How long is Lovejoy around for?

[gregbradley]

How long will this comet be visible for?

I was planning to go to my dark site observatory on Monday. Will it still be around then or will it have faded significantly?

Greg.

[Liz]

per Terry today in the looong thread in Celestial Events -

The comet is still moving towards earth, and is closest at 0.5 AU in early January when the comet's coma will pass near the south celestial pole (nice!). I imagine the tail would have become quite weak by then and may be difficult to see.

This comet is very similiar to the Sungrazing Comets of 1880 and 1887, which remained visible only 3 weeks past perihelion. So if history is anything to go by then we don't have too much time to get the best views, maybe until the end of the year.

Terry

good luck Greg!!

[renormalised (Carl)]

All true, and then again it could be the exception to the rule. Comets can be very fickle things and they don't play by the rules

However, if the past is any indicator, then it'll probably go along the same lines as the others.

[gregbradley]

Ok, so that means in all likelihood it will still be quite bright early next week.

Still I may get up early tomorrow morning and see if the skies are clear enough to catch it.

Greg.

[Ric]

Hi Greg,

This post by Dave Herald was on the on Canberra Astronomical Society forum this morning. It looks like comet Lovejoy could be around for a while yet.

Hope this helps


Thought people might be interested in this ‘prediction’ of the future brightness of comet Lovejoy. It is by comet expert John Bortle.

If this holds up, we are in for a spectacular sight over the next few weeks. Note that the comet (specifically, its nucleus) gets to its most southerly point on Jan 8, at declination –88 deg. That is, for several weeks after about New Years day the comet will be circumpolar, and therefore visible all night.

This comet is a Kreutz sungrazing comet. For those who would like to learn more about what to expect from this comet, read about this group of comets at:
http://en.wikipedia.org/wiki/Kreutz_Sungrazers
http://en.wikipedia.org/wiki/Sungrazing_comet

For info - Comet Lovejoy had a perihelion distance of 0.0055 AU. This means it skimmed above the surface of the Sun at a distance of about 120,000km, or 1/3rd of the distance between the Earth and the Moon. The radius of the Sun is 696,000 km.....


Dave Herald
Murrumbateman, Australia


************


I am particularly taken by this latest image in that it almost precisely replicates images of Comet Ikeya-Seki from 1965. The match is nearly exact, right down to the distinctly brighter tail edges, the twists in the tail and even the faint outer sheath enveloping the bright dust tail. Such a feature was also seen in some of the drawings of the Great September Comet of 1882. Truly, Kreutz sungrazers are a group of comets absolutely unique unto themselves!

There seems to be some panic arising among folks currently experiencing cloudy skies down under, thinking that they may miss the whole show. Fear not, for as I pointed out previously although the comet's head will continue to fade rapidly, the tail will drop in brightness far more slowly. If it should follow the evolution of the tail of Ikeya-Seki, then the outer-most portion of the long dust tail will hardly fade at all over the next couple of weeks. However, the tail's middle section will, until it has faded to match the end portion. Then the entire tail will seem to fade as a unit. Remember too, that the tail will be continuing to grow throughout the period. I would anticipate the it might attain a final nakedeye length of ~25 degrees, by which time it will be very faint and difficult ghostly specter to the nakedeye.

I was interested to hear that David S. reports variations in the brightness of the tail over the course of a short time, a phenomenon referred to a coruscation. Such has been reported on rare occasions throught cometary history. Although usually attributed to atmospheric instability, some instances have been much harder to explain as such and if seen, it should always be recorded, along with details of the prevailing weather conditions.

J.Bortle

[Ric]

Originally Posted by renormalised

All true, and then again it could be the exception to the rule. Comets can be very fickle things and they don't play by the rules

However, if the past is any indicator, then it'll probably go along the same lines as the others.

Reminds me of quote by David Levy

"Comets are like cats, they both have tails and do whatever they want"

[Ian Cooper]

As I have posted elshwere on IIS this is for those who may have missed that thread. This morning (Boxing Day) the tail was out to 28 degrees. Based upon all of the recieved images and my own personal observations we could see the tail out to 34 - 35 degrees tomorrow morning. Most of the tail is circimpolar from my latitude (40S) and the head will be in a couple of days, although the whole thing will be lying on its side after dusk. The end of the tail should be almost next to The Pointers tomorrow morning. As the moon brightens each evening then the comet's viewing time weill keep shfting back into the morning before the Full Moon takes it out for about 4 days.

Best of luck,

Coops

[ath (Andrew)]

She was looking really faint this morning in Gippsland Victoria. (28/12/11) Even in relatively dark skies. Back in Melbourne now, might give her one more try this morning. Heres hoping for one last glimpse!

[tomtom]

You were in Gippsland too ath?
I didn't get to see her either. Went out for quite a few nights.
Back in Melbourne now too.

Pretty sad

Great viewing up there otherwise, though.

[Poita (Peter)]

I had no luck last night, hoping it will have a bit of a reprise!