Not as many stars in mine. Sky too bright! I can't believe how fast dawn crept up on me. Anyway, 8 x 20 seconds at ISO 400 unguided, Skywatcher 120mm F5 refractor, HEQ5 pro, from Thursday 3rd.
What is the current location of PANSTARRS. Is it in range of 10" Dob with hopefully clear and dark skies?
Aidan, the free programs Stellarium, CdC, and C2A (and probably others I don't have) all support in-program updates of their comet and asteroid databases. Provided the data has both the magnitude data values they will estimate the brightness you can expect.
At the moment it is at 17h26'03" -39°54'54" mag 9.2 visible from a bit after 03:00 AEDT.
Your best chance is probably in the fortnight around Jan 25 when it will be in the morning sky around 02:45 AEDT. CdC predicts Jan 18 mag 8.1, Jan 25 mag 7.4, Feb 1 mag 6.6.
Aidan, the free programs Stellarium, CdC, and C2A (and probably others I don't have) all support in-program updates of their comet and asteroid databases. Provided the data has both the magnitude data values they will estimate the brightness you can expect.
At the moment it is at 17h26'03" -39°54'54" mag 9.2 visible from a bit after 03:00 AEDT.
Your best chance is probably in the fortnight around Jan 25 when it will be in the morning sky around 02:45 AEDT. CdC predicts Jan 18 mag 8.1, Jan 25 mag 7.4, Feb 1 mag 6.6.
Unfortunately most (if not all?) planetarium programs update from MPC ephemerides. When a comet is discovered a preliminary ephemeris is prepared with orbital elements and a prediction of brightness behaviour based on a simple formula relating to some fundamental properties of the object and behaviour of similar previous objects. Even as the orbital elements are updated with new astrometry, the m1 predictions are not altered. Therefore if a comet goes into bright outburst or performs better than expected (or worse!), your planetarium program will continue to show the original MPC predictions. Thus we had Starry night, Stellarium etc showing mag 17 or something for comet 17P/Holmes when it was a naked eye object a few years ago, and planetarium programs continuing to give magnitudes for C/2011 W3 (Lovejoy) for months after the comet nucleus effectively ceased to exist.
To get an idea of how a comet is performing, you're better off going to a website with updated light curves. Here, the formula will have been modified to account for a stream of incoming observations. As a one-stop-shop, you can't really beat Seiichi Yoshida's site IMO: http://www.aerith.net/index.html http://www.aerith.net/comet/weekly/current.html (click 'South' link at top)
If you go to his C/2011 L4 page you'll see how the comet is going, and is likely to go, in the light curve at the bottom of the page: http://www.aerith.net/comet/catalog/2011L4/2011L4.html
Currently the light curve doesn't have the latest southern observations since the comet crawled out of daylight but you can expect that they'll be added in the next few days probably. Sometimes more than one formula will fit existing observations and you may see other sites using different formulae. But it is a constant refining process - prediction is not an exact science!
There are many other sources of updated comet information around the web, some good, some bad.
Quote:
Originally Posted by badabing82
So it's confirmed at m 9.1 or their thereabouts currently?
No, see above. Recent visual obs include m1=9.1 (23 Dec), 8.1 (24 Dec), 8.0 (27 Dec), 8.3 (1 Jan), and Terry's est of around mag 8 on 2 Jan - the comet is not fluctuating in brightness, this is just differences in what people see (exacerbated by low altitude, different instruments & moonlight). So the trend is that it appears to be a bit visually brighter than the ephemeris magnitude, so brighter than mag 9.1. And brightening all the time.
Cheers -
Last edited by Rob_K; 04-01-2013 at 02:15 PM.
Reason: Added obs
Hi Cheers for that yeah i use seiichi's site amongst others but as you said they are mostly northern hemisphere so not a great amount of info at this stage.
No idea how i totally missed the the trend i just saw the m=9.1 even though i read it was 8.x a few days ago! lol
Does anyone have a visual on this comet in the last day or so - Calsky is saying it is at mag 4.9 now
Comet 'C/2011 L4' Magnitude= 4.9mag
Best seen from 4.6h - 5.0h (htop=19° at SE at 5.0h) (in constellation Corona Australis)
RA=18h02m33s Dec=-42°24.5' (J2000) Distance to Sun= 1.32AU Distance to Earth= 2.07AU Elongation= 31°
hourly motion: dRA=102.7"/h dDec=-32.3"/h
I tried in the morning of 12th Jan by a small telescope (65mm in dia, focal length 420mm and 25mm eyepiece with magnification of 16.8), but failed. Might be due to the light pollution or fog...However can find it from the photo with 500D connected to the telescope (2s exposure, ISO 12800). Waiting for another clear night.
Cheers
Guodong
Quote:
Originally Posted by JetDragon
Does anyone have a visual on this comet in the last day or so - Calsky is saying it is at mag 4.9 now
Comet 'C/2011 L4' Magnitude= 4.9mag
Best seen from 4.6h - 5.0h (htop=19° at SE at 5.0h) (in constellation Corona Australis)
RA=18h02m33s Dec=-42°24.5' (J2000) Distance to Sun= 1.32AU Distance to Earth= 2.07AU Elongation= 31°
hourly motion: dRA=102.7"/h dDec=-32.3"/h
From the comet observing guys down south - it was observed this morning at mag 8.6. Alas, they feel it may not brighten as much as was predicted, but still may get get mag 2.
Any one observed Panstarrs lately?
What mag is it now??
Given the recent weather I doubt there have been many observations. Based on the numbers from JPL yesterday it should be something around 6.2
Using JPL's figures the prediction is for mag -6 on March 9th/10th.
From now until then it will be in the western sky for about an hour or so after sunset.
Here's an image I got of Panstarrs on Tuesday 29th. I had to wait for the comet to rise above some tall pine that surround my place. I was also competing against the morning twilight and the moon. I still managed to capture it though, which I was thrilled about.
Image taken through a William optics Megrez 90 Refractor and tracking with a HEQ5 PRO mount
Finally saw Panstarrs this am, had been too low for Northern Australia, and still pretty low here. A bit of cloud low in the south, but it rose above it, and quite easy to see with binoculars. Last estimate I heard was mag 5.1, and supposed to reach about mag 2-3 next month.
Thanks as always
! Thanks for the info, Dave.
