Comet C/2007 N3 (Lulin)

[martinastro]

Guys, I really enjoyed reading all those great observing reports and images from last night. It's great to see such a wealth of success with this comet. Brian, that's a great image you got. Carl, looking forward to your image, I hope you get it clear to capture both Lulin and Saturn which should be a cracker for the collection  . Had a great night with the comet also. Sleep deprivation is really getting to me now but to quote a line from the movie 'Roadhouse'....''I'll get all the sleep I need when I'm dead''. This is copied from my site...



The night of February 19/20th 2009 provided me with my best view of C/2007 N3 Lulin to date, simply because it stayed clear for much of the night. I was actually observing this comet on and off at regular intervals for six hours and by the time the session ended before dawn I was well and truly ready for a warm bed. The night was clear, dark, and calm. However, the most horrible frost in a long time stayed with me throughout the night and made observing not only challenging but extremely uncomfortable. Despite being suitably clothed I was physically shivering to the extent that my hands and legs moved up and down on their own. I could see the comet rise above the horizon murk during the late evening but the best view took place between 00.00 and 01.30 UT. At that time I was chatting over the phone with local astronomer John McConnell and together we observed the comet from our own back gardens at the same time which was fantastic because we could confirm what we were seeing, and exchange our thoughts and impressions of the comet at the same time. It's great to be able to share a bright comet with someone else who is just as fascinated by these visitors as much as I am.

I was using 10x50mm binos and had the camera set-up. John had done likewise so we observed and photographed the comet at our leisure while occasionally remarking on other things like Saturn and any Iridium flares or meteors which briefly interrupted the serenity of the sky. The real highlight came when we both observed Lulin at the same time quite easily with the naked eye!. Even while casting a casual glance with the dark adapted eye towards Virgo you could see a large fuzzy patch of light below the naked eye star Porrima. The comet was a few degrees to the S of this star and shared this relatively blank area with a few others stars near the limit of vision. I could detect a subtle green colour and even the central condensation (CC) without optical aid. We could even see the comet with direct vision with ease. In the binoculars the coma was a beautiful object sporting a strange and vibrant green colour with a glorious white CC which looked like a bright star. It was difficult to describe the silent beauty of that glorious comet perched against a background of dark sky complimented by a scattering of stars. With the binos shaking in my shivering hands other features soon popped into view. A long faint ion tail and a much brighter anti-tail which took up a large portion of the 5 degree FOV. Based on the naked eye view I would estimate the comet at mag +5.3, however I'm being conservative because I still feel it could be brighter than this.

Later, during the coldest period of the night I could see the comet sitting proudly on the meridian and at it's highest point in the sky directly S. Lulin, Spica, Saturn, and the Beehive cluster made for a splendid naked eye sight. I then turned the 8.5" F/7 reflector on the comet and observed for a long time. This was when I noted that aperture effect was really playing a large role on the visual profile of this comet. In the SWA 32mm eyepiece the ion tail was extremely faint, really just a stump of faint grey light which I could only detect extending for 25' in the scope. I was convinced that after a recent disconnection event that I was actually witnessing a new ion tail unfurling from the coma to replace the old one which was probably some distance 'down wind'. The anti-tail however was much brighter with a well defined edge and seemed more substantial in profile. I could track it for at least 1 degree before it blended in with the sky. The coma was a huge elliptical fuzzy patch enveloping an intense CC with a bright star-like false nucleus which was very easy to see. The above sketch made at 04.36 UT shows the view in the eyepiece at that time. Eventually the bitter temp and recent lack of sleep took their tole so I decided to end the session at 05.30 UT. It was a great night, and currently my best memory of comet Lulin to date.

[Roman White]

Great report, Martin!  I don't trust that you had bitter frosts there in N.Ireland, but an all-night session (ok, maybe half-night) is a hard work...

Sleep deprivation is really getting to me now but to quote a line from the movie 'Roadhouse'....''I'll get all the sleep I need when I'm dead''.

One part of me is very happy that 5 overcast days will follow since tonight. Sleeping only 4-5 hours on each day wasn't much good for me.

[rjgjr]

Great images and report Martin. Still haven't had the pleasure of viewing Lulin as of yet, and it doesn't look good for the next week. Great work on your part.

[Roman White]

Gennadiy Borisov keeps on posting images to Astronomy.ru forum, and it is impossible to me not to post the links...
http://www.astronomy.ru/forum/index.php?action=dlattach;topic=29295.0;attach=168847;image
http://www.astronomy.ru/forum/index.php?action=dlattach;topic=29295.0;attach=168851;image
just tell me that the tails could get better

[brianb]

just tell me that the tails could get better

Ah, now, that first one shows about what I could "see" in bins last night, but much more clearly - I was sure there were multiple ion tails but I could not see them by direct vision, sweeping across where the tails should be gave an impression. I did hope that my images might show something but I obviously need a darker / more transparent sky.

[martinastro]

Thanks for posting those links Roman. The images are amazing and they make me feel easier because the first one matches what I saw through the binos too, the second matches the scope view.

Check out page 9 of the SW.com gallery...

http://www.spaceweather.com/comets/gallery_lulin_page9.htm

Thanks for the comments guys about the report. Just woke up after a much needed cat nap  . Richard, I hope the weather is kind to you soon. Lulin would look great captured above those tall trees in Oregon!

[JohnC]

Well, I have to get out with my 10-22 (Jessops have my 28mm f2.8 under guarantee ,won't focus at infinity). I've been looking at the settings on various photos and wonder if with Dennis's photo, 20 secs. at ISO 1600 is too long re. noise/pixelation - I see Paul's 0430 photo on the last page  too, also has 1600 ISO   but half the time and no noise. Brian's got 800ISO. also 10 secs. I would try different  shutter times  and maybe ISO's but I wouldn't see the result in the LCD I wouldn't think.
Is ISO  1600 at 20 secs. too long ?

[Tyler]

depends on your light pollution John.

I made observation #4 last night in a nasty wind, only observed it for a few minutes, I did note that it IS now visible with my binoculars. did get a few images, but they turned out bad. Lets all hope we have clear skies on the 24th!

[Carl O Beirnes]

Hi Lads,

Well the weather did it again I waited up till 5 this morning  I could not get a glimpse of the comet. Weather is looking bad for tonight too.

Carl.

[JohnC]

Cheers Tyler.  We have clear skies atm but not tomorrow/monday. Just look at this lot en-route.

http://www.metoffice.gov.uk/satpics/latest_VIS.html

[John9929]

Well, better late than never! I was delayed somewhat in uploading this image taken at 02:33UT on the 20th because of an interesting fact uncovered by comet expert Gary W Kronk. On this same morning he was imaging Lulin from his home in Illinois, United States but exactly seven hours after my image was taken. He discovered that the coma of the comet passed directly over the asteroid 29 Amphitrite at mag 9.9. Gary actually marked the asteroid on my image below which is a crop from a wider field. Camera was clock driven and the exposure was 48 seconds at f3.2 50mm 1.8 lens. Late last night I found a further twist, 29 Amphitrite was the only asteroid discovered by Albert Marth, a German astronomer who at one time worked at Markree Castle Observatory in Co.Sligo! The asteroid was discovered on March 1st 1854 when he was working at George Bishop's observatory in London, interesting or not!

[brianb]

Late last night I found a further twist, 29 Amphitrite was the only asteroid discovered by Albert Marth, a German astronomer who at one time worked at Markree Castle Observatory in Co.Sligo! The asteroid was discovered on March 1st 1854 when he was working at George Bishop's observatory in London, interesting or not!

Very interesting .... I see it's on my image too (ten times!) Obviously it just looks like any one of a zillion other mag 10 stars.

[John9929]

I see it's on my image too (ten times!)

I see that Brian.........pity you didn't know that at the time though!

[martinastro]

Nice one John!!. An asteroid and comet on the same image is really something special. 

[martinastro]

Seen comet Lulin again last night through gaps in the cloud with the naked eye without using optical aid first. It looked very bright with an obvious green colour and condensation. It was located extremely close to a bright star which looked to have been within the coma itself. Comet looks near mag +5.0 to me. Sky was incredible, clean, and BLACK. Best I've seen in a long time. Unfortuntately it never cleared after this for the rest of night.