Kreutz SunGrazer Lovejoy

[Lester]

Hi Ian, good report and especially interesting that you could still see the comet with naked eye averted vision. Unfortunately cloudy here for tonight.

All the best.

[Lester]

Here is the same image inverted, and shows the length of tail better.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/144c4e29.jpg

[Rob_K]

Excellent Ian! Can confirm - to me the comet was naked eye in averted vision before moonlight killed it. I could see it as a faint bar of light extending as far as the Tarantula Neb end of the LMC.

Not much time tonight and I was fiddling with camera & mount for all of the best viewing and shooting time (mucking about with the alignment, getting the right field etc) so I didn't devote much time to visual, not expecting to see anything anyway. By the time I got everything going the Moon had risen and the subs were pretty washed out. Negative shows it best, confirms my visual sighting as far as position goes:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W312Jan2012invert.jpg

Tomorrow should be better if the clouds hold off. Next few nights have potential for great images, as the tail passes over the LMC.

Cheers -

[Liz]

Fabulous news there Ian!! I had thought it was well and truly done visuall, you must have good eyes though.

Excellent image there Rob, love it!! :thumbsup:

[Lester]

Hi all, at last clear dark skies. This is a 2 minute exposure with 50mm lens at F2, and Astro 40D at ISO 800. Looks like the tail goes well past the LMC. I could not see the comet naked eye, and the sky was very clear, as I could count easily 30 stars within Orion.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/844abef5.jpg

Inverted view.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/a580d233.jpg

[seanliddelow]

Great image Lester. Is it me or does Lovejoys tail extend past the Large Magellanic Cloud in the inverted view? Inverted images seem to reveal more detail then images that are not inverted.

Sean

[Lester]

Thanks Sean, yes there is a very faint hint of the tail going past the LMC.

Here is a stack of 18 x 2 minute exposures, inverted that shows the tail slightly better.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/3f8c5e14.jpg

[Liz]

Well done Lester, another great image, but as Sean points out ... look at that tail!!

I skimmed over the 1st images, but went back after Seans comment = wow!! Your new image shows it well, I wonder how many degrees the tail is now, as it looks looooong. :eyepop:

[kinetic]

Lovely shot Lester, it sure shows what a difference a darker sky and
no moon makes.
Here is my full frame set with the QHY-8 and 80-200mm SLR lens from
this morning.
Moon was well up, suburban Adelaide.

Maybe just a hint of tail when I stretch the full frame.

Steve

[Lester]

Thanks Liz and Steve for your comments. I will have to put the head of the comet closer to the edge of the frame next time, or even go back to the 24mm lens. Rob has measured the tail to extend for over 22 degrees on his image from last night.

Steve, I don't know if there is a filter that would help in your situation. I did pop the question on another thread a few weeks ago, but without any real answers.

All the best.

[Rob_K]

Not the greatest conditions here last night - clear but transparency was a bit off. Nothing naked-eye really, but did get an image. Squeezed a bit it shows faint trace of the tail out to 21-22 degrees with the last little bit out to the edge of the frame lost in vignetting (quite possible) or not there. Anyway, still over 20 degrees long.
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W313Jan201211-27UT55mmfullinvredb.jpg

Here's my 'pretty pic' shot (crop) - not so pretty, eek....
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W313Jan201211-27UT55mmcrop.jpg

Like Lester, I will shoot wider tonight if conditions allow. His shots are superb! :thumbsup:

Cheers -

[kinetic]

Wow Rob, great shots, the tail on the negative is so impressive.
Great documentation of the last weeks of this sungrazer guys!

Steve

[Rob_K]

Thanks Steve. :thumbsup: I shot wider tonight (18mm), and I think you can safely say the tail is at least 37 degrees long, possibly out to 45-46 degrees, and if it persisted after that it's lost in the bright Milky Way starfield. Tonight the tail was going right over Canopus. Visually I couldn't see anything of the tail.
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W314Jan2012taillength.jpg

At 55mm the tail extends faintly out of the bottom-left corner of my frame, a length of 20 degrees:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W314Jan2012taillength55mm.jpg

My gear isn't really suited to this stuff - a basic, old entry-level DSLR with cheap lenses, on a rickety unmotorised EQ1 mount and 'guiding' through a reticle with the slo-mo knob. It would be great if someone could repeat this with a halfway decent imaging rig - waiting on Lester, hopefully he's done the business again! :)

Cheers -

[Lester]

Hi all,

Shot the comet last night in windy conditions with cloud causing lots of frames to being useless. This was taken with 24mm lens at F2, and Astro 40D at ISO 400 with 8 minute exposure. I wanted to try some 12 minute exposures, but cloud arrived. I should have had the comet further to the right in the FOV, as the tail extends out of the frame being over 36 degrees in length. I notice a fork tail in the thumbnail with one extention going above Canopus.

I have just taken flat frames for the first time, with a piece of white cotton material over the end of the lens, pointed at the sky. Using the same F ratio,focus and ISO as last night images. Standard exposure with histogram central, took 10 frames and added them into the mix for DSS. The result seemed to reduce the vignetting very well.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/dc10a80c.jpg

[Liz]

Fabulous shots again guys!! Look at that tail piercing Canopus and LMC, amazingly long and well measured for us Rob. :thumbsup:

[CometGuy]

Doing well there Rob and Lester. I tried last night but too much scattered light and cloud to image the tail. It is just so faint now.

btw I've downloaded the fits files from hubble made on January 7, but alas nothing clearly visible. But boy they are noisy with all the cosmic ray strikes and the field of view is only 3' so I'm not sure if the were on target or not. Maybe with further processing something might show up. Congrats to Matthew Knight from Lowell observatory for getting time on the hubble!

Terry

[Lester]

Thanks Liz and Terry.

Here is tonights image, 15-1-12. 5 x 12 minute exposures at ISO 400 with 24mm lens at F2. If the tail reaches the edge of the frame it would be just over 47 degrees long. I am not sure if it goes that far, but Rob will process it a bit more and see how far it goes.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/47a04e12.jpg

[kinetic]

My 30 sec x 100fr set from tonite, 15th Jan
60 sec x 50 frame set still to process

Steve

[glenc]

The very faint tail in Lester's image is about 22 degrees long, the "brightest" part is about 5 degrees.
The greenish Vela SN remnant is visible on the lower left side of the image.

[Liz]

Great images Lester and Steve. :thumbsup:

yes, that tail zooms right past Canopus Lester. :thumbsup:

Interesting re Vela SN remnant Glen. :)

[Rob_K]

Hi Glen - I make it out to 43 deg and more than probably extending out of frame, 45 deg + (per link below). The Milky Way interferes right near the edge of the frame, a bit hard to tell.
http://i727.photobucket.com/albums/ww271/Rob_Kau/Untitled-1lestertaillengthsm.jpg

Interesting, how do you all estimate lengths? I use the measuring tool in Starry Night. Should be very accurate as it's pretty simple maths - angle subtended at centre by two points on a sphere.

Clouds interfered last night so I got nothing. Great job again Lester! :thumbsup:

Cheers -

[Lester]

Top work again Rob. It would be interesting to know how long the tail is in KMS. No wonder it is fading quickly, the ice-cream is nearly finished.

Thanks for your input too Glen.

Nice image Steve, looking forward to the processed version.

Thanks Liz for your comments also.

All the best.

[swannies1983]

People are still imaging Lovejoy? Talk about dedication. Well done guys :thumbsup:

[Lester]

Thanks Dan, it keeps me off of the streets at night and from getting into trouble.

[Rob_K]

Despite great dark skies tonight and imaging deeper than I have before, I could only trace the tail to about 5 degrees past Nu Puppis, or 34 degrees in total (subs centred on 11:52 UT, 16 Jan). Canon 400D, 18mm, 5x and 4x 3.5 min, ISO 1600, F/3.5.

Very, very faint trace at that, and not even as far as the Milky Way. I shot two fields covering from the LMC to way past Procyon just in case there was a hint of anything on the other side of the Milky Way. That's about it for me on C/2011 W3, it's continuing to fade and I've pushed my humble gear to the limit.

I've been in touch with Lester and he decided to do an extra night, same objective in imaging across the Milky Way. He'll have more conclusive results than me, but we'll just have to wait to see what he got.

Cheers -

[pixelsaurus]

I had a squizz about 2 hours ago with 20X80's and not able to see any trace of Lovejoy. Moon was low in the east but sky clear, LMC and SMC easily visible.

[kinetic]

Rob, Lester, all,

becoming a real challenge now from LP Adelaide skies.

tonight's 30sec x 100 frame set, QHY8/lens

Steve

[luigi]

I went to say good bye to Lovejoy on January 14th.
The Comet was accross the LMC tail extending up to Canopus.
Invisible to the naked eye or binos but ok to the Camera (barely)

Stack of 10x60s at ISO1600 14mm:
http://www.luisargerich.com/lovejoy/h297dc105

Stack of 50x60s at ISO1600 50mm:
http://www.luisargerich.com/lovejoy/h297dc105#h76abb75

Same with Inverted Color:
http://www.luisargerich.com/lovejoy/h297dc105#h18fd4bd2

I could have masked the LMC a little before stretching but well it´s about the comet isn´t it? :)

Luis

[Lester]

Top stuff again Rob, to get the tail out to 33 degrees is still Very long. I shot at 1600 ISO with 4 minute exposures last night and 24mm lens at F2. Could see the tail on the rear view screen of the camera to well past Canopus. Did 3 Fov across to Sirius, but like you couldn't detect the tail near the MW.

Yes it is very faint, your inverted images Steve and Luis show the tail well. Mike, IMO any Moon, or stray light/pollution will make viewing the comet a no show. 80mm aperture binoculars should be a chance in dark skies, but the 20x magnification my yield too small a FOV to really show the comet. I have noticed on my images a very small scale shows the extent of the tail best.

All the best.

ps hope to have my image of last nights shoot up this evening.

[Ian Cooper]

Great stuff Luigi, Lester & Rob.

It looked like being a stunner of a night at sunset last night (16th) but bands of visible cirrus scrolled across the sky parallel to the line of the comet's tail. I could trace it well in my 10 x 50 bino's, but proximity to the LMC meant I couldn't say for sure either way if I could see it with the unaided-eye.

Did some shots with my newly acquired 450D but I had a few technical issues I hope to have the chance to remedy tonight. My widest field currently is on my old Nikon F film camera. I took a couple of 15 minute exposures on some Fuji Superia 1600 that has been sitting in the fridge since McNaught was in the sky five years ago! Checked out the film package and found out it was the official film for the FIFA World Cup in Germany, 2006! I'll do a few more tonight and then process it tomorrow. I'll keep you posted on how it all comes out.

Cheers

Coops

[Ian Cooper]

addendum to my last post, I could trace the tail for 7 degrees in my 10 x 50 bino's.

Coops

[Rob_K]

Nice shots Steve, Luis! Look forward to yours, Lester & Ian.

Anyway, here's my shot from last night, nothing much to see, my last on the comet I'm afraid:
http://i727.photobucket.com/albums/ww271/Rob_Kau/PanoramaC2011W316Jan2012textsm.jpg

Cheers -

Rob

[Lester]

Good work again Rob, to trace the tail for that length still makes it Some comet IMO.

Ian, top job on tracing the tail in the binoculars, I got not doubt that some parts of New Zealand have the best skies going around for darkness.

All the best.

ps. stacking my images from last night now, will take about 2 hours for 3 sets of FOVs.

[Ian Cooper]

Hi Lester and all,

it is a pity that the anti-cyclone over us has developed a 2nd centre because the one still out in the Tasman has dragged some useless cumulus over us now that it has cooled down. Never mind.

My mate Stephen Chadwick stacked my first lot of 6 x 5 minute exposures with my 450D from last night. I hadn't perfected the focussing, and didn't tighten up the tracking so I was hoping to correct all that tonight.

It was set on 35mm @ f/4, 1600 ISO. The negative shot shows more of the tail than I could see with the bino's.

Cheers

Coops.

[Lester]

Looks good Ian. I tried gradient mapper on this image, but didn't show as much as the inverted style. For some unknown reason DSS has had a hard time stacking my images tonight, with 2 FVOs having to be redone, at an hour each. This image below was the 2nd FOV captured last night showing the tail passing above Canopus.

3 x 4 minutes at ISO 1600 with 24mm lens at F2.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/34924def.jpg

[Lester]

Eventually got 2 FOV merged together.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/b4f68b33.jpg

[luigi]

This one looks really good Lester. Crystal clear comet. And now it's getting really difficult to image but it's a nice way to say good bye :thumbsup:

[Rob_K]

Nice job Ian, Lester! :thumbsup: Clear night tonight and I decided to give it one more go. Quite pleased with the result, appears to show the tail to around 32 degrees length. There is the vaguest hint of a continuation to the Milky Way but I think it's star alignments leading the eye in, as on the 16th. Details on pic:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W318Jan2012invertfulltextsm.jp g

Here's the normally processed version, with the tail barely visible:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W318Jan201211-34UTredsm.jpg

Cheers -

[glenc]

Thanks Rob, the tail is very faint and very long.

[Ian Cooper]

Well after having written the night off it promptly cleared. The 1600 ISO film didn't deliver the goods. I would have been better off stciking with the more recent Fuji Superia X-tra 400 which I still have plenty of.

On top of that, after spending a good amount of time getting the focussing right on my Canon 450D I maust have knocked it before my first actual comet shot because the focus had popped.

The real sucess for the night, in fact the only sucess, was the view through my 10 x 50 Nikon's. Transparency was 8/10 and meant that I could trace the tail for two bino fields, about 14 degrees in all.

I'm heading over the mountains to our annual Stardate convention this weekend and hope to have another chance to check it out from there. As well I will be catching up with everyone and chewing over comet tales for those of us who actually saw it, some of my old mates from the top half of the North Island didn't get to see Lovejoy at all, so good has been their summer!

Cheers

Coops

[colinmlegg]

Amazing deep sky images guys, kudos to you all.

Ian, maybe try taping the lens at infinity next time? I've been burnt a few times so found it's good insurance against the accidental bump.

[Ian Cooper]

Hi Colin,

thanks for that simple solution. I may get to try that over the weekend where I'm off to.

It has been a heck of a month. I just had a browse through my McNaught photo album from 5 years ago. That was a similar hectic month as well. I will have just as much pleasure sitting back on cloudy nights pouring over the pictures of Lovejoy in the future too.

Cheers

Coops

[Lester]

Hi Ian, you did well to see any of the comet in binoculars.

Here is my image from last night= 8 x 3 minute exposures at ISO 1600 with 24mm lens at F2.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/3f268019.jpg

[Rob_K]

Excellent Lester, definitely out to the Milky Way! I'll measure it soon and post a re-work.

Cheers -

[Rob_K]

OK, looks about 37 degrees as far as I can see it (use averted vision on the little inset). I'll be imaging shortly - will try a blink animation if I can come close to last night's shot.

Cheers -

[Rob_K]

Best laid plans... :mad2:

Complete stuff up with the widefield at 18mm, don't wanna talk about it. :screwy: :rolleyes: :P

Got a 'consolation' shot at 55mm, tail would extend well out of frame but it's lost in vignetting near the edge. Canon 400D, 4 x 3 min 20 sec, ISO 1600, F/4.5; 14:00, 19 Jan 2012 UT:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W319Jan201214-00UT55mmfullredinvsm.jpg

Cheers -

[glenc]

Thanks Rob for an interesting 55mm image. There is a dark ring shaped nebula above the tail. (light in the negative)

[Lester]

Hi all, had a murky sky tonight with thin cloud comming and going. This is just one exposure of 4 minutes at F2 with 24mm lens and astro 40D at ISO 1600.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/51e92277.jpg

[Rob_K]

Excellent Lester! Shows the tail right to edge of frame, about 38 degrees. I shot a bit wider, tail seems to go faintly right into the Milky Way, 39 degrees.

http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W320Jan201211-34UT18mmst6invtextsm.jpg

Sky was pretty good here but it's getting harder to image by the night. Maybe in a couple of nights time more of the tail will be revealed as it moves into a clearer patch of sky.

Cheers -

[mozzie]

i had a look for it with m scope using skysafari was unable to see it visually!!!

[Liz]

Impressive shots still Lester and Rob, well done!!

I dont know Mozzie, it had been seen in binocs a few days ago, so should be visiible in scope with a very wide angle EP????

Its funny .... usually with comets we are searching in our scopes, and find them before they become naked eye observable, but this beauty was visibible and 'BANG' ..... out there before we had a chance to drag the scope put.

[Rob_K]

Thanks Liz



Recognition with a scope would be the problem I think Liz. There's no 'head' and the pointy end's an ethereal waft of nothing. The tail broadens to a degree or two wide and you're not going to see that even with the widest field in a scope I don't think because it is too ill-defined & faint.

Binocs seem to be the only real chance. I've tried in nice dark skies and can't see anything but again it comes down to recognition I think. If you've followed the fading in binocs (like Coops has), then you know what you're looking for. Try 'cold' and I suspect you haven't got much of a chance. Use the Force, sense it, but it won't appear as a nice dim comet tail in the usual way! :P ;) :lol:

Cheers -

[Lester]

Fantastic work again Rob on recording the tail for 39 degrees. Thanks for your comments Liz.

Yes extreme wide field is the best way to record/see this large faint comet. IMO to try and see this in a telescope would be like trying to see the Horse Head.

Here is my stack of only 4x4 minute exposures with 24mm lens at F2 and Astro 40D at ISO 1600. Shows the tial with more contrast. Right side of frame is hazey due to thin cloud.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/9fb80327.jpg

[Rob_K]

Yep, the Horsehead with edges not defined! ;)

Cheers -

[mozzie]

yes i was searching for 45mins just in case skysafari was out i was using ngc1617 as a goto point then back to comet as skysafari was using
04h35m45.8s
-54deg48'15.5s
for the comets point in the sky!!!!!!!!!!
was this close or am i still aways..
as seen in your photo's it's still very large and faint,where as most comets are in the eyepiece and beautiful to see...i was just trying for one last look!!!!!!!

[mozzie]

don't start me on that rob!!!!!i going to get a good look at it this summer iv'e tried and tried (and yes i have a h/beta filter):shrug::sadeyes:

[Regulus]

Well Lovejoy did get interesting, eh?

[Rob_K]

Just a bit of rough maths from the 39-odd degrees of tail detectable on 20 Jan:

Earth was 0.984 AU from Sun, comet 'head' was 1.17 AU from Sun & 0.616 AU from Earth at the time. Using an assumption that the tail points directly away from the Sun (probably a reasonable assumption given its extreme straightness and the fact that the comet is a sungrazer), then the detectable tail length was about 1.24 AU or 185 million kilometres! It would only take an extra degree or two of tail length to become detectable over the next few days and the length would be around 200 million kilometres.

Cheers -

[Liz]

:eyepop: ... hard to comprehend, many thanks Rob. :thumbsup:

[Rob_K]

Thanks Liz. That would also mean that the furthest detectable part of the tail on 20 Jan was around 2.4 AU from the Sun, or over 360 million kilometres out. That's a long way, much further out than Mars' 1.66 AU from the Sun at the time, and almost half the current distance from the Sun to Jupiter (744 mk)!

Cheers -

[Lester]

Thanks Rob for the info on the tail length.

Here is my shot from last night, if the tail reaches the edge of the FOV it would be just over 42 degrees.

The comet is fading fast and very hard to see on the camera rear view screen.

21 exposures of varying length and ISO.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/1eb5f4d4.jpg

[tilbrook@rbe.ne]

Hi Lester.

That's really faint now!
What were the exposures you used?

Justin.

[Lester]

Hi Justin,

I used 3,4 and 5 minutes at ISO 1600, plus 12 minutes (only3) at ISO 400. Although 5 minutes bagan to show the sky fog in the dark areas it still showed more contrast in the comet's tail. So the plan is to even go longer tonight, 6,7 and 8 minutes at ISO 1600.

I want to find what is the maximum depth I can go before sky fog over powers the tail detail.

All the best.

[tilbrook@rbe.ne]

Hi lester.

Thanks for that info, I find with the 1100D ISO 3200 and 3 minutes exposure seems best for me.
But I'll try ISO 1600 and longer exposures aswell.

Thanks,

Justin.

[StephenM]

That's amazing Rob! Certainly puts the size of this thing into perspective!

Cheers,
Stephen

[Lester]

Hi all, here is last nights image, 13 x 3 minutes with 24mm lens at F1.4 and Astro 40D at ISO 1600. I would usually use F2 for better star images but need maximum sleep time due to early starts with shearing for one more day.

Comet is getting very faint, still got a long tail, but will soon be beyond my gear to record.

Tried photoshop exposure tweeking with offset and gamma correction to help bring out the tail.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/457598c7.jpg

[tilbrook@rbe.ne]

Hi, Lester.

It's a tough nut to crack now!
Tests out the camera and processing skills.
Still enjoyable challenge.

Thanks.
Justin.

[Ian Cooper]

Good to see that Lester is still dragging it in there.

Where I was over the weekend conditions weren't good enough to make any solid observations, but it cleared nicely here after astro twilight was over. I dragged out my reclining meteor observing extendable chair to lay back and Hunt for Lovejoy up near the zenith with the bino's.

Transparency was 9/10 so thought I might confirm what I thought I saw briefly last night before clouds interupted things. I am happy to say that I could still detect the first 3 degrees or so. Once I found it I went back inside and made up a chart from Megastar 5, than came out and plotted what I could see.

All I can say is that it wasn't easy. Sweeping quickly across the comet at right angles with the bino's confirmed my suspicions, but there were numerous small star groupings in line with the tail that made me think the comet was longer. In the end I dismissed those groups and came up with what is on the drawing attached. It will be interesting to see how it fits with any shots taken tonight.

What a change. A month ago I was observing Lovejoy within 10 degrees of the horizon, now it is within 10 degrees of the zenith!

Cheers

Coops

[Lester]

Top observation there Coops, to see it in binoculars now is not a feat shared by many, if any others.

Yes Justin, it does test out the processing skills, and I have no doubt that could be my limitation here.

Shooting it now in 28 degrees C at 10:30, so summer is here.

All the best.

[Lester]

Hi all,

this is 7 x 5 minute exposures with 24mm lens at F2 and astro 40D at ISO 1600. Canopus at the bottom and Sirius to the left.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/439ece91.jpg

[Rob_K]

Top stuff again Lester, with a bit of work it appears to show the tail extending extremely faintly to above Omicron2 Canis Majoris, or about 39 degrees.

Cheers -

[tilbrook@rbe.ne]

Hi, Lester.

That's a good image from last night.
I can't squeeze any more out of my camera, especially in this heat.
So it will be interesting to see if you can pull a few more rabbits out of the hat.

Cheers,

Justin.

[Ian Cooper]

Thanks Lester for providing an image from last night.

I hope that you don't mind but I took the liberty of cropping a piece around the head for comparison with my drawing. I have highlighted some groups of stars that I used to plot the comet that also appear on your image. Given the time difference between N.Z. and S.A. the fit is pretty good. If it stays clear I'll be doing another drawing plus have a go with the 20 inch to see if I can find the head with that.

Cheers

Coops

[Lester]

Thanks Rob, Justin and Coops for your comments as always. Yes the hot nights test out the DSLRs, even with the peltier running the air wasn't cool.

Your sketch is very good to compare to my image Coops. I would be interested to hear your report with the 20", and what you can see.

Rob, thanks for your continual tail measuring, I find it very interesting that the tail is still so long.

[Lester]

HI all,

the sky cleared here for just over an hour. This is 7x6 minute exposures with 24mm lens at F2 and Astro 40D at ISO 1600. Canopus to the bottom and Sirius to the left.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/8da46aea.jpg

[Ian Cooper]

Hi Lester,

no luck last night. What appeared to be a very clear sky may have had just a trace of cirrus still present after sunset. I tried observing the comet without knowing the exact position but just a general idea so that I wouldn't be baised. That didn't work, so I went in and had a look at where it should be and came back for another go with the 10 x 50's. I had a suspicion that I saw about a degree around the head, but nothing so conclusive that I would commit to putting it on paper. After nearly an hour I packed it in. Even a slight decrease in the quality of the transparency made it impossible to distinguish the comet from the background! On that basis I didn't give the 20 inch a go, maybe it would have made a difference?

That will be my last crack at it Lovejoy as the weather is putting paid to anymore attempts for nearly a week. Lester your latest shot confirms my suspicion as well as emphasising just how faint it really is now. Great effort mate.

Cheers

Coops

[Lester]

Hi Coops, yes any lack of sky transparency would make the comet a "no show". I was lucky last night as it was still cloudy here in the morning with a very brisk temperature after 2 hot days and evenings.

All the best.

[Liz]

Well done again Lester!!:thumbsup:

[Lester]

Thanks Liz. Here is tonights effort, 25th January = 13 exposures of 6 and 12 minutes with ISO 1600 and 800. Will try an individual stack of each ISO group tomorrow to see if the ISO 800 has more contrast.

For some unkown reason when I add flat frames into the stack, DSS doesn't register the bottom left area of the FOV correctly, so this image has not got any flats included.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/9661c260.jpg

[Rob_K]

Great stuff Lester! :thumbsup: Seems to show the tail fairly clearly to just past Furud (Zeta Canis Majoris), or 26 degrees. After that vague hints or nothing (see attachment).

I shot it too - lot harder to get a trace than last time I tried. Shows the same thing as yours, though not as clearly (26 degrees). Also like yours, there's a hint out further but not enough to say one way or the other.

Cheers -

[glenc]

Justin, Coops, Lester and Rob are doing a great job recording the comet's daily changes.

[Lester]

Thanks Rob and Glen for your comments. Top image again Rob, good to see. I did a seperate stack of the 1600 and 800 ISO exposures from last night and the results were no different. So double the exposure time for ISO 800 IMO isn't worth it, better to get more images at ISO 1600.

All the best.

[tilbrook@rbe.ne]

Hi,

Lester another great image!
Looks like your really having to push the exposures now.
Rob, thats amazing!
Is your camera cooled? if not even more so.

Cheers,

Justin.

[Lester]

Thanks Justin for your comments. Yes the only trick I may have up my sleeve is the 5D MK ll that has just arrived, but only a standard camera. It may be able to shoot at higher ISO with less grain than the 40D.

I think Rob uses a standard 400D, which goes to show the skill of the man.

All the best.

[Rob_K]

Thanks Glen, Lester, Justin.



Not cooled, modded or anything Justin, just the basic 400D with 18-55mm kit lens. It was quite warm last night too. I do have pretty good dark skies although last night it looked a tad milky to me so I was surprised that I got anything.

Cheers -

[tilbrook@rbe.ne]

Thanks Rob,

Thats inspired me to have another go, weather permitting.

Cheers,

Justin.

[tilbrook@rbe.ne]

Hi,

I processed a single frame from the 23rd.

1100D - 18 to 55 zoom at 21mm f/3.5 ISO 1600 240sec exp.

I'm amazed it's there!

Goes to show that I should process all potential frames, even though there doesn't appear to be anything on the image.

Gives me hope for tonight.

Cheers,

Justin.

[Lester]

Good result Justin.

Windy here from the SE and clear.

[Stefan Kurti]

Greetings from Slovakia, Europe!

I can not hardly tell anything about comet itself, but I was able to do interview with the discoverer - Terry Lovejoy.

Although some of you certainly know him personally and better, I hope there are still people to whom it might be interesting reading.

You can find it here:

http://www.skaw.sk/enlovejoy.htm


So, enjoy!

Stefan

[tilbrook@rbe.ne]

Hi,

I'm back in the game.

Here's a single image for the 26th.

Canon 1100dD
Lens 18 to 55 zoom at 18mm f/3.5 ISO 1600 300 sec.

Directly into photoshop and gradient mapping applied.

More later.

Cheers,
Justin.

[Lester]

Welcome Stefan, and excellent article on Terry, I enjoyed the read.

Good on ya Justin for squeezing the most out of your images.

I am shooting the comet now with new 5D MK ll at ISO 6400, can see the image easily on the rear view screen, so it has potential.

All the best.

[Lester]

Hi all,

been having some issues trying to stack the images in DSS from the 5D MK ll, the corners of the frame are not registered.

This is only a 4 exposure stack 90 seconds at ISO 6400 with 50mm lens at F2.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/8d2ce578.jpg

This is 12x90 second exposures with 5D and 24mm lens at F2, ISO 6400. Again DSS is having a problem with registering the whole FOV.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/6f92fc13.jpg

[Lester]

This is 4 x 150 second exposure with 5D at ISO 6400 using 24mm lens at F2. Bright meteor running parallel to the comet.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/910650bc.jpg

[CometGuy]

Excellent work Lester and Justin. The region near the head seems to still have a bit more brightness and would problably show up well with a longer lens. We have had close to 400mm of rain here last couple of days with rain/cloud on the forecast for the next week, so no chance of follow up observations here for a while :( So its great you guys are still giving it coverage.

Oh and Stefan thank you for posting the article!

Terry

[Liz]

Well done Lester, looks like the new camera is doing a great job. :thumbsup:

[Lester]

Thanks Terry and Liz.

Yes Liz I even think it may be better than the Astro 40D that can easily fog the frame if exposures are too long. The 5D didn't show any sign of fogging the frame at 150 seconds at ISO 6400. That would be equal to 600 seconds at ISO 1600, and at half that the 40D was fogging the frame.

All the best.

[Lester]

8x6 minutes exposures with Astro 40D at ISO 1600 and 24mm lens at F2.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/f5567186.jpg

[tilbrook@rbe.ne]

Hi,

Thanks Terry and Lester.

Lester the new camera seems to delivering good images, it will be nice some DSO shots from it.

Cheers,

Justin.

[Rob_K]

Fantastic work Lester & Justin! :thumbsup: Very murky sky here tonight, doesn't look like I'll be getting a shot. :sadeyes:

Lester, I 'operated' a bit on yours (26th) and it seems to show the tail pretty much into the Milky Way, or 31 degrees. The 5D seems to be working a treat!

Cheers -

[Lester]

Thanks Justin and Rob for your comments. Just waiting for my wife to get home from her pub crawl with girl friend, so she can keep an ear out for the grandchildren as they sleep.

I am keen to try even longer exposures at ISO 6400 as there was no sign of fogging the frame at 150 seconds.

All the best.

[tilbrook@rbe.ne]

Hi,

Here's my images for the 27th.

I concentrated on the head of the comet at 160mm F/L.
I went for ISO 6400, so the images are noisy, but I'm quite happy with the result. There seem to be a central bightening extending from the head of the comet.

The bright star is Alpha Cae.

Camera Canoon 1100D.

Lens 75 to 300 zoom at 160mm F/5 ISO 6200
2 x 120 sec exp plus dark frames
Processed in DSS and Photoshop.

Cheers,

Justin.

[Rob_K]

Good work Justin! :thumbsup: My skies cleared and I decided to try a close up too, at 200mm - but halfway through the first sub cloud formed and that was it. Not a trace, too short apart from the browny cloud influence. :mad2: Great to see your image to show me what I was looking for in vain. :rolleyes:

Cheers -

[Lester]

Very nice shots Justin.

This is 9x3 minute exposures with 24mm lens at F2 and 5D MK ll at ISO 6400. Still having hit and miss issues with DSS, so this is a crop of the full FOV. Will try this again later when I have time.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/83790b67.jpg

Here is 1x3 minute exposure full FOV.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/bc1761eb.jpg

[Lester]

Hi all,

This is a stack of 4x5 minute exposures with 70-200 lens at 70mm F2.8 and 5D MK ll at ISO 6400. Cropped from the full FOV.

I also took some exposures with the 24mm lens, but the contrast of the comet is very hard to pick out from the sky background. This 70mm image shows the comet better.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/bebc7da3.jpg

[luigi]

Great Job Lester. Pinpoint stars and it's still visible even at an incredible distance from our solar system. Great work! :thumbsup:

[tilbrook@rbe.ne]

Hi, Lester.

Great job once again.
It was clouded out here last night, hopefully tonight

Cheers,

Justin.

[Lester]

Thanks Luis and Justin for your comments.

Had cloud here to the east, and thought it may be over your area Justin. Don't think I will bother with the 24mm lens anymore on this comet as it doesn't give resolution at such depth to help bring out the faint comet. Just need to nail its position better so I can try the zoom lens at higher setting.

All the best.

[Lester]

Hi all,

took this image last night 29-1-12, it is 5x2.5 minute exposures with 50mm lens at F2 and 5D at ISO 6400. Unfortunately DSS doesn't want to add the Flat frames into the mix without stuffing up the stacking process.

Any tips on adding flat frames into DSS and getting good results would be appreciated.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/290f3afc.jpg

[tilbrook@rbe.ne]

Hi, Lester.

Good work to capture that.
I tried at 200mm on Sunday 29th, nothing on 6 images.
Must say, seeing wasn't the best very high humidity and the sky was hazy.

Cheers,
Justin.

[Lester]

Thanks Justin for your comments. Here is image from the 29-1-12 with less vignetting, but still some. Just used Gradient xterminator a few more times.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/cb09cec6.jpg

Tried for the "umpdeenth" time to follow how to reduce vignetting with R.Scott Ireland's book Photoshop astronomy, and acturally got it done. It isn't hard to follow, just that dure to my lack of know-how I had trouble following the procedure. Still had some vignetting around the perimeter, so cropped that out.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/090cc349.jpg

[Rob_K]

Really, REALLY pushing it now. :rolleyes: Still, sky cleared somewhat last night (30 Jan) after about an hour of cloud making right over the area I wanted to image and I did get two fields at 55mm. With a combination of Photoshop and averted imagination traces of the tail are vaguely detectable to perhaps as much as 26 degrees. A section is missing, lost in the horrendous vignetting at the junction of the frames (no flats). Here's the first field:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W330Jan2012invtextsm.jpg

Here's the panorama, FWIW:
http://i727.photobucket.com/albums/ww271/Rob_Kau/PanoramaW330Jan2012textsm.jpg

Needed more subs but it was getting too late with the tail plunging into the town 'light bubble'.

Cheers -

[Liz]

Good work fellas, and thank you. :thumbsup:

[Lester]

Top effort there Rob to get the tail recorded for such a length. I cannot remember seeing a comet this faint with a tail as long as this. Does anyone know if this is a first?

[Rob_K]

Farewell Lovejoy, that's it for me, definitely. Last shot, thanks for the memories! :lol:

Got this at a bit after 1am this morning, 1 Feb. 8 degrees or so of the tail was all I could detect after comprehensively mangling my image. For this field, the bright stars were blown out by haze in two of the three 4-min subs I took. I imaged further out in better sky conditions afterwards but 4 x 4 min subs revealed no discernable trace of the extension of the tail, unlike the 2 x 4 min subs taken the previous night (with dew forming on lens!), go figure. :shrug:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W331Jan2012text.jpg

Moon is setting too late for me from now on, but I reckon it's now past the range of my gear anyway. What a ride!! Look forward to what others can get though, still a tiny bit of life left in the comet before the Moon swamps it! ;)

Cheers -

[tilbrook@rbe.ne]

Hi Rob and Letser.

It's been a remakable journey with comet Lovejoy!
I would have never believed that it could be followed so far. It certainly allowed me to push my setup, and I'm really pleased with the results.

Thanks.

Justin.

[Lester]

Good effort Rob, the comet is really getting faint now. I still hold hopes to get it again when the cloud leaves my skies. I just hope that the comet is still high enough for me to get from within the observatory by the time the Moon sets at around 1:30 tomorrow morning.

Thanks Justin, have enjoyed your input of images also.

All the best.

[Rob_K]

I'll echo that Justin! It's been a 'joy' to follow the comet's progress and eagerly await the postings by yourself, Lester and others. Well done guys! :thumbsup: And maybe, just maybe, Lovejoy has a little life left in it yet. ;)

Cheers -

[CometGuy]

Still some steam left in the "old girl". This image was made last night (Feb 4.5 UT) in bright moonlight and is 61 x 35 second exposures with hyperstar C8 and QHY9. The image is 1.5 degrees high to give some aspect to scale. Stacking was performed in Astrometrica.

I'm not sure how much longer I'll be able to track it, but maybe as long as March.

Terry

[Lester]

That is a good image with the Moon so bright Terry. Any filters used to help reduce Moon light? Also what are the zig zaggy little chaps in your image?

I am hoping to get back at it after Full Moon.

[CometGuy]

Hi Lester,

No filters, just lots of gradient correction required. The ziggy zaggies are hotpixels that weren't corrected from the dark frame (my dark frame is getting a bit old) and the pattern is from periodic error in my drive.

Astrometrica has a nice function that allows it stack based on the motion of a minor planet, which is what I did here.

Terry

[tilbrook@rbe.ne]

Hi, Terry.

So there's still hope!
I'll have another go at your comet, that's if my new imaging setup ever arrives.

Thanks,

Justin.

[Liz]

Oh yes Justin, and what did this comet make you buy????? I wonder how many people bought new gear because of this comet - I did, as did Lester. :whistle:

Great image Terry, still pretty visible with a bit of processing. :)

[tilbrook@rbe.ne]

Hi, Liz.

Iv'e bought a pretty standard astro imaging setup.

Heq5 pro mount, 8" f/4 astrgraph with coma correcter. and orion autoguider package from BINTEL.

I wanted something portable, my homemade gear is heavy and not very portable. Also wanted a little more accuracy, drive wise.

Cheers,

Justin.

[Rob_K]

Well, I'm stunned. First chance with the Moon moving back and around 7 degrees of tail is still showing faintly:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W312Feb201211-05UTtext.jpg

Comet is the faint blue streak at the right hand side. Don't know what happened to my centering, camera might not have quite been in line with the scope. :shrug: Rapt, have been able to follow this comet photographically since 2 Dec, through all its stages. :D

Cheers -

[Lester]

Top catch Rob, I almost missed the FOV. Set the co-ordinates and just squeezed it into the 200mm FOV. This is 3x5 minute exposures with 5D MK II at ISO 6400.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/16d2d212.jpg

[Liz]

Wow guys, unbelievable!! Well done!!! :thumbsup::thumbsup:

[tilbrook@rbe.ne]

Hi, Lester and Rob.

Great work once again.
Hope to try tonight through the new scope. Polar aligned it last night, need to do PEC training tonight, and hopefully that will be enough to get some reasonable length exposures.

I'm still waiting on the auto guider package to come.

Cheers,

Justin.

[Rob_K]

Thanks Lester, Liz, Justin. Hope the new gear works out alright, look forward to the results Justin! :thumbsup: Nice catch too Lester!

Cheers -

[tilbrook@rbe.ne]

Hi,

Well I'm surprised but here it is!

Not much I know, there is a broad streak from the middle of the frame to the top.

I tried at ISO 6400, too much noise, so I stuck to 3200.

equipement.

8" f/4 reflector coma corrector ( not real impressed with this!), HEQ 5 pro mount no auto guide.

Camera canon 1100D - ISO 3200 - 5 x 5 minute exp.

Stacked in DSS and processed in photshop.

I may to improve the image if I can work out how to stack comets in DSS.

Cheers,

Justin.

[Lester]

Good to see you got it Justin. Could be hard to find at that focal length. I tried last night, only got one exposure before cloud arrived. Cannot see the comet in my FOV, the sky was very murky before the cloud.

All the best.

[Rob_K]

Congratulations Lester on your Lovejoy image from 23 Dec making it onto the front cover of the Journal of the British Astronomical Association.
http://britastro.org/journal/122-1.htm

Cheers -

[Lester]

Thanks Rob. Here is my image of Comet Lovejoy 16th February. It is 7x5 minute exposures with 5D MK II at ISO 6400 and 70-200mm lens at 200mm F2.8 .

This is a much better result than what I got two days ago with the lens at 70mm F2.8.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/ac23f18b.jpg

[Lester]

Hi all, this is 5x6 minute exposures with Astro 40D at ISO 1600 and Takahashi 160mm Epsilon Astrograph. This scope was trained by a pro for comets; before I had it.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/7a7096e5.jpg

[Liz]

Brilliant Lester, there's certainly life in the old girl yet!! :thumbsup:

[Rob_K]

Nice shooting Lester! :thumbsup: Looking good for tonight, might give it a go at 200mm as well - if I could get half what you got I'd be happy! ;)

Cheers -

[Rob_K]

I wish Lester! :rolleyes: Not much luck tonight at 200mm, only the very faintest trace of the tail, depending on what your imagination is like. :lol:
http://i727.photobucket.com/albums/ww271/Rob_Kau/C2011W317Feb2012text.jpg

Dare I say it (again!), that's it for me on this comet? ;)

Cheers -

[Lester]

I can see it with averted vision on your image Rob. This comet is over magnitude 17 now and large/diffuse, so to record it with a tail of over 4 degrees, it is still the largest southern comet in our skies. Well done Rob.

What exposure times and ISO did you use Rob?

[Rob_K]

Thanks Lester. I took it at 200mm and it was maxed-out for my camera/lens combination at ISO 1600 & F/5.6. The 5 subs represented 20 mins of painstaking hand-cranking trying to avoid the slightest tremor in the wobbly EQ1 mount, but 30 min in all because there were two wasted framing subs and two shorter subs interrupted by cloud. Never gone that long before on a target! :P

Cheers -

[CometGuy]

Well done Lester, the Epsilon records it easily!

I had a go last night but waited onto it go into my - heavily light polluted - western sky so the gradients are very bad and not worth posting here (although it is still visible).

Terry

[CometGuy]

Hi Rob,

Well done getting it at f5.6! Time for a faster lens :).

Terry

[Rob_K]

Thanks Terry - yeah, this is the time where a cheap zoom lens really lets you down. Ahhh, one day.... :lol:

Cheers -

[Lester]

Hi all, here is tonight try at comet Lovejoy= 4x8 minutes with 5D MK II at ISO 6400 ICNR on, using Takahashi 160mm F3.3 Astrograph. It is listed at magnitude 17.5 . Showing tail of 1 degree.


http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/8deb8b84.jpg

13x6 minute exp with astro 40D at ISO 1600 and 200mm F2.8 lens. There is a red cast in the top of image that I could not get rid of.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/1497c584.jpg

[pixelsaurus]

You guys rock. I long ago gave up.

[Liz]

Amazing stuff there Lester!!! :thumbsup:

[tilbrook@rbe.ne]

Hi, Lester.

Comet Lovejoy refuses to lay down!
Great work.

Cheers,

Justin.

[Lester]

Thanks Mike, Liz and Justin for your comments, as always.

[Shark Bait]

According to Starry Night, Comet Lovejoy is approx 212.5 million km from the earth and 270.8 million km from the Sun. It is still able to put on a show.

The Little Comet That Could!

Thank you for the image Lester.

[CometGuy]

Good stuff Lester, especially the astrograph image. But doesn't look there is too much left to image.

Also noticed your photo in April S+T, well done on that as well!

Terry

[Lester]

Thanks Stu and Terry for your comments.

You got the April S and T already Terry, it will take a few months to get over here. Yes it is supposed to be in the US version also and Astronomy mag.

The diameter of the Astrograph is really helping over the 77mm diameter 200mm fl lens. I think you will be able to get the last image with the hyperstar Terry.

All the best.

[Lester]

Hi all, here is last night image 22-2-12 = 12 x 4-6 minute exp with astro 40D at ISO 1600 and Takahashi astrograph. The first is a full size crop of the comet showing some distant galaxies down to magnitude 16.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/a7dd5aa0.jpg

This is a reduce size full FOV.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/2c628c03.jpg

[CometGuy]

Hey Lester I saw it online in the US copy online....see here:

http://www.nxtbook.com/nxtbooks/newtrack/st_201204/

Weather and light pollution might prevent me from further observations...so looks like its up t you Lester :)

Terry

[Lester]

Thanks for the link Terry, as I do not get the US version anymore. I appreciate it.

I have attached tonights image of your comet, it is 9x6 minute exposures with astro 40D at ISO 1600 and Tak. Astrograph. The comet has reached magnitude 18. The galaxy in front of the comet's head is PGC 16445, magnitude 16.7 .

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/2bbd2f04.jpg

[jjjnettie]

:D Holy Schmokes!! Extreme cometary imaging. !!!

[Ian Cooper]

Hi All,

it has been an amazing two months chasing the tail of this Great Comet! I am sure all of us wouldn't have believed that anyone would still be imaging the little comet that could after two months. Thanks to the sterling work of those who caught the comet bug in a big way, most notably Lester, Rob and Justin to name but a few, I was able to plot the comet as seen in photographs taken from New Zealand & Australia from my first sighting on December 19th, 2011 through to Lester's image of February 21st, 2012.

The two major gaps are due to the full moon.

I created a wide field chart from The Sky version 6. Turned it into a B&W image and sketched on the impressions of the comet from numerous contributions to this site and others, using pencil. I then inverted the image colours to produce a white on black picture.

The hardest part was deciding where the tail actually ended. This is a perennial problem for all cometary observers. I have decided that if I am uncertain then I will not show it extending beyond my certainty. The hardest section to determine was when Comet Lovejoy crossed the Milky Way.

Anyway this is just my little momento of a memorable period in comet history for you all to enjoy.

Cheers

Coops

[Lester]

Hi Coops, that is a very nice way of remembering and seeing the progress of comet Lovejoy over that period. No doubt it would have taken quite a length of time to do.

Thanks JJ for your comments also.

All the best.

[Ian Cooper]

Hi Lester,

funnily enough, given my chart scale, it was actually your last few images that were the hardest to plot due to a lack of faint stars in the area on my chart. Having said that I am happy that it is a fairly accurate representation overall.

One thing to mention for the casual viewer. It may seem like the tail had shrunken just after the full moon in January as the comet passed in front of the LMC, but this is wrong. The shorter lengths were probably due to the fact that we didn't expect the tail to still be so long at that stage and photographed accordingly. Once it was realized what we were dealing with, your good-self, Rob & Justin worked on getting the wider shots needed to show this, for which we are ever thankful!

Cheers

Coops

[Rob_K]

Fantastic job Ian, a great souvenir of a special visitor! :thumbsup:

Cheers -

[tilbrook@rbe.ne]

Hi, Ian.

That's fantastic work!!!
Do you mind if I download your sketch?
I'd like to frame it and place it on the wall.

Thanks for your efforts.

Cheers,
Justin.

[Ian Cooper]

Hi Justin,

no worries mate. It is there for everyone to use.

Cheers

Ian

[Rob_K]

Interesting point Ian, and it applies before & after January too. Earlier on the fainter end of the tail got lost in the brighter parts of the Milky Way so we don't know its full extent then. Same applied in late Jan - images showed it extending into the Milky Way but not out through to the other side out of it. Now with it being very faint we're only imaging a 'bright' part near the head, at fairly high zooms. But seeing as I got a faint trace for nearly 5 deg (to the edge of my frame) a week or so back with very limited gear then you can bet the tail is still quite long. But it takes so long now to get the necessary exposure times on the 'bright' bit you simply haven't got time to continue imaging narrow fields down the tail. :shrug:

I should add that in all the recent DSLR shots, the tail appears to end near the edge of the frames - this is a lens/camera vignetting issue, nothing to do with tail continuing or not continuing on. Doesn't matter how you frame the comet it doesn't seem to quite make it to the edge!

Cheers -

[Lester]

Hi all, got the comet last night 25-2-12, the first image is 16x6 minute exposures with astro 40D at ISO 1600 and Takahashi 160mm f3.3 Epsilon Astrograph. I hope Rob or Terry can answer the mystery with the head of the comet, as it appears disjointed. The bottom short piece is actually in the correct position for the comet head, with the longer section showing the rest of the tail to the left of SAO 15007 and SAO 150082. These exposures were taken between 9:18:55 and 10:57:35 p.m. S.A. daylight saving time.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/b639091a.jpg

Here are 25x2 minute exposures taken with 5D MK II at ISO 6400 ICNR, and 200mmf2.8 lens. The first is a full FOV showing at the top centre a Very rich blue star, this is Hinds Crimson star. Comet Lovejoy is below centre running cross ways.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/55b12b9f.jpg

Here is a full size crop of the above image, and showing similar to the Takahashi instrument, with the disjointed head. Could this rule out an artifact, as different camera and lens was used. I am new to comet characteristics, and don't know if it would be possible for such to happen, with head/tail becomming detached.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/c01d711b.jpg

[Lester]

Here are 2 croped images from the 25-2-12 with 200mm f2.8 lens, labels showing the position of Comet Lovejoy, Abell 7 and Hinds Crimson star. The inverted image also shows another nebula area to the right of Abell 7 forming a triangle with Hinds Crimson Star.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/b95725ff.jpg

inverted image
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/6bc6b3ad.jpg

[glenc]

Congratulations to Lester Barnes for his image of Comet Lovejoy in April's S&T page 79.
◀ LOVEJOY’S SURPRISE
Lester Barnes
In December 2011, Comet C/2011 W3 (Lovejoy) survived
a perihelion graze roughly 100,000 miles above
the Sun’s visible surface to become a spectacular dawn
object with a bright tail stretching more than 20°.
Details: Canon 20Da DSLR camera with 50-mm lens at
f/3.2. Total exposure was 1 minute at ISO 800. ✦

[Lester]

Thanks Glen. This weather here is a real tease, now with the Moon in the night sky and missed comet Lovejoy passing within 23 arc minutes of Abell 7. I will be still trying for the comet after Full Moon, but with it reaching mag 19 by then, there are no promises.

All the best.

[CometGuy]

I was planning to have a go for it tonight as it looks like the first clear night in a while.

Lester -->

http://www.nxtbook.com/fx/mags/lastissue.php?mp=/nxtbooks/newtrack/skytelescope

Click preview, select contents and scroll to page 78.

Terry

[Lester]

I hope you can get it Terry with the Moon up. Last time you got it the Moon was up also. If you can get it tonight I may have to pick your brains as to the trick for imaging such faint objects with the Moon in the sky.

All the best. No chance here.

[CometGuy]

No luck, there was too much cloud around. Anyway, its tough imaging such a large extended object in less than perfect skies since any gradient correction you apply can actually remove the object itself. One trick I've tried in the past with some success is to take a couple of frames offset a few degrees from the target to get a good background gradient. I might try this myself when clear skies appear again.

Terry

[Lester]

Thanks for the tip Terry, I have learnt a bit about gradient removal in the past few months with all the comet shooting and trying to extract maximum out of every image.

All the best.

[Lester]

Hi all, last night was my first attempt since the 25-2-12 at comet Lovejoy. The Moon was due to rise at 9:22 and that only gave me about 40 minutes of dark sky to shoot in. Transperancey wasn't the best with some high thin cloud around before sunset. I couldn't count my manditory 30 stars within Orion that is a good test for my area.

The image is 7x4 minute exposures with Takahashi 160mm Epsilon f3.3 Astrograph, and Canon Astro 40D camera at ISO 1600. North it up, and a red "X" is at the ephemeris position of comet Lovejoy. To its left you can see the faint smear of it. I hope Rob will add his handy work to this thread that has brought out the comet further than I was able to.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/4fefd916.jpg

Tonight looks like it may be clearer and will be a good chance to confirm it. The comet has only moved 15 arc minutes since last night which is only 1/8th FOV of the Astrograph.

All the best

[Lester]

Hi all, tonight 12-3-12 the transperancey was slightly better than last night enabling me to bring out the comet better. It even shows up on the standard (not inverted) image. The image is 15x4 minute exposures with Astrograph and astro 40D at ISO 1600. North is at 12 O clock, red "X" is at the ephemeris position and the comet is to the left of that and extends out of the FOV.

Standard image.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/19b1bdd5.jpg

inverted image.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/f16ddc2d.jpg

[CometGuy]

Real die-hard comet imagers now! Congrats Lester :)

Here is my attempt tonight, which required some very agressive gradient correction to tease the comet out of my somewhat light polluted skies. The tail is the streak that heads up to the top of the frame about a 1/3 of the way in from the right . This is a 90 x 60 second exposure with the QHY9 + Hyperstar. The remains of the comet are now 2.16 AU from the sun, its amazing we are still getting it to be honest.

Terry

[Lester]

Thanks Terry, good to see your image also. I would have no chance if I had any light pollution to deal with. The extra contrast in your image shows the tail extent well.

All the best.

[CometGuy]

...and there is just a chance we might do it all again shortly. Its possible the Comet found a few days ago in SOHO's SWAN instrument might be another Kreutz sungrazer on its way in for a March 16 perihelion! Lets wait and see :)

Terry

[luigi]

Yes, I read that and thought "here we go again". It's going to be crazy if the SWAN comet is a good as Lovejoy was. We'll see.

If Lovejoy was a small chunk from a bigger comet and then this one is another chunk and then.... oh my god... :D

[tilbrook@rbe.ne]

Hi Lester and Terry,

Wow!!

Can't believe it's still able to be imaged, What magnitude do you recon?

Cheers,

Justin.

[Lester]

Hi Justin, thanks for your comments. The ephemeris lists the magnitude at 19.3 for last night, but I have been informed that, the magnitude is only based on nucleus and corona from figures done back in December. And seeing there is no nucleus or corona the magnitude is anyones guess. Also as magnitude is based on a point source and not a diffuse object it would be hard to work out such on this.

I would be very interested to know also what the magnitude is. It is many times fainter than the Witches Head nebula.

All the best.

[Rob_K]

Awesome job Lester & Terry! :thumbsup: Incredible to think the tail is still holding together towards mid-March, and discernible at such distance. Here's a little animation I put together of Lester's images from 11 & 12 March. The tail is the horizontal darker bar at left, clearer in his image of last night compared to the night before.

Cheers -

[Lester]

Thanks for your handy work there Rob with the animation, show the comet well.

All the best.

[Rob_K]

Looking nice in LASCO C3 images now. Here's a stack of the 18 most recent LASCO C3 images. I just downloaded them from here (click "More 512 x 512" under "LASCO C3") and stacked them on the comet head in Registax.
http://sohowww.nascom.nasa.gov/data/realtime-images.html

Stacking smears out all the cosmic ray hits and other junk in each of the subs.

Some good info here:
http://sungrazer.nrl.navy.mil/index.php?p=news/SWAN-kreutz

Cheers -

[Lester]

Looks good Rob. How long is the tail now?

[Rob_K]

Latest image (09:30, 14 Mar 2012 UT) shows the tail extending faintly for total length of about 2/3 of a degree including coma. :thumbsup: C3 images a field out to 30-32 solar radii from the Sun, or diameter of 60-64 solar radii (~17 deg), depending which source you get the figures from.

Cheers -

[Liz]

Whoa Lester and Terry, amazing stuff, and great to see that awesome tail agan, thank :thumbsup:you.

[Rob_K]

New sungrazer is now in LASCO C2 field, very close to perihelion. Looks pretty impressive although the prognosis is poor! But then again...;)

Cheers -

[Lester]

Thanks Liz for your comments. Nice image there Rob of the new comet, the next few days will be interesting as to if it will survive.

Here is my image of comet Lovejoy from last night 14-3-12. It is 13x4 minute exposures with Astrograph and Astro 40D at ISO 1600. Measured the tail to be just over 1 degree in length. Almost leaving Lepus and will enter Orion in 2 days.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/aaf65543.jpg

[Rob_K]

Live score brought to you by everyone's favourite solar observatory, SOHO:

Sun: ~1900, Kreutz-group comets: 1 (Lovejoy)

"SOHO - solar images with flare"

:sadeyes:

Cheers -

[Lester]

Thanks for the update on that Rob. Bring on the next comet.

[Lester]

Hi all, here is my image from last night 16-3-12, comet Lovejoy has passed into the constellation of Orion from Lepus. This is 21x4 minute exposures with atrograph f3.3 and Astro 40D at ISO 1600. The tail is still over 1 degree in length although getting very faint for the left 2/3 of it.

http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/bd049f6e.jpg

[Lester]

Hi all, with the comet getting extrememly faint thought I would try ISO 800 instead of 1600 to see if the finer grain would help to reveal the object better. I doubled the exposure time to 8 minutes, and the results were good, with the comet only just showing up on the standard view. The inverted view is clearer, but to get any of it on the standard view shows me it is an improvement even though sky tranparency was only good and not excellent.

Image is a stack of 14x8 minute exposures with Atrograph and astro 40D.

Standard view with labels.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/ae60399d.jpg

inverted view.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/9e54f260.jpg

[CometGuy]

Hi Lester,

It really just comes down to your total exposure as to how faint you can image. Apart from that the only improvement might be lower temperature and better transparency.

Anyway, looks like I was able to get an image of the new Sungrazer comet (C/2012 E2) that appeared a few days ago. This was made very deep in twilight on March 10, using a Canon 350D + 70-200 2.8 lens set to 135mm f3.5 and combining 72 x 3.2sec ISO400 exposures. Possibly the must difficult comet observation I've ever attempted.

Terry

[Lester]

Top catch there Terry, just before it goes behind the trees. See if this one will live past the Sun.

All the best.

[mithrandir]

C/2012 E2 didn't survive Lester.
http://sungrazer.nrl.navy.mil/index.php?p=news/SWAN-kreutz

[Lester]

Hi all, tonight was the first chance I have had to try for comet Lovejoy since the 17th March. The sky was clear with good transperancey. As the comet moves further into Orion there is a lot of faint nebula which makes finding the comet impossible. I took 15x8 minute exposures with astro 40D at ISO 800 and Astrograph.
The first image has a red X at the ephemeris position of the comet.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/62f83c5e.jpg

inverted image, but still no comet.
http://i638.photobucket.com/albums/uu109/Lester_045/Comet%20images/The%20best%20of%20comet%20C%2020011 %20W3%20Lovejoy/9e903ce8.jpg

[CometGuy]

Hi Lester,

I'm glad you followed the comet as long as you did, it looks like you a problably the last. I was going to have a go last night but decided to do a comet search instead (and as you noted the starfields are getting very crowded so it would be just about impossible to find).

Terry

[Lester]

Thanks Terry it has been a good journey. I don't think any sized scope could pick it up now with the sky background full of nebulosity that is brighter than the comet.

Good luck Terry, hope you can discover another soon.

[CometGuy]

Hi Lester, had another go at capturing the comet 2 nights ago, but alas nothing. Looks like your mar 17 image is the last.

Terry

[luigi]

This is a terrific, terrific catch. It made me jump from my chair. Lucky for you it is a big chair or you would be at the end of an international lawsuit for injuries!
:D

[CometGuy]

A long awaited new paper has been released on Comet C/2011 W3 by highly respected astronomers Paul Chodas and Zdenek Sekanina:

http://arxiv.org/pdf/1203.1808.pdf

I should note that observations by a lot of people on this list appear in the paper (Lester, Rob, jjj, Justin, Trevor, etc). So congrats!

There is a huge amount of info in this paper, but if I was summarise briefly:
1. Postulated complete disruption of nucleus occured 1.6 days after perihelion as intense heat conducted into the interior of the nucleus causing it to blow apart from the inside.
2. C/2011 W3 expected to be the first of a new cluster of Sungrazers in the 21st Century. Lets hope so!
3. C/2011 W3 period ~700 years, a possible scenario for origin of comet within the Kreutz comet evolution is given.
4. Sublimation of dust near the sun caused the apparent fading of the comet and tail around perihelion.


Terry

[jjjnettie]

:) Thanks for the link Terry.
And thanks for the credit. I appreciate that.
I'll give the paper a read tonight. :)

[Rob_K]

This is the right link Terry:
http://arxiv.org/pdf/1205.5839.pdf

Thanks for the heads-up, great stuff! :thumbsup:

Cheers -

[tilbrook@rbe.ne]

Hi Terry,

Thanks for posting the link to the paper.

Cheers,

Justin.

[Rob_K]

Funny how hindsight changes things. As the comet faded off in Jan-Feb-Mar, it took heavier & heavier processing to reveal anything. Now, looking back, there's a lot more to be got from the shots when the comet was bright.

This one for instance, from 26 Dec 2011 (morning of 27 Dec our time). At the time, my report was that this shot showed 33 deg of tail and that 26 deg was visible visually. With a bit more juice, 38 deg is clearly showing in the shot. Not only that, "greater than 38-deg" would be a better estimate because the tail gets cut off pretty abruptly by vignetting on the edge of the top frame.
http://i727.photobucket.com/albums/ww271/Rob_Kau/Panoramaw355mm27dec2011inv.jpg

Here's the 'normal' version of the 4-frame stitch, each 3 x 2 min with Canon 400D at 55mm (incidentally, just got around to stitching these!). Note the band of green airglow above the horizon:
http://i727.photobucket.com/albums/ww271/Rob_Kau/Panoramaw355mm27dec2011lgecrasm.jpg

And here's a mangled positive version: :rolleyes: :lol:
http://i727.photobucket.com/albums/ww271/Rob_Kau/Panoramaw355mm27dec2011deep.jpg

Cheers -

[CometGuy]

Wow that is impressive..thanks for posting Rob!

[gaa_ian]

Great Shot Rob, I am so hoping for another comet like this.
I dragged my partner up in the early hrs for a look at this around Xmas and boy was it worth it !

[davidseargent]

Just letting you know that I have placed an article on sungrazers at www.david-seargent.simplesite.com (http://www.david-seargent.simplesite.com). If my speculations are not too wild, there would seem to be a chance that a second "Lovejoy-size" Kreutz may come along in the not-too-distant future!
David

[Rob_K]

Nice article David, let's keep our fingers crossed! :thumbsup:

Definitely worth a link to your Kindle e-book too, "Sungrazing Comets - Snowballs in the Furnace", a fantastic read for anyone interested in sungrazers and their history:
http://www.amazon.com/SUNGRAZING-COMETS-Snowballs-Furnace-ebook/dp/B00A9BY5AQ

Cheers -

[davidseargent]

Just having a look at Terry's image of 2012 E2. Interesting that it appears a bluish-green colour, probably indicating that it was then mostly the usual cometary gases rather than dust or Na emission. That ties up with the fact that this has been the only Kreutz imaged in SWAN and also supports my thought that it was a very icy fragment from deep within the broken parent fragment. If I identified the background stars correctly, I would very roughly estimate the brightness to have been about mag. 7 - 7.5 at the time. If it was around 9 at discovery, the H10 should have been approximately 12. At that time, it was probably at least as bright as Lovejoy, yet must have been a far smaller object as it seems to have peaked at no more than +1 and did not make it to perihelion. That also supports the suggestion that this was a very icy object whereas Lovejoy was largely covered by an insulating crust (at least, the portion turned toward the Sun pre-T was).
Cheers
David
(PS. Thanks for your kind words Rob ... and for your plug for my Kindle book!)

[Liz]

What a little beauty!! :cool:

This is an easy target in binoculars, so if you havent spotted it, then give it a go over the following mornings while there is no Moon.

It has been close to M44 in Cancer but is moving SE, and brightening.

Image from this am, Canon on tripod only, at 70mm, ISO 4000 for 25 sec or so.

[glenc]

The Other Great Morning Comet
While Comet ISON is brightening rapidly, Comet Lovejoy (C/2013 R1) is far more impressive right now in the pre-dawn sky.
http://www.skyandtelescope.com/community/skyblog/observingblog/The-Other-Great-Morning-Comet-231157211.html

The Guide9 map below shows Comet Lovejoy's position tomorrow 10 Nov, at 4am AEDT and its path till the 20th.
It will be 6.6 degrees from M44 tomorrow.

[glenc]

I just had a look at Comet Lovejoy. Picked it up easily with 12x60 binoculars.
The comet's tail was about 30' long when looking through a 16" Dob using a 21mm EP.

[astroron]

Glen, your observation concurs with my observation 10/11/13
see here (http://www.iceinspace.com.au/forum/showthread.php?t=114232)
Cheers:thumbsup:

[davidseargent]

I have just added a few more speculative thoughts to my sungrazer blog at www.david-seargent.simplesite.com (http://www.david-seargent.simplesite.com) that might be of interest to the sungrazer enthusiasts out there. Not quite as optimistic about a second 2011 W3-type comet in the near future as I was earlier (maybe the "second" one was SWAN after all?), but I would be very happy to be proven wrong VERY soon!
Cheers anmd clear skies.
David

[CometGuy]

Hi David, I hope there are more fragments on the way. Something Ikeya-Seki sized in December or January would be good! Well done regarding the website, I will have a good read later :)

Clear Skies,
Terry