice view of the comet coming out of work tonight. It is non-stellar to the unaided eye, but is small enough to be easily mistaken for a star. It is a tad fainter than previous nights, but I would still put it around magnitude 2.6 or so. It is quite sizable, although its size increase appears to be slowing. The color was similar to last night (a dirty yellowish hue). I did a quick transit timing of the brighter main shell of the coma in my 100mm f/6 refractor and found it to be around 7.1 arc minutes in diameter, with a *very* faint outer halo not quite twice this size. The "annular effect" was fairly noticeable in the main coma, but from doing an analysis of some images, it appears that it might be somewhat illusionary and perhaps not really a true feature. What we see is a rise in brightness at the outer edge of the coma which quickly flattens somewhat into a sort of weak "plateau" of brightness with decreasing distance from the nucleus before rapidly increasing again as one approaches the middle of the coma. This is similar to what I have seen in some "disk" planetary nebulae where annularity is suspected but not confirmed in later analysis. There is the brighter broad central "fan" just south of the geometric center of the coma, and there are subtle hints of structure at the limits of visibility including some darkening on the side of the nucleus opposite the fan. The nuclear condensation remains stellar. I did note a couple of faint stars in the coma, undoubtedly those which had been mentioned on some of the boards as "splitting nucleii". One was approaching the eastern edge of the coma, and it was somewhat brighter than the nuclear condensation was. I dropped the power in my 100mm f/6 and looked for any signs of a tail, but I didn't see any. Clear skies to you.
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David W. Knisely
Hyde Memorial Observatory
http://www.hydeobservatory.info
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Gynomite
sage
Reged: 06/06/06
Posts: 245
Loc: Dallas Texas
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I agree. It seems to be fading in magnitude. It appeared to be less bright than delta Per tonight.
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Celestron NexStar 6 SE SCT
Orion 12XTi Dob with COL (SOLD)
Celestron Sky Scout
Denk Big Easy
Denkmeier P x S Diagonal
Orion Stratus 68 5mm
Orion ED 2 12.3mm (paired)
Orion Lanthanum 21mm (paired)
Leupold 12x26 Binoculars (Hunting and Birding)
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Tuugii
professor emeritus
Reged: 03/22/07
Posts: 522
Loc: Ulaanbaatar, Mongolia
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I am writing from the dome of 21", just got an visual 20min view through 34mm EP. The comet had traveled a lot so I am already late to image the bright stars through the diffuse glow.
According to the starrynight, the two bright stars were:
TYC3334-788-7/the brighter one/ ----------------- +9.21m_v
TYC3334-738-1-------------------------------------- +10.84m_v
The comet looks even more diffuse, the outer shell is expanding so rapidly that it had already covered the field of view of my Canon Xti camera through 21", but now it is close to cover all the field of Meade 34mm 5000series EP. On the other hand the brightness of the shell is decreasing rapidly, so for most observers it will be better on low magnifications.
The core is bright as previous, but visually it is obvious that the comet had dimmed pretty much, I estimate it as about +2.8m_v.
Tuugii
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telescope=time machine...
Edited by Tuugii (10/29/07 04:05 AM)
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photonovore
Moonatic
Reged: 12/24/04
Posts: 2472
Loc: tacoma wa
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Took another look again tonight (two clear nights in a row, the gods are kind). Definitely seems dimmer tonight. The differentiation between the coma and outer nebula appeared much less distinct, with the brighter cometic area more fan shaped than previously. The central condensation also appeared somewhat less stellar and somehow softer than last evening and the outer nebulous "shell" seemed less defined as well, with the edges irregular, almost ragged on the trailing hemisphere. There is a brightening of the advancing hemisphere on its boundary, which remains well defined to my eye; that it may be illusory is certainly possible, although some recent images show this brighter boundary area rather distinctly. I too found that lower mags (i used 40 and 90x) seemed to give the best defined visual appearance. Both the coma and the outer nebula seemed mottled...the brighter cometic area had a distinct dark "lane" running from the central cond. back into the fan that i noticed. The Moon is certainly not helping improve the internal contrast of this comet... Altogether a very interesting visitor-- hopefully, with cooperative wx, i'll get another few looks.
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Mardi
4" achromat, ETX-70.
Whitepeak Lunar Observatory Website
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novbabies
Postmaster
Reged: 06/05/05
Posts: 15678
Loc: Northern Georgia!
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3:14 AM 10-29-07 Athens GA - comet continues to impress. We have been blessed with clear skies every observing opportunity but one during this fantastic apparition! Still brighter than 3.01 mag Delta Per by naked eye. Moon is still quite close (maybe within 30° or so) but waning. The comet is more strongly centrally condensed in 7x35 binoculars. Unless the moonlight is causing this, the comet is DISTINCTLY less yellow than early in this brightening. Anyone else notice that? This morning, extending a line from Del Per through the comet a little more than the distance between Del Per and the comet brings me to a group of stars that strikingly resembles the constellation Corvus!
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Good Seeing!
Mark
Orion 12" XTi f/4.9
VERY old Edmund 6" f/8 reflector
Assorted binoculars
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novbabies
Postmaster
Reged: 06/05/05
Posts: 15678
Loc: Northern Georgia!
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Quote:
Great pictures and reports, everybody.
Could somebody, please, help me to find the comet at my picture. Is it, where I put question mark? Thank you.
Yes, here is one of mine from 10-27-07 for comparison; comet is right next to that tree top:
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Good Seeing!
Mark
Orion 12" XTi f/4.9
VERY old Edmund 6" f/8 reflector
Assorted binoculars
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novbabies
Postmaster
Reged: 06/05/05
Posts: 15678
Loc: Northern Georgia!
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With the multitude of pix available, it would be pretty amazing to gather, collate, orient, and create a movie of the comet's apparition... 
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Good Seeing!
Mark
Orion 12" XTi f/4.9
VERY old Edmund 6" f/8 reflector
Assorted binoculars
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Jeremy Perez
Carpal Tunnel
Reged: 08/12/04
Posts: 1675
Loc: Flagstaff, Arizona, USA
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To my eyes, the comet has now taken on a sort of off-white newsprint color. The large, faint outer halo fades out softly and high thin clouds made it more difficult to hunt for specific patchiness in this structure. The coma was still brilliant, but its edges are showing more distress. The northeast side is sharper, while the southwest side appears to have a more gradual fade out. All around, the edge of the coma has a sort of raggedy, hairy appearance. The central fan structure still points roughly to 220 degrees PA and continues to grow softer. On the opposite side of the pseudo nucleus, the fan wraps around and makes a subtle fork. The annular appearance of the coma is still hard to shake, and although I feel pretty sure that it is an illusion, I am suggesting it in the sketch because it gives that impression visually. I noticed three stars embedded in the coma at high power. The low power view was a beautiful sight with a number of bright stars framing the comet. Astrometric eyepiece measurements from tonight yielded:
Central condensation: 1.7 x 1.2 arc minutes
Coma: 6.7 arc minutes
Outer halo: 17.8 arc minutes
To the naked eye, the definite disc-shape continues to become more obvious, although still tiny. I think it's going to be a pretty compelling naked eye sight when we get to new moon in less than a couple weeks.
The full report, labeled and high-res sketches from tonight can be found here.
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Orion SVP 6LT (6" f/8 Newt) || Orion XT8 (8" f/6 Newt) || 15x70 Oberwerk Binoculars
The Belt Of Venus || Astro-Sketch Gallery || Astro-Sketching Resources || Astro-Photo Gallery
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Jeremy Perez
Carpal Tunnel
Reged: 08/12/04
Posts: 1675
Loc: Flagstaff, Arizona, USA
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...and the 120X sketch...
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Orion SVP 6LT (6" f/8 Newt) || Orion XT8 (8" f/6 Newt) || 15x70 Oberwerk Binoculars
The Belt Of Venus || Astro-Sketch Gallery || Astro-Sketching Resources || Astro-Photo Gallery
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14687
Loc: Hurricane Alley
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Quote:
To my eyes, the comet has now taken on a sort of off-white newsprint color.
That's exactly how I would describe it as well.
Great reports and sketches Jeremy, as always. 
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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Ziggy943
scholastic sledgehammer
Reged: 08/11/06
Posts: 827
Loc: SLC, UT
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Quote:
Well, I just had a nice view of the comet coming out of work tonight. It is non-stellar to the unaided eye, but is small enough to be easily mistaken for a star. It is a tad fainter than previous nights, but I would still put it around magnitude 2.6 or so. It is quite sizable, although its size increase appears to be slowing. The color was similar to last night (a dirty yellowish hue). I did a quick transit timing of the brighter main shell of the coma in my 100mm f/6 refractor and found it to be around 7.1 arc minutes in diameter, with a *very* faint outer halo not quite twice this size. The "annular effect" was fairly noticeable in the main coma, but from doing an analysis of some images, it appears that it might be somewhat illusionary and perhaps not really a true feature. What we see is a rise in brightness at the outer edge of the coma which quickly flattens somewhat into a sort of weak "plateau" of brightness with decreasing distance from the nucleus before rapidly increasing again as one approaches the middle of the coma. This is similar to what I have seen in some "disk" planetary nebulae where annularity is suspected but not confirmed in later analysis. There is the brighter broad central "fan" just south of the geometric center of the coma, and there are subtle hints of structure at the limits of visibility including some darkening on the side of the nucleus opposite the fan. The nuclear condensation remains stellar. I did note a couple of faint stars in the coma, undoubtedly those which had been mentioned on some of the boards as "splitting nucleii". One was approaching the eastern edge of the coma, and it was somewhat brighter than the nuclear condensation was. I dropped the power in my 100mm f/6 and looked for any signs of a tail, but I didn't see any. Clear skies to you.
Pretty much the way I see it also.
Is there a geometrical explanation of why we see no tail?
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Siegfried
4" Mak
160mm F8 TEC (born 1-18-2007, 27 lbs, 45.5" long), on AP900
150mm F17.5 (D&G lens) (first light 6-7-2008)
9" F/14.8 Alvan Clark (1915), on Byers 812
14.25 F/5.5 Newt in a roll off observatory
Others, that have come and gone
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ForgottenMObject
Post Laureate
Reged: 09/11/04
Posts: 3585
Loc: Maryland, US
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I think the tail is facing away from us (approximately) as the comet heads outwards, away from the Sun.
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Matthew
IDA member
XT8i, 10x50 binoculars, lots of eyepieces
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gogolplexer
super member
Reged: 06/04/07
Posts: 109
Loc: Toronto, Canada
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The Earth is roughly between the Comet and the Sun as it moves away from us. If there were any tail, it would be "behind" the comet from our viewpoint and so not visible.
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Orion 10XTi with COL
Celestron 80ED on EQ-3
27mm Panoptic
20mm TV Plossl
12mm NaglerT4
7mm NaglerT6
Visual Paracorr
3X TV & 2X Celestron Ultima Barlows
10x50 Orion Vista binocs
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BigWingBoy
member
Reged: 10/07/07
Posts: 31
Loc: Massachusetts, USA
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Quote:
I saw this too tonight. When checking the comet's position using StarryNights program, it shows a star next to the nucleus. At the moment my assumption is that it is this star and not a split nucleus. The star is: TYC3334-788-1 @ Mag 9.
[EDIT 10:23 ET] -- I just did a second check and positionally this second spot within the comey does correspond to the position of where TYC3334-788-1 should be. Apparent brightness of the spot also corresponds with similar magnitude stars in the region.
I shot almost the exact same image Sunday night. Am I correct that what we're seeing is actually background stars and not the comet itself? Can we see the actual comet body at this distance?
Gene
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Jeff Young
Post Laureate
Reged: 08/04/05
Posts: 3169
Loc: Ireland
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I was on the run a bit last night, but I was able to grab a quick 20min to do a sketch in between two parties.
10/28/2007 20:30 UT I found 4 background stars embedded in the comet (one at the very edge). I still see the annular characteristic, although it has faded at the WSW edge. The fan has become much more circular and less fan-shaped, and its edges considerably softer. I still see a dirty yellow color, but it is very muted now.
The sky was *far* more transparent last night, leading to 16 background stars in my sketch vs. 3 or 4 from previous nights. (Yes, the comet has also moved a bit, but many of the stars I recorded last night are much dimmer than the dimmest I was recording the previous nights.) Still, with the moon even closer I'm unable to see the faint outer halo.
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Nikon 18x70s / UA Millennium Colorado:
Solarscope SF70 / TV Pronto / AP400QMD Coronado SolarMax40 DS / Bogen 055+3130
APM MC1610 / Tak FC-100 / AP1200GTO Tak Mewlon 250 / AP600EGTO
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Psyire
sage
Reged: 06/24/07
Posts: 353
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I don't understand the whole tail theory...
Perhaps someone could explain it better?
If the comet has a period of roughly 6.5 years, then we should be gaining on it just as we are Mars. If we are indeed gaining on it, then it should change shape of some kind, no? Of course, maybe it's just that a few days aren't enought to notice the difference, perhaps a few weeks? I'm not an expert by any means, but this seems to make sense to me.
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Celestron CPC 1100 XLT, Sky-Watcher Equinox 80ED
TV 31T5-Nagler, 8&13mm-Ethos
EarthWin Binoviewers w/ 24mm Panoptics
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mbz
Post Laureate
Reged: 01/13/05
Posts: 4929
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This is one amazing comet and beautiful images, everybody. Thank you for sharing.
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canopus56
sage
Reged: 05/01/05
Posts: 298
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This is the second outburst in about 110 years which raises questions about the mechanism of action causing the outburst, e.g. - if it repeats it is less likely to be an collision impact.
Edwin Holmes discovered this comet during an outburst similar to the current event on Nov. 14, 1892. Read his 1892 report of the discovery.
http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1892Obs....15..441H
Gary Kronk's Cometography webpage with an extensive review of the history of this comet going back to the 1800s.
http://cometography.com/pcomets/017p.html
- Canopus56
P.S. - The Hubble Space Telescope scheduled time this morning (12:18 UTC) to image Comet 17P. Nothing on when an image might be released.
http://www.stsci.edu/ftp/observing/weekly_timeline/timeline_10_29_07
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