Stargazers in for a treat as green comet 'the size of Jupiter' streaks past Earth tonight

I think I see it! it is uber dim though, but then I am in a city. It appears to me to be just to the right of Saturn if I'm looking at the right thing

cool thread by the way.

No reports yet?

Bummer

Originally posted by -NewSense-
So we're not sure if it will be visible? Or atleast, entertainingly visible?

Probably not entertainingly visible to the casual observer. To a telescope nut, yes.

If its the same size can't we judge its brightness by the distance of jupiter and lulin?

No, because Jupiter is decidely more solid and reflective than Lulin's thin coma.

Lulin: 38 million miles

Jupiter: ??????

That blank should be filled by the number 550 million miles

My scope is training out the periodic error at the moment. When that is done I will begin to image the comet. In the viewfinder it appears to be a dim little smudge.

[edit on 23-2-2009 by ngchunter]

Here's my image of Lulin from last night, I'll also be working on a more traditional "streaking stars" version of this photo later tonight.
[atsimg]http://files.abovetopsecret.com/images/member/10f6b71fe9ee.jpg[/atsimg]
The comet put on a great show, moving fairly rapidly through the field of view. Couldn't spot it naked eye though, but it was obvious in the viewfinder.

Pardon my ignorance but a comet - the size of Jupiter? Surely, surely not!

Repeating an earlier post it must be the size of Jupiter when observed by Earth dwellers but it's not that clear. Then again - Daily Mail.

reply to post by vonspurter


The comet's coma is the size of jupiter, not the physical body itself. That's what all the papers are referring to. I can confirm the former. The comet moved about 1 arcsecond every 5 seconds last night (which was rapidly apparent in my 1 minute long images), and using that info I was able to calculate the size of the coma to be 570 arcseconds wide, based on just what my scope could detect in the above image (calculations were done using a higher resolution version, of course). 9.5 arcminutes 38 million miles away means:
38 million x 9.5 / 3438 = 105,000 miles wide. Jupiter is 88,700 miles wide.

[edit on 24-2-2009 by ngchunter]

Here is the link to Stellarium. It is free. It will not show the comet, but will help you to orient yourself to the heavens. You set it up with your location and time and it displays the heavens from where you are in real time. Quite handy and free to boot.

reply to post by groingrinder


This reminds me of the movie "Maximum Overdrive" by Stephen King.
Hope my ceiling fan doesn't disconnect from the ceiling tonight and try to eat me!

reply to post by ngchunter


Nice shot NGC. Thanks for sharing.

What was you're exposure time/F-stop?

If I can track down some clear sky in the next couple of days, I might have a go at Lulin myself.

reply to post by C.H.U.D.


I used 32 x 1 min unguided subexposures at f/10. The anti-tail has faded quite a bit so it doesn't show up much with those settings. The main tail is much brighter when I stack it tracking on just the comet, rather than both comet and stars, so I'm looking forward to finishing that version tonight.

It was initially an infuriating night; tracking was way off even though I nailed the polar alignment. I had retrained the PEC and I probably had it set too aggressively, so I wiped the memory and retrained again with a slightly defocused star so it wouldn't chase the messy seeing (little trick I learned online). That seemed to help a lot and enabled 1 min exposures instead of 30 seconds at best.

reply to post by ngchunter


Cheers NGC.

Sounds like I've missed my opportunity to capture both tails. I probably didn't stand much chance anyway as I'm quite inexperienced at photographing comets (or any object that needs to be tracked for that matter), and it's rare that the weather cooperates.

I forgot to ask - what ISO also?

Its the size of Jupiter?

Is that correct?

A body that massive moving at that speed?

If the size of Jupiter, then it must have an immensely powerful gravitational field... Much smaller commits have gotten within a few millions miles of Jupiter and been broken up by Jupiter's mass and gravitational field.

If it is that indeed that big I wonder what effects it could have on our solar system's planetary orbits etc?

reply to post by Walkswithfish


The ball of gas surrounding the nucleus of the comet is very diffuse . The mass of the comet is nowhere near that of Jupiter.
science.howstuffworks.com...


[edit on 2/24/2009 by Phage]

Originally posted by C.H.U.D.
Sounds like I've missed my opportunity to capture both tails. I probably didn't stand much chance anyway

You and me both. It's probably against board rules to say which part of my anatomy I'd give to have a good wide field APO mounted on top of my scope for getting the "big picture" at times like this.

I forgot to ask - what ISO also?

ISO 1600. I figured since the comet's fast motion made it streak a bit even at 1 minute, I needed every photon I could get into each well. Stacking 30+ exposures with 8 dark frames pretty much killed the noise level, thankfully.

Speaking of noise, I'd like to add that it was quite disconcerting to hear coyotes howling the whole time I was out there. They sounded quite close by, which isn't normal from my short experience.

[edit on 24-2-2009 by ngchunter]

Originally posted by ngchunter
You and me both. It's probably against board rules to say which part of my anatomy I'd give to have a good wide field APO mounted on top of my scope for getting the "big picture" at times like this.

I was looking at some super-fast Borg's a while back that seemed like they would be ideal for this kind of thing. Unfortunately I rushed into it some time back, and bought a 180/2 camera lens, which I have yet to test on the stars!

It's a quality lens, but a proper astrograph is always going to be better suited to this kind of work. It's taken me a while to realize that Still, I'm hoping it will be OK, perhaps closed down a stop.

Originally posted by ngchunter
ISO 1600. I figured since the comet's fast motion made it streak a bit even at 1 minute, I needed every photon I could get into each well. Stacking 30+ exposures with 8 dark frames pretty much killed the noise level, thankfully.

Yeah, I thought as much. I may have to try ISO 3200, which is a setting I usually try to avoid, but since stacking/DFS is the order of the day...

Originally posted by ngchunter
Speaking of noise, I'd like to add that it was quite disconcerting to hear coyotes howling the whole time I was out there. They sounded quite close by, which isn't normal from my short experience.

You're lucky. Over here we have foxes, which sometimes sound like a woman screaming like she's being attacked. Unnerving to say the least!

At least with coyotes you can keep a baseball bat(or even something with a bit more 'punch') next to you for comfort. I suppose you do have to watch out for mountain lions depending on where you are too though!

Originally posted by C.H.U.D.
At least with coyotes you can keep a baseball bat(or even something with a bit more 'punch') next to you for comfort. I suppose you do have to watch out for mountain lions depending on where you are too though!

No mountain lions here to speak of, the florida panther is exceedingly rare. We do have bobcats, but they don't usually attack humans. The only direct encounter I've had with wildlife while observing so far was a stray black cat that got into my tent one night. Scrared me senseless till I figured out what it was .

Here's the same image from before, but stacked on the comet so that the stars streak with the comet's motion between frames:
[atsimg]http://files.abovetopsecret.com/images/member/67560df6c5ec.jpg[/atsimg]
This makes the tail much more obvious imho, so I think I prefer it this way.

its been bludy raining here forever
thats a first.
Anyway no chance to have a view at all

[edit on 24/2/2009 by GEORGETHEGREEK]

That's an awesome view of this comet. Thanks for sharing.

I've gone out the last few nights only to be blocked by the clouds every night. I did get to finally see Saturn with my new Celestron telescope that I've had for 3 weeks now and have only had 1 day of clear skys.

Did anyone happen to get any pics of Jupiter, Mars and Mercury all within a small area this morning? Should still be pretty nifty the next couple of early mornings.

Also, whoever posted the pic of where the comet is in relation to Saturn, do you have more info of this sort? Like where will it be the next few nights?

Just went out to take a look.

I could not see it with the naked eye and i live in a fairly dark area (no city lights)

I thought i saw it a little past saturn, but im not sure. Ill wait till about 1:30 and get the binoculars out.

Great shots NGC... amazing.

Well done and thanks so much for posting them here.

Do you or have you submitted these pics to your local or regional news outlets?

If not, you should.. great pics.. and many have no idea it's up there