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The Great Christmas Comet of 2011, 2011 W3 (Lovejoy)
Mongo
post Dec 19 2011, 02:15 AM
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For those readers who are in the southern hemisphere, here is a finder chart for Comet Lovejoy from latitude 35 degrees south, for this Tuesday morning before sunrise:



This is from Where to look for Comet 2011 W3 (Lovejoy) Tuesday morning
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Mongo
post Dec 19 2011, 02:14 PM
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From Malargue, Argentina this morning:

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Mongo
post Dec 19 2011, 08:44 PM
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Finder chart for 35 degrees south on Wednesday morning:

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Stu
post Dec 19 2011, 09:30 PM
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Tail sighted - and photographed - from Australia...

http://www.spaceweather.com



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Mongo
post Dec 19 2011, 09:45 PM
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This is interesting. From the comet-ml mailing list:

QUOTE
On classical V-filtered pictures from 30-cm Meade SCT F/10 (0.66x) are more features visible today!

Some faint "outer tail" is now visible and there is something new, which looks like a ray in tail from nucleus looks like a synchrone.


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nprev
post Dec 20 2011, 04:06 AM
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Magnificent!!!


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machi
post Dec 20 2011, 10:06 AM
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Amazing images, it's unbelievable, that this little comet survived flyby so close to Sun! rolleyes.gif


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tasp
post Dec 20 2011, 02:06 PM
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Impressive it withstood the tidal effects too.
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Mongo
post Dec 20 2011, 06:59 PM
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Latest today from comet-ml mailing list:

QUOTE
Hi all,

I observed Lovejoy this morning from Woolbrook, NSW, i am so excited, at 4am AEDST i took an image of the Eastern horizon and upon looking at the image i noticed a thin "search beam" like extension pointing up from the SE, tilted a little to the North. I looked with my naked eye and saw what appeared to be headlights of a car near my horizon but it didn't seems to move, long story short....the tail i measured over the next 50 mins was nearly 15 degrees long and in moonlight!

Clouds not long intervened at dawn and i tried for the comet head but saw nothing in my 10" dob.

Images to follow!

Cheers,
Chris Wyatt
Walcha, NSW
Australia


The comet, as expected, is getting more prominent as it starts to move out of the morning twilight.

The thread title is "The SOHO Birthday Comet", but I think a better name would be "The Great Christmas Comet of 2011", since with the new moon on December 24th, viewing conditions should greatly improve just in time for Christmas. Not to mention that by then it should be well clear of the morning twilight, and significantly closer to Earth with a better viewing geometry.
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nprev
post Dec 20 2011, 07:45 PM
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In moonlight, no less.

Good grief. ohmy.gif


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Mongo
post Dec 20 2011, 08:40 PM
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Finder charts for 35 degrees South latitude on Thursday morning:

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jamescanvin
post Dec 20 2011, 09:45 PM
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QUOTE (Mongo @ Dec 20 2011, 06:59 PM) *
The thread title is "The SOHO Birthday Comet", but I think a better name would be "The Great Christmas Comet of 2011"


I agree, I added the "2011 W3 (Lovejoy)" subheading earlier today to help identify the thread and have now changed the main title to your suggestion.


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Mongo
post Dec 20 2011, 11:51 PM
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Oh-oh. That title change may have been premature. It appears that the comet nucleus may have broken up within the past few hours.

From comet-ml post #18949:

QUOTE
Comets gets weaker, today pictures in V-filtered exposures giving at 20.34 UT: ~3.5 mag (comparsion tar TYC 7364-2287-1 ).

Filtered images from FRAM this morning (average of best pictures).

http://www.kommet.cz/datas/users/1220average_r_dbe_1.png

http://www.kommet.cz/datas/users/1220average_v_dbe_1.png


From comet-ml post #18950 by Gary Kronk:

QUOTE
These are very interesting images. Either the nucleus and bright tail ray have been merged during the processing of these images or the distinct nucleus has broke up...appearing like a bar. This latter description has been given before when nuclei have been reported to break up.


From comet-ml post #18952:

QUOTE
This animation from Karl shows the comet fading in STEREO HI1A. A dust tail wedge is getting longer and broader, sits on top of original dust tail. There is a small recurring spike tail near and below the head that seems to be from a rotating nucleus.

http://sungrazer.nrl.navy.mil/index.php?p=...18\_19.gif

Where would all the new dust be coming from? There rate of new dust tail extension is occurring rapidly. Possible breakup starting?


From comet-ml post # 18955 by Gary Kronk:

QUOTE
The sudden appearance of bright rays are not uncommon when it comes to a comet breaking up. Check out the following link on my Cometography web site that discusses comet C/1999 S4 (LINEAR):

http://cometography.com/lcomets/1999s4.html

If you scroll down a bit, you will see two pictures from 1999 July 21, that show a bright tail ray. Within days the comet was unmistakably breaking up.

By the way the link to my comet Lovejoy web page is as follows:

http://cometography.com/lcomets/2011W3.html

Sincerely,
Gary
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Mongo
post Dec 21 2011, 12:27 AM
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A photo from this post:

QUOTE
After reading Ian Cooper's post I decided to drive south to the Mandurah Esturary around 2 am for a look. Light pollution is pretty low down there. I took 2 cameras, 1 for timelapsing and the other stills. I started taking images around 2:50 WST. At around 3:10 the first hint of tail appeared above the trees and by 3:15 I could see it visually. It stayed in clear view (non averted vision) from then until around 4:10 (deep twilight). An awesome sight. [...] If you're lucky enough to have clear skies tomorrow, I urge you to go out before the onset of astronomical twilight. If the comet is anything like it was this morning you won't be disappointed.


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Mongo
post Dec 21 2011, 12:52 AM
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From comet-ml post #18958:

QUOTE
Hi all,

When I first looked out this morning (from Cowra in central NSW) and saw the layers of high and middle-level cloud, I almost went back to bed. But after a few minutes deciding, I set up the 25x100 binocular telescope and started to sweep along the horizon which, surprisingly, was clear for the first two or three degrees. At 4.20 local summer time (1720 UT) I noticed something like a distant searchlight beam rising over the slope of a small hill which sports the rather grandiose name of "Porter's Mount". With the sky becoming bright, I could see a clear feature on the local horizon (a tree about two thirds of the way up the grassland slope of Porter's Mount) near where the beam emerged and, finding this without the telescope, I could then see about 2 - 3 degrees of tail rising up to a bank of heavy cloud. The tail must have been quite intense to be seen in such a bright sky and, from the calculated position of the head, at least 7 - 8 degrees long (although most of this was not seen. Neither was the head as the sky had become very bright by the time it would have cleared Porter's Mount).

On a slightly different topic, as one of the few Ikeya-Seki veterans in this group, it is probably timely to sound a warning not to give up on this comet because of the degree of fading that has obviously taken place. Back in 1965, the arrival of I-S at perihelion was surrounded by a lot of media hype. Predictions that a comet brighter than the Moon was coming, while they turned out to be technically true, failed to make clear that the comet would be only a few arcminutes from the Sun's limb at that time and would fade very rapidly afterwards. Of course, the general public missed much of the display at perihelion and dismissed the comet as a dud. On the day of perihelion, Fred Whipple called it "a scientist's comet"; one that was great for astronomers but a disappointment for the public. Unfortunately, the media dropped the subject (by and large) and when the "public" show occurred over a week later, only those who normally rose before dawn for work or other purposes saw it.

My first couple of views post perihelion were not all that exciting. High cloud always seemed to shroud the eastern horizon and by the time the comet cleared this, the sky was very bright and the comet looked washed out with only a small diffuse spot of a coma and a fading tail. Then, exactly 10 days after perihelion, there was a morning of exceptional clarity and by that time the comet was far enough from the Sun to be rising in a dark sky. The sight was magnificent. In the dark sky, the coma appeared brighter than the earlier twilight views and looked small and dense. As for the tail, this appeared (as John Bortle has written on several occasions to this group) "solid", not diaphanous like the tail of a normal comet. And there was little "normal" about Ikeya-Seki! Today, we would probably think of laser beams or Star-Wars light sabres ... but this was back in 1965!!

Now, I am certainly not saying that W3 will become as remotely spectacular as I-S, but the lessons of 1965 are worth noting. The comet may become faint, but the tail may well retain relatively high surface brightness for quite some time and be impressive in coming days as it pulls out from the twilight (and moonlight). Don't dismiss this comet just yet! There may still be surprises in store.

David


In response to this, John Bortle wrote in comet-ml post #18961:

QUOTE
David is absolutely correct. I anticipate that the spectacle is only likely to grow better with time as the tail moves out of the morning twilight. Keep in mind that the brightness of a sungrazer's dust tail seems to fade much more slowly than does that of the coma, following closer to a rate dictated by the inverse square law. Likewise, Comet Lovejoy's tail is more-or-less still approaching Earth as the comet retreats from the Sun, slowing the fading process even further.

Go back and consult some of my earlier posts concerning the development of Comet Ikeya-Seki's post-T dust tail. Such may well foreshadow the sort of evolutionary path that the tail of Comet Lovejoy may see in days to come on a somewhat more modest scale.

Folks, be assured that the show isn't over yet by any means.

J.Bortle
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