Help in identifying a (new?) comet in Sagittarius…
Hello,
Tonight, August 8th 2008, whilst taking a photo of the Hubble Space Telescope passing by Jupiter I noticed a faint blue object near the recorded trail of the HST. The FOV is approx 2 x 1.25 degrees.
Subsequently, I took several other photos of the object and it shows distinct movement as show in the attached composite image.
I have tried a quick search using my normal software and could not locate a current comet in this position.
Thanks for that. That particular one didn’t come up on my various searches and with it being such a bright object, I figured that the chances are it was an existing one, although my heart did skip a beat or two when I first spotted it!
I just plotted C/2007 N3 Lulin in The Sky and it is over 3 degrees away from where I have recorded it in the photos. Can there be this much of an error in reported positions?
I just plotted C/2007 N3 Lulin in The Sky and it is over 3 degrees away from where I have recorded it in the photos. Can there be this much of an error in reported positions?
Cheers
Dennis
Dennis , I don't know the field of your photo but my copy of THE SKY gives the seperation of the Comet
From Jupiter: as
Angular separation: 04°07'33"
Position angle: +293°28'
Is that what you get?
It is a very fast moving Comet.
When did you update the ephemerous for the comet?
Ron
Yes,I am at a loss to explain the anomalyexcept maybe as it is close to the Zenith, could it be the shortening affect
Or maybe there is another Comet that you may have Discovered
Ron
Yes,I am at a loss to explain the anomalyexcept maybe as it is close to the Zenith, could it be the shortening affect
Or maybe there is another Comet that you may have Discovered
Ron
Hi Ron
Thanks for your help – I’ll sleep on it and start the search afresh tomorrow. I should really have slewed to the plotted position of C2/2007 N3 Lulin in The Sky just to check if it was there, but I packed up a while ago.
The 400mm L makes for a nice wide field APO dennis, whack it on your EQ mount and get some deeper shots of your comet!
Thanks Alex – it was riding on the eq mount and I’ve collected a few 60 sec, 120 sec and 600 sec exposures. The light pollution looks ghastly on the raw frames!
I can't help but wonder about an internal reflection, as it seems to be opposite Jupiter in all of your shots. However, the colour is very cometary, and the direction of motion seems consistent.
The calculated FOV for your configuration is 190x127 minutes. The approximate coordinates for the object at 21:03 are: 18h59m49s DE:-21°17'48"
Thanks Eric, I appreciate your help and comments. I did a very quick and dirty alignment of some of the sequences I captured last night and the path of the “comet” appears strongly curved and seems to “wander” rather than move in a straight line.
Along with what appeared to be 2 or 3 faint tails, this also led me to believe I may be looking at some optical artefact, pending a more high fidelity alignment and animation which I’ll try later.
Okay. Here is an animation of 10 frames captured from 9:40pm to 10:19pm. Each frame is a 120 sec exposure with a 2min 20sec delay between captures to allow for In Camera Noise Reduction and download time.
The region has been cropped severely and levels stretched to reveal the “spiky” nature of this mystery object. Looking more like an optical system artefact based on its wandering and the radial spikes?
Bad luck Dennis.
But hey, didn't it give the heart and mind a workout for a while.
Good to see a systematic approach to solving the image. Good teamwork from IIS members too.
Keep at it -not all will be artifacts.
Nice sharp stellar images.
I’ll probably drive the final nail into the coffin of this “comet” by going out tonight to image the same region with the same set up and then rotate the 40D/400mm F5.6 lens combo 90° and 180° to see what turns up. Something I should have done last night with hindsight.
Here is a crop from the full frame, of a histogram stretched 5 minute exposure revealing the true nature of this imposter! If the stars weren’t so tight, I’d return this lens, as I figured no Canon “L” lens should show signs of lens flare!
except maybe as it is close to the Zenith, could it be the shortening affect
