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Posted by: Stu Jan 6 2007, 05:28 PM

This has been in the news for a week or so now, with many "experts" predicting it might become very bright around Jan 8-10th in the evening sky as seen from the n hemisphere.

And, after several nights of wasting my time and freezing my fingers off, I'm happy to be able to report my first sighting of Comet McNaught!! Frustrated by great black pillows of cloud in the comet's direction last night, but a very clear WSW horizon tonight lured me back up the sloppy-mud covered track that leads up to Kendal Castle, and from there, at 16.49, I got my first glimpse of the comet. Phew!!

It wasn't visible to the naked eye - well, not my naked eye, anyway - but it is very, very easy to see in binoculars, its head a star-like point and an obvious (and very straight, I thought...) tail stabbing away from it at almost a 45degree angle. The head looked orange-yellowish in my 10x50s, and there seemed, when using averted vision, to be quite a fan-shaped tail sweeping to the upper right. Unfortunately I didn't get to see the comet in a darker sky because it started playing hide and seek behind several horizontal bands of cloud, but my last sighting of it this evening, at 17.05, was very nice... orange-grey sky, streaked with lines of cloud, and Comet McNaught glinting above them like a spark.

Here's hoping others had some luck tonight too!

Posted by: Sunspot Jan 6 2007, 05:51 PM

Has anyone here managed to spot this potentially brilliant comet? It's VERY low in the sky after sunset or at sunrise but pretty bright. It will make a particularly close pass of the Sun and there are some suggestions it could be visible in daylight to the naked eye for a few days

http://skytonight.com/observing/highlights/5089276.html

Posted by: Myran Jan 6 2007, 06:02 PM

I will always remember comet Hyakutake myself, it was the main comet of the last century. It was clearly visible naked eye even with surrounding city light and we did drive off about 2 km near the city limit and there we could see it was spanning half the sky. Before that I always thought the medieval depictions of large comets in the sky had been one exaggeration. But I was wrong, and luckily so.

Good that you spotted the comet eventually then, your work wasnt for naught then.

Posted by: Stu Jan 6 2007, 06:07 PM

QUOTE (Sunspot @ Jan 6 2007, 05:51 PM)

Posted by: Sunspot Jan 6 2007, 06:53 PM

Nothing seen here... but it has been raining ALL day

What did it look like? Was it easy to see?

Posted by: nprev Jan 7 2007, 02:10 AM

<clink, clink, clink> southern California light pollution & smog...I couldn't find it, despite clear skies. Maybe I'll try for a daylight sighting tomorrow; seems like there's a bare possibility for this.

Posted by: Mongo Jan 7 2007, 03:40 AM

Here is a list I made for my own amusement some time ago, of the greatest naked-eye comets of the last two centuries, visible to observers in the northern temperate regions. I used a points system as follows:

MAGNITUDE: 10 points for every degree of magnitude brighter than +3 (dark-sky; daytime magnitude gets counted separately)

TAIL: 1 point for every two degrees of length of naked-eye visible tail in dark sky

DURATION VISIBLE: 1 point for every month naked-eye visible in dark sky

BONUS POINTS:
2 visible tails = 10 points
5 visible tails (West 1976) = 20 points
15 degree long anti-tail (Arend-Roland 1957) = 10 points
curved tail (Donati 1858) = 5 points
'bright' tail (Daylight 1910) = 10 points
'brilliant' tail (Ikeya-Seki 1965, Great September 1882) = 20 points
circumpolar all night (Hyakutake 1996, Tebbutt 1861) = 10 points
Mag. -3 in daylight (West 1976) or Mag. -5 in daylight (Daylight 1910) = 10 points
Mag. -8 in daylight (Great March 1843) = 15 points
Mag. -15 in daylight (Ikeya-Seki 1965) or Mag. -17 in daylight (Great September 1882) = 30 points

1861 123 pts Tebbutt
1882 101 pts Great September Comet
1910 95 pts P/Halley
1976 90 pts West
1996 78 pts Hyakutake
1997 73 pts Hale-Bopp
1858 68 pts Donati
1965 64 pts Ikeya-Seki
1970 61 pts Bennett
1957 57 pts Arend-Roland
1910 54 pts Daylight Comet
1811 52 pts Great Comet
1843 50 pts Great March Comet
1874 46 pts Coggia
1881 42 pts Great Comet
1807 37 pts Great Comet
1853 37 pts Klinkerfues
1835 35 pts P/Halley
1957 35 pts Mrkos
1860 31 pts Great Comet
1911 29 pts Beljawsky
1911 28 pts Brooks
1819 25 pts Tralles
1854 24 pts Great Comet

Here is the same list in reverse chronological order:

1997 73 pts Hale-Bopp
1996 78 pts Hyakutake
1976 90 pts West
1970 61 pts Bennett
1965 64 pts Ikeya-Seki
1957 57 pts Arend-Roland
1957 35 pts Mrkos
1911 29 pts Beljawsky
1911 28 pts Brooks
1910 95 pts P/Halley
1910 54 pts Daylight Comet
1882 101 pts Great September Comet
1881 42 pts Great Comet
1874 46 pts Coggia
1861 123 pts Tebbutt
1860 31 pts Great Comet
1858 68 pts Donati
1854 24 pts Great Comet
1853 37 pts Klinkerfues
1843 50 pts Great March Comet
1835 35 pts P/Halley
1819 25 pts Tralles
1811 52 pts Great Comet
1807 37 pts Great Comet

Bill

Posted by: nprev Jan 7 2007, 03:57 AM

QUOTE (Myran @ Jan 6 2007, 10:02 AM)

Good that you spotted the comet eventually then, your work wasnt for naught then.

Posted by: Mongo Jan 7 2007, 04:32 AM

QUOTE (nprev @ Jan 7 2007, 03:57 AM)

Posted by: nprev Jan 7 2007, 05:04 AM

I've seen that rendition of the 1744 comet before...even more impressive when you consider that it's a recollection (probably from memory) of a naked-eye observation!

Sure hope that the Kreutz group has a few more of these in store...but, sadly, is this a realistic possibility? My impression is that most of the major fragments from the original Kreutz body (errant KBO, I presume), passed perihelion during the middle part of the last millennium.

Posted by: Mongo Jan 7 2007, 05:26 AM

There is a chance that Comet McNaught might make that list too. there have been 24 Great Comets in the past 200 years, for an average interval of 8.3 years, and the last Great Comet (Hale-Bopp 1997) was at its most impressive almost 10 years ago. Of course, this means nothing in practical terms -- but we are 'due' for another one.

Here is what comet expert John Bortle has to say about McNaught 2007:

START QUOTE:

As is usually the case for the physical development of a given comet with approach to perihelion, many variables are involved that can not easily be defined beforehand.

Because C/2006 P1 has been so poorly observed up until now, its absolute or intrinsic magnitude, as well as the variable "n", are still quite uncertain and the former figure is typically of great importance in the development of the tails (especially the dust tail). Likewise, particle size relative to sunlight pressure, heliocentric distance and the projection circumstances, all play major rolls in at least the dust tail's apparent length and curvature.

Should Ho be about magnitude 6.5 or fainter, then the dust tail is likely to be fairly weakly and with no more than a few degrees of its length visible in the bright twilight, initially projecting in the same relative direction as calculated for the ion tail around the time of perihelion. One might well expect an appearance similar to a somewhat enhanced version of Ikeya-Zang, or perhaps like Bradfield 2004 F4.

However, if it turns out that C/2006 P1 is actually a major comet, with an Ho around 5 or so, the situation could change rather dramatically (he says, taking a deep and hesitant breath!). In that case, a strong, high surface brightness dust tail is likely to form. And at the same time, tail projection circumstances and the small q should favor much of the length of any dust tail to almost overlap the ion tail for perhaps 1/2 to 2/3's the calculated span, before significantly curving off to the north.

Under the very best of circumstances, from a visual standpoint C/2006 P1 could become a truly spectacular object (especially when factoring in a major forward-scattering event), with possibly a degree or more of tail visible in the daytime, given a really good sky. The overall appearance might be similar to descriptions of the brilliant Comet Skjellerup-Maristan y in 1927, when it was viewed in daylight not far from the Sun.

Immediately following sunset, the comet's head would likely appear a dramatic yellowish hue, due to the strong emission lines of sodium, as would the beginnings of the tail, this often being seen in conjunction with major comets at small q. The intense, almost straight, combined ion-dust tail might be traced 10 or more degrees upwards in the bright sky, with both components becoming much longer as twilight deepens. I would speculate that the overall impression at that time might be somewhat similar to that displayed after sunset by the Great Daylight Comet of 1910, given that the tail projection circumstances happen to be so favorable.

HOWEVER, any such potential grand display is, at the moment, pure speculation. The next few days of twilight observations are likely to tell the true story. And remember, even if C/2006 P1 does develop dramatically, its display is likely to be rather short-lived, both because of the brief duration of the forward-scattering event and the fact that the comet swiftly moves away from the Earth after mid January. So...pray for universally clear weather in mid January!

JBortle

END QUOTE

Bill

Posted by: edstrick Jan 7 2007, 09:55 AM

In 1976 or 7, Comet West rounded the sun as a barely news-covered object with a rather small perihelion, and the nucleus split off several chunks, resulting in a massive dust release and spectacular morning apparition as it pulled away from the sun with a quite favorible viewing geometry. It's the most spectacular comet I ever saw, starting with Comet Bennet in about 1970.

Posted by: Stu Jan 7 2007, 10:28 AM

Four great comet memories for me...

Standing in a lay-by (that's a small, off-road car parking area, for our non-UK members! ) with my long-suffering but ever-patient and understanding mum, staring at Comet IRAS-Araki-Alcock on a chilly night in 1983. It looked like a round chalk smudge in the Little Dipper, very obvious to the naked eye and like a blue-grey puffball in my shaking binoculars. My first "real comet"!

Then 1985, Halley's Comet returned. I "found" it on Bonfire Night, (Nov 5th for our US friends), barely-there in binocs in a sky muddied and blurred with the smoke of all the bonfires burning in and fireworks exploding above my town. A shiver literally ran up my spine - it was there, The Comet, Halley's Comet, the one I'd read about for soooooo long - before I shouted "Yes!!" at the sky, causing a nearby dog walker to ask if I was alright... A month or so later I was asked, by her daughter, to go and show the comet to a very old lady who had seen it in 1910. I went up to the house, set up my trusty 3" Tasco reflector, and swung it around to the comet and asked the old lady to come over and look. To be honest, she knew nothing about astronomy, and to save time I could have just aimed at a star and defocussed it to make it look like a comet, but I didn't... and when she peered into the eyepiece a huge smile broke over her face and she started laughing... I asked why, and she said that her father had shown her the comet in 1910, as a girl, and had told her she's never see it again. "You just proved the old b*****d wrong for me, thank you!" she said. Quite a moment!

Then, I guess, it would have to be seeing Comet Hyakutake on a blustery night in 1996, standing in the shadow of one of the Lake District's beautiful fells at midnight. The sky was mostly cloudy, just the odd gap floating across here and there... in one of those gaps my observing partner and I saw a "beam" of light. Just a vapour trail, we agreed, as it was surely a) too bright, and too far away from the predicted location of the comet's head to be anything to do with Hyakutake... right..? Wrong. Soon after the clouds swept away and there was the comet, painted across the sky like a grey-green lighthouse beam, ridiculously, and I mean ridiculously long. Sweeping it with binoculars we saw brighter areas, clumps, filigree streamers and lines... just beautiful... never forget that...

Finally, standing in the centre of the ancient Castlerigg Stone Circle, on a hillside above Keswick, watching Comet Hale-Bopp rising up from behind another fell, tails first... it looked like someone was shining torches into the sky from behind the fell, the tails were so pronounced, then the head cleared the felltop and standing there, leaning against one of the cold, ancient stones, watching a Great Comet rising, no words were necessary. Beautiful.

McNaught has a lot to live up to...

Posted by: remcook Jan 7 2007, 12:02 PM

Did anyone put any pictures on the web of the comet yet? They must have, but I didn't find any recent ones with a quick search...

edit - d'oh!
http://www.phys.ncku.edu.tw/~astrolab/mirrors/apod_e/ap070105.html


I clearly remember Hale-Bopp, but not Hyakutake... I was a bit young then and not greatly into astronomy.

Posted by: Stu Jan 7 2007, 12:07 PM

QUOTE (remcook @ Jan 7 2007, 12:02 PM)

Posted by: Bob Shaw Jan 7 2007, 02:55 PM

Apart from the forthcoming SOHO views, does anyone know of any other spacecraft which are slated to observe Comet McNaught? Obviously, few will be able to look at it while it's turning past the Sun!


Bob Shaw

Posted by: tasp Jan 7 2007, 03:03 PM

I recall being mesmerized by Comet Bennet as a young teenager. Unusual for me to have seen a comet in the east, as my boyhood home was built on the west slope of a rather large hill. My Bennet recollection was made possible by a timely trip across Kansas from north to south on our way to visit relatives in Oklahoma.

The comet was the highlight of the trip.


Bennet remains for me, my 'standard' comet.

Posted by: edstrick Jan 8 2007, 12:24 PM

http://spaceweather.com/ has a link to a pagefull of recent images of the bright comet in BRIGHT twilight. I'm trying to see it before I go to bed this morning.

Posted by: ynyralmaen Jan 8 2007, 12:36 PM

QUOTE (Bob Shaw @ Jan 7 2007, 03:55 PM)

Posted by: ups Jan 8 2007, 12:42 PM

Let's hope Comet McNaught starts flaring up soon...
______

Michael Jager and Gerald Rhemann photographed comet C/2006 P1 (McNaught) from Austria in twilight 45 minutes before sunrise on Jan. 3. Rhemann told SPACE.com they used 7x50 binoculars to find the comet. They estimate that today (Jan. 5) it shone at magnitude +1 and they expect to see it with the naked eye next week. Image used with permission.

http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=070105_mcnaught_pic_02.jpg&cap=Michael+Jager+and+Gerald+Rhemann+photographed+comet+C%2F2006+P1+%28McNaught%29+from+Austria+in+twilight+45+minutes+before+sunrise+on+Jan.+3.+Rhemann+told+SPCE.com+they+used+7x50+binoculars+to+find+the+comet.+They+estimate+that+today+%28Jan.+5%29+it+shone+at+magnitude+%2B1+and+they+expect+to+see+it+with+the+naked+eye+next+week.+Image+used+with+permssion.

Posted by: djellison Jan 8 2007, 01:05 PM

merged the two topics - we were doubling up.

Complete cloud for the past couple of days here - not a hope in hell of seing the thing.

Doug

Posted by: ugordan Jan 8 2007, 02:07 PM

This is probably lack of sleep affecting my mental abilities, but how can the comet be visible at dawn AND at twilight at the same time? Wouldn't that suggest a north-south position w/respect to the Sun -- in wich case it would set/rise at the same time as the Sun? Well, more or less...

EDIT: Aaaargh... nevermind, I got it. Has to do with Earth's tilt so northern objects rise earlier and set later from the northern hemisphere, right?

Posted by: akuo Jan 8 2007, 02:34 PM

Yes, the comet is currently about 10 degrees almost directly north of the sun, which means far enough north (like in northern Finland), you could observe the comet all DAY, since the sun doesn't rise over the horizon at all. This would require almost totally clear horizon and good weather, and the weather hasn't been acting nicely at least for me: almost constant rain for the last week or so. I guess I'll miss the chance to see another naked eye comet .

The comet is closing in on sun fast and in a few days it'll be off to the southern declinations and forever gone to us northeners. People of the southern hemisphere might get a good show though.

Posted by: ugordan Jan 8 2007, 02:41 PM

If it makes you feel any better, I've got clouds for the past few days as well. The last comet I actually saw was Hale-Bopp!

Posted by: Mongo Jan 8 2007, 03:26 PM

It's the same story here -- nothing but 100 percent cloud forecast for the next week to ten days. I also looked at the location of my parents (2000 km away) and they are facing almost the same forecast (with the exception of a possibility of partly clear skys on Thursday). Frustrating is the word, all right.

Bill

Posted by: Sunspot Jan 8 2007, 04:24 PM

QUOTE (ugordan @ Jan 8 2007, 02:41 PM)

Posted by: djellison Jan 8 2007, 04:36 PM

There is a mutual exclusivity between transient astronomical phenomenon and the British climate - I'm sure of it.

Doug

Posted by: Myran Jan 8 2007, 04:44 PM

Posted by: dvandorn Jan 8 2007, 07:29 PM

The first comet I tried to see was Ikeya-Seki in 1968 (I believe it was). It flew too close to the Sun and disintegrated, if I recall correctly, and so the impressive display we were supposed to see in the northern hemisphere never materialized. (I think I have this right -- I was only 12 at the time, and all I recall really clearly is that I was never able to see the thing, which was a big disappointment at the time.)

The first comet I remember actually seeing was Bennett in 1970. I had received a small telescope (3" reflector) for Christmas, and so when Bennett became clear and naked-eye visible in the early spring, I was out in my back yard (at ridiculous-o'clock-in-the-morrning, especially for a 14-year-old) with my 'scope, looking at the comet. I never saw a nucleus; I think all my 'scope was able to resolve was the coma. The tail was well defined, though, and some very nice knots and streamers were visible, if fainter than I would have expected.

As for more recent comets, Hyakutake wasn't nearly as impressive to me as Hale-Bopp was. Perhaps we in the northern hemisphere didn't get a really good viewing angle on Hyakutake, but all I ever recall seeing of it was a fuzzy blotch in the sky with a tail that you had to look away from it to see -- it faded to invisibility if you looked directly at it.

Hale-Bopp, however... that was the most impressive comet I've ever seen. Its tail was also not as bright and noticeable as I would have expected -- after a certain distance from the nucleus, it was best seen out of the corner of one's eye. But in very clear and dark skies, it was an amazing site.

Especially from the air... you see, in April of '97 I went to England on business, and as we flew through the (very short) night along the Great Circle route up north of the Arctic Circle, I saw the most impressive sight I can ever recall: green curtains of auroral displays draping the horizon, with Hale-Bopp hovering barely five degrees above the horizon, its dust tail forming a great sweeping filament that seemed to flow up and out of the auroras, its ion tail flashing brightest of all, bluish against the green of the auroras.

It was a view worth the price of the trip...

-the other Doug

Posted by: Bob Shaw Jan 8 2007, 10:25 PM

QUOTE (djellison @ Jan 8 2007, 04:36 PM)

Posted by: climber Jan 8 2007, 10:35 PM

QUOTE (djellison @ Jan 8 2007, 05:36 PM)

Posted by: Bob Shaw Jan 8 2007, 10:40 PM

QUOTE (climber @ Jan 8 2007, 10:35 PM)

Don't complain please, I'm the one that has too. I'm in Hawaii (Kawaii) right now and it's raining... and will not stop for another 3 days

Posted by: volcanopele Jan 8 2007, 10:40 PM

Not a cloud in the sky here I'll have to take a look tonight (no way I'm getting up that early tomorrow morning...)

Posted by: Stu Jan 8 2007, 10:56 PM

Much more rain here in Kendal and I'm going to start building a big boat and rounding up pairs of animals...

Posted by: Bob Shaw Jan 8 2007, 11:00 PM

QUOTE (Stu @ Jan 8 2007, 10:56 PM)

Much more rain here in Kendal and I'm going to start building a big boat and rounding up pairs of animals...

Posted by: climber Jan 9 2007, 01:51 AM

QUOTE (Stu @ Jan 8 2007, 11:56 PM)

Much more rain here in Kendal and I'm going to start building a big boat and rounding up pairs of animals...

Posted by: nprev Jan 9 2007, 03:09 AM

Man, here in Southern California I've got clear skies and an unobstructed view of the western horizon, and I STILL can't see it due to the <clink> smog/haze and light pollution!!!

Posted by: edstrick Jan 9 2007, 08:43 AM

In the spaceweather.com gallery, the furthest south it's been spotted seems to be San Francisco. the lower the lattitude, the flatter the line from sun to comet is to the horizon. It really needs to stick up at a high angle as it does in Scandanavia.

Posted by: Bjorn Jonsson Jan 9 2007, 10:31 AM

I saw the comet this morning and it is *very* bright, the sky wasn't very dark but despite this the tail was fairly long and easily visible and the nucleus very bright. It's probably brighter than Hale-Bopp ever was although this is difficult to estimate since the viewing geometry is very different, McNaught was low in the sky when I saw it, buildings and streetlights nearby and my memory isn't perfect.

Posted by: ugordan Jan 9 2007, 03:01 PM

They say it topped Hale-Bopp's http://cfa-www.harvard.edu/icq/brightest.html. Looks like folks in the southern hemisphere might be up for a spectacular show after perihelion. Meanwhile, still %^@!& cloudy here with a hole in the clouds here and there, but never in the right place.

Posted by: Myran Jan 9 2007, 05:49 PM

I've seen it finally, I had to rescedule my sleep but now I bagged this one!
Its a nice one. And I think edstrick is right, for a second time we up in the north got one advantage. Halley was completely hopeless for us this time around (Hally of the year 837 are said to have been spectacular thought and comparable to Hyakutake which covered 120 degrees in the sky and a naked eye head 2 degrees wide to mention some fact), then after that treat Hale Bopp didnt get me exited at all.
Yet I concur with ugordan and Bjorn Jonsson MacNaught is a very bight one. To bad the best part will be on the souther hemisphere like with comet West that I never got a good look at. So far I can compare McNaught with Kohoutek - if memory serves me right.

Posted by: Sunspot Jan 9 2007, 05:59 PM

Last night I had a dream I saw the comet

Posted by: PhilCo126 Jan 9 2007, 06:21 PM

http://cometography.com/lcomets/2006p1.html

Posted by: ugordan Jan 9 2007, 10:01 PM

Correct me if I'm wrong but as Jan 12 approaches, conditions for viewing will become rapidly unfavorable? That's as little as two days. Those in the north who got to see it, saw it. Those who haven't, won't...

Posted by: Stu Jan 9 2007, 10:13 PM

You're right, and I reckon - from using STARRY NIGHT - I have two more days to see it, then that's it, I'll have to watch it cross the SOHO field of view and then grit my teeth as I read reports from the s hemisphere. Forecast is promising for here for tomorrow sunset and Thursday dawn, so fingers crossed...

Posted by: ugordan Jan 9 2007, 10:43 PM

Magnitude -2 now!
Maybe we should try finding it in broad daylight?

Posted by: ynyralmaen Jan 9 2007, 11:25 PM

QUOTE (ugordan @ Jan 9 2007, 11:43 PM)

Maybe we should try finding it in broad daylight?

Posted by: ljk4-1 Jan 10 2007, 01:51 AM

Comet McNaught 2006 P/1 Finder Charts from Skymaps.com

Comet McNaught is continuing to brighten and promises to be a bright comet indeed, most likely visible to the unaided eye. In the early part of January, Northern Hemisphere observers can view the comet very low in the western sky just after sunset. The comet will get progressively closer to the Sun each day eventually disappearing from view around 13 January. From mid-January onwards sky watchers in the Southern Hemisphere will be able to catch their first views of the comet just after sunset as it emerges from its journey past the Sun.

The following finder charts for the Northern and Southern Hemispheres show the location of Comet McNaught at sunset relative to Venus and the western horizon. Start looking for Comet McNaught a few minutes after at sunset by using brilliant Venus as a guide. You will require a location with a clear view of the western horizon. Even though the comet may become bright enough to be seen with the unaided eye, a good pair of binoculars or a telescope will reveal much more detail.

http://www.skymaps.com/comets/index.html

Posted by: Sunspot Jan 10 2007, 11:08 AM

Weird.. I had another Comet dream last night. And the sun has finally come out, might be clear later this afternoon and finally get to see it.

Posted by: remcook Jan 10 2007, 11:54 AM

there's some sun here now finally. I'll try and have a look at sunset.

Posted by: ugordan Jan 10 2007, 12:27 PM

What exactly is the comet's angular separation from the sun today? I haven't seen it mentioned anywhere. That would help a bit in trying to locate the thing in the bright sunset sky. The sky is almost totally clear here as well, hope it holds up for 4 more hours!

Posted by: karolp Jan 10 2007, 12:27 PM

And here is a nice ANIMATION of the naughty naught:

http://www.astrostudio.at/common/video/movieMcNaught.php

Posted by: Stu Jan 10 2007, 12:43 PM

What's the funniest thing you've ever seen? Peter Kay's Blackpool Tower show? Del Boy falling through that open bar on "Only Fools"? Seinfeld? Monty Python and The Holy Grail? The Christmas episode of "My Family"? (only joking!) Well, I have something to beat them all...

In today's DAILY MAIL, astrologer Jonathan "Show me a bandwagon and I'll jump on it" Cainer has a HUGE feature explaining how Comet McNaught is going to change the world, and is "a portent". Couple of quotes for you... I thought we left this kind of rubbish behind decades ago, but apparently not...

"It may prove auspicious for the Royal Family. Comets usually bode badly for powerful people who are trying to prevent change. World leaders, major religious figures and icons of the establishment can all expect to have their worlds dramatically altered soon".

"It looks like a spaceship standing still in the sky".

And, of Comet Hale-Bopp, and this made me choke on my Rice Krispies:

"It hung in the heavens night after night, eerily portending the death of Diana, Princess of Wales".

He should do a turn on the stage at the Phoenix Club on "Phoenix Nights", seriously.

Posted by: karolp Jan 10 2007, 01:14 PM

For comparison: around the time of Discovery mission Polish tabloids used to run a daily feature on how the lives of astronauts are being put on risk again and that they are probably not going to make it this time while in reality there was only some minor non-hazardous technical glitch, I just wonder what they will do with McNaught provided they give it some coverage at all...

Posted by: Ames Jan 10 2007, 04:36 PM

Here in the UK the weather has cleared a little and the sun has set.

Go outside and see if you can spot it low down in the west, to the right of venus.

http://www.spaceweather.com/images2007/08jan07/skymap_north.gif

Nick

Posted by: remcook Jan 10 2007, 04:49 PM

woohoo seen it

Posted by: Ames Jan 10 2007, 05:10 PM

Got 20 colleagues jostling up against a window in the office.

Spectacular!

It’s my birthday too, best present ever – Hurrah!


Nick

Posted by: djellison Jan 10 2007, 05:11 PM

Had a damn good look - but there are too many buildings, streetlights, and , well, too much crap for me to see it here. Not a chance sadly.

Doug

Posted by: remcook Jan 10 2007, 05:21 PM

it was quite faint for quite a while. We had a group on the roof of the department.

Posted by: Stu Jan 10 2007, 05:52 PM

Sometimes - just sometimes - I absolutely HATE this hobby. Some nights are just cursed, doomed from the start, like mine was tonight.

Clear sky all afternoon, and I made it up to my observing site at Kendal Castle by 3.50, with the sky a peacock blue and scattered here and there with clouds, but the SW sky almost cloud free. Started to set up my scope... tripod out... tube on... eyepeices - no eyepieces! Left them at my flat after cleaning them. So, spotting someone nearby with a tripod and camera I asked him if he was staying for a while, and when he said he was I asked if he would watch my gear while I ran home for the eyepieces. He said yes, no prob, so I ran back down the hill like the b****y Duke of York, grabbed the eyepieces, ran back again... so far so good, sky still clear...

Found the comet! Yaaay! Much brighter than the last time I saw it, tail well developed too...snapped a few pics with my digital, then started to set up the photo tripod borrowed from my girlfriend to take some pics with an SLR... got the tripod set up... rapid release head missing, so no way of mounting the camera...

Meanwhile, the cloud has started to boil up from the horizon, just as some ******* down in town starts to burn car tyres, sending great clouds of blue-white smoke up to and over me...

Managed to get a couple of pics of the comet thru the eyepiece, lovely star-like head and split tail - then it vanished, swallowed up by cloud, and looking up from the eyepeice I saw a mountain of cloud covering the sky from S to W and reaching up to almost 45 degrees altitude. It took more than 40 mins to clear, while the rest of the sky - and I mean the whole of the rest of the sky - was perfectly, perfectly clear...

When the cloud finally moved away from the comet it was beautiful, shining gold, with a tail several degrees long, but there was no time to take any pictures because literally 2 mins later it slid behind the cloud that was hugging the horizon, and was lost, this time with no hope of recovery. All that was left, for a few moments, was a hint of a golden tail, jabbing upfrom behind the cloud like a distant WW2 searchlight, then that too was gone.

The forecast for the rest of the week is so dreadful that I know I won't see the comet again, that's it. Tonight promised so much and I feel like it was ripped away by the sky, and that it laughed at me as it did so, you know?

Maybe next time.

Hope some of you had great views!

Posted by: Sunspot Jan 10 2007, 06:44 PM

An advantage of living on the Fens I suppose... very flat

Posted by: akuo Jan 10 2007, 06:55 PM

Caught the comet at last! Saw it 15 minutes after sunset -- the sky was so bright, but the comet was still visible naked eye. It is amazingly bright to be visible with almost blue sky. After that the clouds came and unfortunately I didn't see it during darker sky.

Posted by: Tesheiner Jan 10 2007, 09:07 PM

Oh the f****** weather!

I tried to find it on sunday, no chance. Then I said to myself: "No problem at all; it'll be brighter during next week".

And we have cloudy (haze) sky since Monday and the forecast is the same.

Posted by: djellison Jan 10 2007, 09:33 PM

The Fens...wow - not far from here really.


Doug

Posted by: Bob Shaw Jan 10 2007, 09:46 PM

I've been looking in the morning and the evening for the last few days, but have yet to see a thing - not even Venus!

Bah!

I blame the BBC.



Bob Shaw

Posted by: Stu Jan 10 2007, 11:23 PM

Best I managed tonight...

Posted by: tasp Jan 10 2007, 11:45 PM

I am in western Iowa north of Omaha Nebraska, and have been watching the comet naked eye for 10 minutes. (5:30 to 5:40 PM CST)

I am indoors now, and the comet is just barely visible through the 2nd floor window facing west.

Posted by: tasp Jan 10 2007, 11:50 PM

Still visible from indoors at 5:47 PM CST.

Outdoor view naked eye tail appears 3/4 of a degree long. Indoors, maybe 1/4 degree of tail visible.

'Classic' comet appearance, bright star like head, and fanning tail apparent. Just very tiny though, nowhere near the size of Bennet.

Posted by: tasp Jan 10 2007, 11:52 PM

Comet still visible from indoors, just 2 or 3 degrees above the horizon.

Earlier, could not distinguish comet from several jet contrails, but quite obvious now.

Posted by: nprev Jan 11 2007, 01:28 AM

...clouded out again in Southern California. In fact, they're calling for not only rain but possibly SNOW at elevations above 1000 ft. tomorrow evening! What are the odds of that happening here during the apparition of a major comet???

(sigh)...please take good pics, guys.

Posted by: ugordan Jan 11 2007, 08:16 AM

After two failed attempts yesterday, I gave up on trying to see it. I didn't get practically a single cloud all day yesterday EXCEPT before sunrise AND during sunset. In the morning I had a few thin breaks in the clouds in the east, but it was hopeless. During sunset, it was actually not that bad except several layers of high clouds really gave off a bright red glare for a while after sunset, drowning out anything remotely faint. I just couldn't locate the thing -- had no idea just how big an object I'm actually looking for or what its angular distance from the sun was.
I did get to see Venus, though (yay...)

Posted by: AndyG Jan 11 2007, 09:55 AM

QUOTE (Bob Shaw @ Jan 10 2007, 09:46 PM)

Posted by: djellison Jan 11 2007, 10:24 AM

http://neo.jpl.nasa.gov/cgi-bin/db_shm?rec=902773

Cool trajectory diagram showing why it's being so elusive.

Doug

Posted by: SkyeLab Jan 11 2007, 12:37 PM

The BBC have posted some pics of the comet sent in by viewers:

http://news.bbc.co.uk/1/hi/in_pictures/6251663.stm

Enjoy.........

Brian

Posted by: ugordan Jan 11 2007, 12:41 PM

QUOTE (SkyeLab @ Jan 11 2007, 01:37 PM)

Posted by: Bob Shaw Jan 11 2007, 01:04 PM

QUOTE (AndyG @ Jan 11 2007, 09:55 AM)

Posted by: odave Jan 11 2007, 02:01 PM

I had a shot at seeing it last night - there was a nice hole in the clouds around Venus but it didn't extend far enough I'm going to be socked in for the next few days, so I think that's it for me.

For those in North America who don't know about them, http://cleardarksky.com/csk/ are a great tool for observing session planning. He wrote some scripts and an interface to present data from the Canadian Meteorological Center that forecasts hourly cloud cover, transparency, seeing, and other items for the next two days in a specified area (~15km radius). Here's the http://cleardarksky.com/c/NCOMIkey.html?1, and as you can see tonight and probably tomorrow night's a wash.

Overall I've found the forecasts to be pretty accurate. The only downside is that they've made me very picky about the sky conditions, or at least given me an excuse not to drag my lazy butt out when it's cold

Posted by: Holder of the Two Leashes Jan 11 2007, 04:07 PM

I observed the comet Wednesday evening from downtown Tulsa, Oklahoma. I had tried and failed the evening before (both days had remarkably clear skies), but came better equiped the second try. It was visible from 17:50 to 18:15 Central Standard Time.

Once spotted, it was an unmistakable point source with the naked eye. Through 10X50 binoculars, it was amazing. Fat, bright coma with a narrow fan tail extending about half a degree.

Very pleased to get that look. The weather here since and for the immediate future has put an end to the comet show.

Posted by: SkyeLab Jan 11 2007, 04:29 PM

Only a few more hours until SOHO gets a peak at it.

Nice write up here:

http://sohowww.nascom.nasa.gov/hotshots/

Cheers

Brian

Posted by: ugordan Jan 11 2007, 04:32 PM

I got to see it just now on my way home from work. I noticed the sky was fairly clear so I decided to give it one last try. For those of you who are still waiting for sunset and are having trouble locating it:
15 minutes or so after sunset, locate Venus and draw a horizontal line from about 2/3 of its height in the sky. If you're in the mid-latitudes, draw a line at 45 degrees from the point the sun set towards the north. The intersection of the two imaginary lines is the general area you should scan to find it.

The conditions weren't very favorable for viewing and seeing it was a tribute to how bright it actually is. The western sky had some transparent high clouds and some 15 minutes later I noticed the atmosphere was pretty hazy as well as sun rays were tracing a light glow in the air. This, along with the comet's low position, made the contrast rather low as the brightest ray happened to pass over the comet. Nevertheless, through the clouds it did appear to be a star-like point at first sight, with a slight nebulosity to it (it helps to know you're looking at a comet). The tail is pretty small, about 1 degree tops from what I could see in the glowing twilight. It was setting rapidly so conditions weren't getting much better. I wish I had a pair of binoculars, with the naked eye it only appeared to have a slightly curved coma.

Posted by: Sunspot Jan 11 2007, 05:35 PM

Managed to spot it too this evening, although the sky was a little hazy.

Posted by: ustrax Jan 11 2007, 05:57 PM

http://sohowww.nascom.nasa.gov/localinfo/fleck.html from ESA and SOHO's Project Scientist was kind enough to answer questions about the comet's observations.

EDITED: If you have any, just shoot them here or send me an e-mail or message untill tomorrow's 1200GMT.

Posted by: Stu Jan 11 2007, 06:16 PM

Sometimes - just sometimes - I LOVE this hobby.

Tonight I notched up my third, and most unexpected and possibly most rewarding too, sighting of Comet McNaught. Like the comet, it came from nowhere. I was shopping in town, and coming out of WH Smiths looked up and saw the sky that had previously been a flat sheet of unbroken grey was now tattered and ripped everywhere, with great, tantalising gaps of bright blue showing through. What?!?!? That wasn't supposed to happen! Within half an hour I was setting off up to the Castle again, this time travelling light - just my binocs, digital camera and SLR in my quick-gran rucksack I keep by the door. It's been blowing a gale all day here in Kendal, with sheets of icy rain slapping across the town on and off all day, and as I walked up to the castle again the rain returned and the open patches of clear sky started to close up again, but I kept going, putting faith in the gut feeling I had that after last night's disappointment perhaps, just perhaps, the Universe was going to take pity on me and give me another glimpse of the comet.

I wasn't wrong. Reaching the shelter of the inside of the castle ruins I wedged myself into a corner of one of the ruined towers, steadying myself against the buffetting wind on the high hilltop, and just waited. And, yes... the rain eventually stopped, the sky ripped open again and after sweeping the wounded area above the SW horizon I saw the comet again, even brighter than last night, silvery white against the bruised orange blue sky. Yes!!

For the next half hour the comet and I played hide and seek. It kept slipping behind the drifting clouds, only for me to find it again. At one point, and I'll never forget this, the rain was stinging me from the right, pelting in from the north, while I watched the comet through my binoculars. I was actually observing the comet in the rain... how crazy is that?!?!

There was no chance of taking any pictures tonight: the wind was too strong, slapping me like a hand every time I dared emerge from my little stone shelter, so all I could do was watch the comet through my binocs, grudgingly stopping now and again to wipe rain off the lenses. Eventually the comet won the game of hide and seek, it found a place to hide behind a big, grey wedge of cloud and I just couldn't find it. But to be honest, I didn't care, not like I did last night. Last night I was sure I'd had my last view of the comet, but tonight I proved myself wrong, and it felt pretty good!

Anyway, that was it for tonight, so I packed my binocs away and said goodbye to the comet, surrendering it to the southern sky, cos I'm sure I won't see it a fourth time, and set off back for home.

Before tonight I was sure that for me, Comet McNaught would always be my "nearly comet", the one I nearly saw at its best. After tonight, it'll always be The Comet I Saw In The Rain. Which is pretty cool.

Hope everyone out there's getting some great views too!

Posted by: Tesheiner Jan 11 2007, 08:14 PM

Got it!

Finally, after many cloudy days, we had a clean evening sky today. Last chance, I said to myself.
I have a clear view on my backyard to a flat field covering from S to W, perfect to this ocasion (the only concern is/was the weather), so me and the kids went outside at about 18:00 (17:00 UTC) with my camera and the binoculars, but the sky was still too bright to see anything except for the jet contrails; back inside.
The second attempt was at 18:20 (or so) and Venus was easily found to the SW but nothing about the comet. I was a bit disappointed but took the last opportunity right after 18:30 and there it was! Visible with the naked eye and located two or three fingers above the horizon through the red/orange contamination cloud (!) covering the Madrid area.

Beautiful sight with the binoculars. The nucleous was very bright and the tail looked like "mixed" with the haze in the foreground. Another remarkable thing was it's orange look, quite different from the usual "milky look" of the comets I've previously seen.

I did take some photos of it but no luck. Either my camera is not sensitive enough or my arm is not as stable as a tripod. Bet for the second option.

Posted by: remcook Jan 11 2007, 09:30 PM

a big cloud on the horizon today and lots of cloud predicted for the nect few days. Till when will it visible?

Posted by: djellison Jan 11 2007, 09:43 PM

Well - from tomorrow it's visible in SOHO images - that's probably all the clue you need. Northern Hemispheriques are probably out of luck...perhaps tomorrow AM, and MAAAyyyybe tomorrow night, but I doubt it.

Doug

Posted by: hendric Jan 11 2007, 10:53 PM

Hey, anyone ask Steve if one of the MER's would be willing to take a shot at it as it leaves the inner Solar System? That would be totally awesome.

Posted by: Sunspot Jan 11 2007, 11:04 PM

This was the view here 20 minutes after sunset, the sky was a bit hazy so noting like what it looked like yesterday . Also it was SOOO windy, most of the images are a bit blurred from the camera shaking on the tripod.

Posted by: Toma B Jan 11 2007, 11:08 PM

QUOTE (djellison @ Jan 12 2007, 12:43 AM)

Posted by: NMRguy Jan 11 2007, 11:21 PM

Having moved to Amsterdam last year, I kind of wrote off time-sensitive planetary observations. Cloud cover always coincides with comets and meteor showers. This winter has been characteristically dreary, and today was exceptionally bad. Rain, clouds, and wind advisories! Baah.

Extraordinarily enough, the clouds vanished right before sunset. I couldn’t believe my luck! So at 5:30pm, I climbed up to the 14th floor and looked southwest. I found Venus, and sure enough off to the right and not quite half way down was a beautiful fuzzy star. The red glow of the sunset was still prominent near the horizon, correspondingly reducing the apparent brightness of the comet. That I could see anything at all is a testament to the remarkable strength of the comet output.

Overall, the tail was very visible and appeared to be at least two full moon diameters. I am sure that additional darkening would have improved viewing further. But just as quickly as the clouds had disappeared, they returned and consumed Comet McNaught. I count myself among the lucky.

Although McNaught is a very bright comet, I would hesitate from calling it a “Great Comet”. Its orbit precludes it from being widely visible to the public—at least in the Northern Hemisphere. The main show on this side of the sun has always been low in the sky near the horizon. Those of you in the Southern Hemisphere should keep your fingers crossed for a brighter return. And although I do have fonder memories of Hale-Bopp and especially Hyakutake, I would rate this as a very pleasing comet viewing experience.

Posted by: Toma B Jan 11 2007, 11:39 PM

QUOTE (NMRguy @ Jan 12 2007, 02:21 AM)

Posted by: Roby72 Jan 11 2007, 11:55 PM

Hello all,

Yesterday I have some luck with the clouds here in Austria. McNaught is a nice and bright comet, but currently far away from earth. I remember comet Hyakutakes show in March 1996 with only 15mio km distance. Its tail span almost 50 degrees...

Here you could find my images:

http://www.pbase.com/astrophoto/mc_naught_2007

Robert

Posted by: jamescanvin Jan 11 2007, 11:59 PM

B)-->

QUOTE(Toma B @ Jan 12 2007, 10:39 AM)

Posted by: Bob Shaw Jan 12 2007, 12:17 AM

QUOTE (Roby72 @ Jan 11 2007, 11:55 PM)

Hello all,

Yesterday I have some luck with the clouds here in Austria. McNaught is a nice and bright comet, but currently far away from earth. I remember comet Hyakutakes show in March 1996 with only 15mio km distance. Its tail span almost 50 degrees...


Robert

Robert:

Great images!


Bob Shaw

Posted by: jamescanvin Jan 12 2007, 05:37 AM

Looks like McNaught is just moving into SOHOs view now.

Not long for us southern hemisphere folk now.

James

Posted by: Tesheiner Jan 12 2007, 09:08 AM

QUOTE (Toma B @ Jan 12 2007, 12:39 AM)

Hmmmm.....
Lets see...does anybody here live in southern hemisphere...
Tesheiner ??? / Brazil

Not currently. I was born in Brazil (at Porto Alegre) but moved to Spain with 21 years old.
I saw McNaught yesterday evening and will try again today now that I know exactly where to look at.

Living in the southern hemisphere up to 1986 I had the chance to see the Halley.

Posted by: pch Jan 12 2007, 09:04 PM

Just get chance with the cloud today in Geneva, Switzerland. I can take this image ten minutes before sunset. Using a 300mm objective this is the first time I shoot a comet at 1/1000 exposure!

This comet is indeed very bright, it compare well with the nearby Venus.
Good luck for southern observer next week!

Posted by: Bob Shaw Jan 12 2007, 10:06 PM

QUOTE (pch @ Jan 12 2007, 09:04 PM)

Just get chance with the cloud today in Geneva, Switzerland. I can take this image ten minutes before sunset. Using a 300mm objective this is the first time I shoot a comet at 1/1000 exposure!

This comet is indeed very bright, it compare well with the nearby Venus.
Good luck for southern observer next week!

Wow. That thing is bright... ...1/1000 sec is a helluva short exposure!

...and I missed it.


Bob Shaw

Posted by: climber Jan 13 2007, 08:14 PM

QUOTE (Tman @ Jan 13 2007, 08:55 PM)

Altogether a perfect comet watching during a wonderful sunset - and no kidding, there were even two women who played the alpenhorn during the whole time (hence I have to say "a perfect swiss comet watching").

Ouah, that's should have been dramatic! I love alpenhorn...

Posted by: ugordan Jan 14 2007, 01:14 AM

CODE

peak
  m1         Comet
----     ----------------------
(-7)     C/1965 S1 (Ikeya-Seki)
(-4.5)   C/2006 P1 (McNaught)
(-4)     C/1947 X1 (Southern comet)
-3.0     C/1975 V1 (West)
-0.8     C/1995 O1 (Hale-Bopp)

This calls for a daytime observation attempt!

Posted by: MizarKey Jan 14 2007, 05:21 AM

QUOTE (nprev @ Jan 13 2007, 05:30 PM)

Here's a link to the latest SOHO LASCO image: http://sohowww.nascom.nasa.gov/data/realtime/c3/512/

If you go to the soho site and run the latest c3 animation, there's a 'ghost' comet image mirrored from the opposite corner of the frame. It's cool, you can see the tail pointing away from the sun better than the actual comet. That's one bright comet to be causing such a strong reflection in the optics.

Posted by: ugordan Jan 14 2007, 10:54 AM

QUOTE (MizarKey @ Jan 14 2007, 06:21 AM)

If you go to the soho site and run the latest c3 animation, there's a 'ghost' comet image mirrored from the opposite corner of the frame. It's cool, you can see the tail pointing away from the sun better than the actual comet.

I doubt the optics produce a clear double image of the comet, looks more diffuse stray light to me. Another interesting point in the movie is about halfway through the latest one you can see a change in camera settings of some sort. The horizontal bleed on the comet and Mercury shortens and the noise in the frame increases. My guess is they lowered the exposure to alleviate the sheer brightness of the thing.

Posted by: jamescanvin Jan 14 2007, 09:37 PM

First attempt here in Sydney last night. We had had a cloudless day, without as much haze as much of the last week. But then what happened - cloud bubbled up as sunset approached Margaret and I even felt a spot or two of rain at one point. Of course I took this as a good omen remembering Stu's experience. But unfortunately we couldn't even see the sun during its last 30 minutes so we had no chance of seeing McNaught, it setting just 23 minutes after the sun. Had a few looks for it during daylight, but I don't think I've worked out it's position closely enough yet. Did get some nice views of Sydney as the light faded, so not a wasted trip.

(Note Venus at the far left)

Attempt two tonight...

James

Posted by: jamescanvin Jan 15 2007, 12:31 AM

QUOTE (djellison @ Jan 15 2007, 10:51 AM)

Ooo - look at me - trying to take pictures of a comet but I accidentally took a photo of the Sydney Harbour Bridge instead.....

Ahh, if I was really showing off I'd have moved a bit so that the Opera House wasn't behind that bush to the left of the bridge.

J

Posted by: MizarKey Jan 15 2007, 09:30 PM

QUOTE (djellison @ Jan 11 2007, 02:24 AM)

http://neo.jpl.nasa.gov/cgi-bin/db_shm?rec=902773

Cool trajectory diagram showing why it's being so elusive.

Doug

Looks like McNaught will pass relatively close to Mars around Feb. 17th~18th, I doubt it will be as bright in the Martian sky by then though. I wonder if MEX or HiRise have any kind of chance of spotting it? Probably better with Hubble?

Never mind, after fiddling with the controls I see that the comet's passage through the solar system doesn't bring it anywhere near any of the planets...even when crossing the plane inside Mercury's orbit Mercury was on the opposite side of the sun from it. Doh!

Posted by: djellison Jan 15 2007, 09:33 PM

What we need with data like THAT
http://cfa-www.harvard.edu/icq/CometMags.html#2006P1

Is a graph.

Mag on the Y scale - d.o.y. on the X.

 

Posted by: jamescanvin Jan 16 2007, 05:15 AM

QUOTE (nprev @ Jan 16 2007, 09:40 AM)

Not to be greedy, but what the heck: Here's hoping for a nice series of nucleus fragmentation events to jump the coma magnitude off the chart & beef up the tail!

Yeah, I've been hoping for that too.

Second attempt last night, short story I saw it!

Long story...

Arrived at The Gap about 40 minutes before sunset, which from this position was going to be right over the city.

http://www.physics.usyd.edu.au/~jcanvin/mcnaught/P1050748_resize800.jpg

While waiting I was amazed when we were joined by the famous (in Australia ) author, TV & radio presenter http://www.abc.net.au/science/k2/ and his family. And what a great bunch they were, it turned the whole event into a bit of a party on the hillside. I was amazed to find out that Karl had never seen a comet before and given his enthusiasm for science, it was a pleasure to be with him for this.

After the sun had set it was obvious that looking across a city of 4 million wasn't the ideal way to see a comet! But given how bright it's supposed to be we weren't too worried. Finally saw it about 5 minutes after sunset, and then spent about 5 more minutes trying to explain where everybody should be looking "You see the fourth spire to the left of centrepoint..."

Here's an image from 10 minutes after sunset of McNaught heading for one of the only clouds in the sky!

http://www.physics.usyd.edu.au/~jcanvin/mcnaught/P1050773_82.jpg

And an enhanced greyscale version showing the limit of what was visible.



We then lost the comet behind said cloud before getting a quick glimpse of it close to the horizon over the city, soon after it was lost in the haze/smog layer.

http://www.physics.usyd.edu.au/~jcanvin/mcnaught/P1050795_8.jpg

James

Posted by: jamescanvin Jan 17 2007, 02:43 AM

Still, as it moves to darker skies it should be pretty spectacular for a few days yet.

Posted by: El Mitico Jan 21 2007, 01:48 PM

QUOTE (Mongo @ Jan 7 2007, 12:40 AM)

Here is a list I made for my own amusement some time ago, of the greatest naked-eye comets of the last two centuries, visible to observers in the northern temperate regions. I used a points system as follows:

MAGNITUDE: 10 points for every degree of magnitude brighter than +3 (dark-sky; daytime magnitude gets counted separately)

TAIL: 1 point for every two degrees of length of naked-eye visible tail in dark sky

DURATION VISIBLE: 1 point for every month naked-eye visible in dark sky

BONUS POINTS:
2 visible tails = 10 points
5 visible tails (West 1976) = 20 points
15 degree long anti-tail (Arend-Roland 1957) = 10 points
curved tail (Donati 1858) = 5 points
'bright' tail (Daylight 1910) = 10 points
'brilliant' tail (Ikeya-Seki 1965, Great September 1882) = 20 points
circumpolar all night (Hyakutake 1996, Tebbutt 1861) = 10 points
Mag. -3 in daylight (West 1976) or Mag. -5 in daylight (Daylight 1910) = 10 points
Mag. -8 in daylight (Great March 1843) = 15 points
Mag. -15 in daylight (Ikeya-Seki 1965) or Mag. -17 in daylight (Great September 1882) = 30 points

1861 123 pts Tebbutt
1882 101 pts Great September Comet
1910 95 pts P/Halley
1976 90 pts West
1996 78 pts Hyakutake
1997 73 pts Hale-Bopp
1858 68 pts Donati
1965 64 pts Ikeya-Seki
1970 61 pts Bennett
1957 57 pts Arend-Roland
1910 54 pts Daylight Comet
1811 52 pts Great Comet
1843 50 pts Great March Comet
1874 46 pts Coggia
1881 42 pts Great Comet
1807 37 pts Great Comet
1853 37 pts Klinkerfues
1835 35 pts P/Halley
1957 35 pts Mrkos
1860 31 pts Great Comet
1911 29 pts Beljawsky
1911 28 pts Brooks
1819 25 pts Tralles
1854 24 pts Great Comet

Here is the same list in reverse chronological order:

1997 73 pts Hale-Bopp
1996 78 pts Hyakutake
1976 90 pts West
1970 61 pts Bennett
1965 64 pts Ikeya-Seki
1957 57 pts Arend-Roland
1957 35 pts Mrkos
1911 29 pts Beljawsky
1911 28 pts Brooks
1910 95 pts P/Halley
1910 54 pts Daylight Comet
1882 101 pts Great September Comet
1881 42 pts Great Comet
1874 46 pts Coggia
1861 123 pts Tebbutt
1860 31 pts Great Comet
1858 68 pts Donati
1854 24 pts Great Comet
1853 37 pts Klinkerfues
1843 50 pts Great March Comet
1835 35 pts P/Halley
1819 25 pts Tralles
1811 52 pts Great Comet
1807 37 pts Great Comet

Bill

According to bill's scale, I rate Mc Naught

Magnitude -5 : 80 points (not sure if this is correct, maybe I should rate -2 for dark skies or less?)
Tail: 10 points
Duration: 1 point

BONUS POINTS:
15 degree long anti-tail (Arend-Roland 1957) = 10 points
curved tail (Donati 1858) = 5 points
'bright' tail (Daylight 1910) = 10 points
Mag. -3 in daylight (West 1976) or Mag. -5 in daylight (Daylight 1910) = 10 points

Total: 126 (or 96?)!

Bill...please rate it!

Posted by: Stu Jan 21 2007, 06:12 PM

I don't think we're going to see mcNaught from Mars... nothing's showing up on the Pan- or Navcams so far... so here's a little bit of make believe...

Posted by: El Mitico Jan 21 2007, 08:22 PM

QUOTE (Mongo @ Jan 21 2007, 01:12 PM)

The total to date would be 96 points (I had not heard that it had a prominant anti-tail, so I have not given points for that. Was there a report of one visible?)
Bill

Thanks bill!. About the anti-tail, it was my mystake. I had a missconception of what an anti tail was. No anti tail is seen in this comet so long.

Posted by: Tesheiner Jan 22 2007, 08:55 AM

QUOTE (Stu @ Jan 22 2007, 12:01 AM)

Wow... http://www.nightskyhunter.com/mngs7-7.html has it all... Comet tail, Milky Way AND zodiacal light...

The link doesn't work for me.

Posted by: ugordan Jan 22 2007, 09:43 AM

Works for me. Here's the image in question:

Posted by: Mongo Jan 22 2007, 05:06 PM

I wrote this in an earlier post:

QUOTE (Mongo @ Jan 21 2007, 04:12 PM)

If its visible tail grows to 50 degrees, it would tie with the 1882 comet, and if in addition it remains visible to the naked eye for a total of two months, it would surpass it, becoming the Greatest comet since Tebbutt (1861) -- at least when measured by this point system.

The visible tail of McNaught continues to grow. From
http://tech.groups.yahoo.com/group/comets-ml/message/11691:

QUOTE

Tonight the top of the tail has continued its apparent pivoting motion
around the nucleus such that the arc now reaches above Epsilon Gruis,
and Formalhaut is close to the centre line of the tail. While the tail
is still bright from the nucleus to the central line of the
constellation Grus, it becomes faint and was lost in the horizon haze
about 58 degrees from the nucleus. Following the centre of the curve a
visible tail length of 65 degrees can be measured. The arc from the
nucleus forming the bottom edge of the tail has not moved as much,
causing the tail appear wider. A tail width of 22 degrees can be
measured before the tail goes below the horizon.

I will count this as 58 degrees, with some unquantified additional visible tail length not yet visible from the southern hemisphere.

This alone brings the comet from 96 points to 105 points by the scoring system I am using, with further increases almost certain. This changes the current top-ten Great Comet list for the last 450 years into this ranking:

1744 144 pts Klinkenberg
1577 138 pts Brahe
1861 123 pts Tebbutt
2007 105 pts McNaught
1882 101 pts Great September Comet
1910 95 pts P/Halley
1769 91 pts Messier
1976 90 pts West
1618 89 pts
1680 83 pts Kirch

This is no realistic chance of McNaught passing Tebbutt in my opinion, but it could still gain a few more points in the coming days. It already has accumulated enough points, though, that I am fairly comfortable calling it a 'once-in-a-century' comet.

Bill

Posted by: Stu Jan 24 2007, 03:24 PM

QUOTE (dvandorn @ Jan 24 2007, 03:21 PM)

Hamner-Brown er, McNaught...

Laughed so much when I read that I dropped a choccie digestive in my tea!

Posted by: Pertinax Jan 24 2007, 04:51 PM

QUOTE (dvandorn @ Jan 24 2007, 10:21 AM)

No, I've been assured that there is no chance of any impact on Earth of any pieces of comet Hamner-Brown er, McNaught...

I had no visions of anything quite so dramatic (though I have been craving jerky... hmmmm) -- rather distant hopes of a nice meteor (not meteorite) storm.

-- Pertinax

Posted by: Tman Jan 24 2007, 07:27 PM

QUOTE (Stu @ Jan 24 2007, 02:25 PM)

All true, Mr Data, but it's still gorgeous...

Yeah, very nice Stu! It is the most gorgeous one to me (too) so far.

Any chance for a bigger version of it?

Posted by: dvandorn Jan 24 2007, 09:26 PM

QUOTE (Mongo @ Jan 24 2007, 02:30 PM)

...so: where is the mass coming from??

Must be non-baryonic dark matter...

-the other Doug

Posted by: Mongo Jan 24 2007, 09:34 PM

QUOTE (dvandorn @ Jan 24 2007, 09:26 PM)

Must be non-baryonic dark matter...

Hmmm ... are they properly accounting for the effects of General Relativity?

Bill

Posted by: climber Jan 25 2007, 06:34 AM

Here is my (very very very) modest contribution on the knowledge of comet Mc Naught :

Picture taken on Jan 14th 2007 from Kauaii Island.
I wouln't say "enjoy" but well

Posted by: Pertinax Jan 25 2007, 01:27 PM

QUOTE (Tesheiner @ Jan 24 2007, 11:56 AM)

Now seriously, the comet's orbit is perpendicular to the solar system plane so there is no intersection with the earth's orbit. No chance of a meteor shower.

Many Thanks -- That is what I thought, though I wanted to ask none the less as my expertiese of matters aloft ranges in the meters to km rather than AUs.

-- Pertinax

Posted by: fredk Jan 25 2007, 05:23 PM

I think that the continued breakup of particles in the tail is actually quite apparent in the images from STEREO. The point is that the synchrones deviate significantly from the radial-to-sun direction. But when particles break up in the tail, the smallest debris will feel a greater solar-wind-induced acceleration than their parent (larger) particles. So you expect new features in the tail which are not parallel to the original synchrones.

Basically, think of the larger particles in the main synchrones in the tail as mini-nuclei. When one of these breaks up, you get a new synchrone which is not parallel to the parent synchrone, since the orbit of the mini-nucleus does not coincide with that of the main nucleus. The new synchrone will be closer to the current antisolar direction.

All of this is quite clear from the STEREO http://www.unmannedspaceflight.com/index.php?s=&showtopic=1682&view=findpost&p=81224 (and I think in the best earth-based images too). These are from the 16th and 17th:

Posted by: fredk Jan 25 2007, 07:14 PM

QUOTE (ngunn @ Jan 25 2007, 01:47 PM)

The tail material is not remaining along the comet's orbit but migrating outward on the solar wind. It will thus eventually form an uneven sheet in the plane of that orbit and the Earth's orbit certainly intercepts that plane.

That's very true, but it still matters how close the two orbits get. McNaught crossed the ecliptic near perihelion, when it was well inside Mercury's orbit, so any tail material has to do some serious interplanetery travel before it reaches us.

Nevertheless, I estimate we cross the plane of the comet's orbit (on the outward side) around December 20th. Mark your calendars.

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