Another Comet Lovejoy!?

[Outbackmanyep]

Hey Guys,
I been getting reports that Terry Lovejoy has found another comet, i dunno if theres an IAU circular yet but well done Terry if this true!

Cheers!

[Outbackmanyep]

New Discovery!: T. Lovejoy (Thornlands, Queensland, Australia) reports his discovery of a new comet on May 26, in the course of his survey with a DSLR (200-mm f/2.8). The 13m comet was confirmed by J. Drummond (Gisborne, New Zealand) and R. H. McNaught (Siding Spring). No orbit is yet available for comet 2007 K5. Additional accurate astrometry is needed. The comet is close to the sun and a southern hemisphere object. Preliminary orbital calculations indicate that the comet may have already passed perihelion and that its visibility condition will not improve greatly. This is the second amateur comet discovery of 2007, after C/2007 E2 (Lovejoy). Search ephemerides can be generated at the NEO Confirmation Page. (IAUC 8840, subscription required)

Well done Terry! Woohoo!

[Ric]

I was just reading that as well on the Comet Hunters forum.

Well done Terry, you must be really chuffed.

Cheers

[iceman (Mike)]

Sorry I didn't see this, just posted myself in the astronomy science forum.

Excellent work Terry!

[CometGuy]

Thanks guys, this is from the comets-ml list:

Discovery of Comet C/2007K5

After a discovering Comet C/2007 E2 on March 15 this year, I am happy to report finding another Comet just 2 months later! Naturally I am elated, especially since this one was a much tougher and challenging find, proving my techniques are working.

This particular comet (designated C/2007K5) was found as a small faint but still rather obvious blue-green haze in my images from the evening of May 26. My initial estimate is mag 13, but I admit I have not attempted more precise photometry and visually the comet could well be brighter. Interestingly the discovery was made during a bright waxing moon and in the evening sky where moderate light pollution prevails. On the evening I had both cameras (a Canon 300D + Canon 350D) mounted the usual way with the 300D pointed towards -18 declination and the 350D pointed towards declination -11. This allows me to image 13 degree wide sweep of sky from west to east. Some 12 individual starfields were covered with both cameras, with 12 subexposures of 90 seconds for each starfield.

The following day, I downloaded the images from my 300D and ran them through the usual automated processing steps (IRIS is used for this). This processing step outputs 2 images per starfield effectively separated by 10 minutes so that moving objects like comets can be identified. By 'blinking' the 2 images one can see objects like asteroids and comets bobbing backwards and forwards. On examining the first image I almost immediately noticed a moving small hazy object with a distinctive blue green colour typical of many comets. I knew I had something for sure, and notified a number of other for confirmation of a possible comet.

Confirmation came on May 28 when both John Drummond and I made followup observations, which were then sent to Dan Green at CBAT. Further followup was obtained on May 29 by Rob McNaught before an official circular (IAUC 8840) announced the new comet as C/2007 K5. Interesting, C/2007 K5 required less than 20 hours of actual searching in contrast to the estimated 1400 hours for C/2007 E2.

The comet itself appears to be quite faint, and will problably remain that way, but a comet none-the-less. Further astrometry is require to calculate an orbit and once this is done the comet will be named.

Terry

[Outbackmanyep]

You make it sound so easy Terry! Hehe
Congrats once again!

Are you going to CWAS Astrofest this year??

[bkm2304 (Richard Brown)]

Well done, Terry! Amazing how things fall into place once you get a start - 1400 hours to number 1 then a mere blink of an eye to number 2!

Richard

[Fomalhaut]

Congratulations Terry, its really awesome to discover 2 Comets in this short time period ! ! !

[circumpolar (Matt)]

Originally Posted by Ric

I was just reading that as well on the Comet Hunters forum.

Could someone please tell me where to find this Comet Hunters Forum.

[fringe_dweller]

thats Comets and Comet Hunters for ya - full of surprises! your on fire Terry! always on the cutting edge too! seriously very impressive, but i think I know or at least can guess how much hard work lead you up to this point - a shipload!

[fringe_dweller]

Originally Posted by circumpolar

Could someone please tell me where to find this Comet Hunters Forum.

here mate, http://tech.groups.yahoo.com/group/Comet_Hunters/

but bear in mind its really is for serious comet hunters only, at least i think so, no mucking around please hehe
I'm an original member, but only coz one of the owners is/was a film fan, and liked our machholz/pleides shot from another group and it graced the front page for about 2 years (as don machholz is the co-owner) and i had to be a member if my pic was there great group tho, some very familiar names there you'll see

[gaa_ian (Ian)]

Well done Terry ... you have pulled another rabbit out of the hat !

[higginsdj]

Hi Terry,

Congrats - 2 in 1 year by an amateur hasn't been done in a very, very long time as far as I am aware.

Reading your procedures I am wondering if it can't be tweaked to make it more efficient. When you say 12 fields with 12 subfields at 90 seconds each how are these used. Obviously you need at least 2 images per field to blink so at 12 fields, does this mean you stack 6 x 90 seconds per field to get 2 images to blink per field?

Given that this is 144 images at 90 seconds you obviously don't image all night so you are missing a big window. Is there a reason you don't patrol all night or is your 'automation' still in need of human intevention.

Cheers

Originally Posted by CometGuy

This particular comet (designated C/2007K5) was found as a small faint but still rather obvious blue-green haze in my images from the evening of May 26. My initial estimate is mag 13, but I admit I have not attempted more precise photometry and visually the comet could well be brighter. Interestingly the discovery was made during a bright waxing moon and in the evening sky where moderate light pollution prevails. On the evening I had both cameras (a Canon 300D + Canon 350D) mounted the usual way with the 300D pointed towards -18 declination and the 350D pointed towards declination -11. This allows me to image 13 degree wide sweep of sky from west to east. Some 12 individual starfields were covered with both cameras, with 12 subexposures of 90 seconds for each starfield.

The following day, I downloaded the images from my 300D and ran them through the usual automated processing steps (IRIS is used for this). This processing step outputs 2 images per starfield effectively separated by 10 minutes so that moving objects like comets can be identified. By 'blinking' the 2 images one can see objects like asteroids and comets bobbing backwards and forwards. On examining the first image I almost immediately noticed a moving small hazy object with a distinctive blue green colour typical of many comets. I knew I had something for sure, and notified a number of other for confirmation of a possible comet.

[jjjnettie (Jeanette)]

Congratulations Terry.
I wonder how long before you nab your next one?

[CometGuy]

Hi David,

Actually, there are lots of things I that can be done to make things more efficient . I've got quite a few enhancements on the way, a major advancement for me is finally acquiring a GOTO mount. At the moment I can only slew in RA, and have to set the startpoint manually although the slewing and camera operation happens automatically.

You are right I create 2 processed images from 6 x 90 second stacks. To answer your question about searching all night the are 2 points to consider 1) how much data can you search practically 2) Whether searching areas well away from the sun are profitable. If I were to search through the night this would lead to about 70 odd search fields, which at the moment would take the entire next day to process and the next day after to search! Remember with a DSLR you end up with very large image files. The other point is that once you venture past 60 degrees solar elongation you are competing against the big professional surveys so chances of success a quite a bit less. IMO the area of sky an amateur should concentrate on is in the region 35-70 degrees from the sun.

Terry

[higginsdj]

Originally Posted by CometGuy

The other point is that once you venture past 60 degrees solar elongation you are competing against the big professional surveys so chances of success a quite a bit less. IMO the area of sky an amateur should concentrate on is in the region 35-70 degrees from the sun.

Yes - but they publish the fields that they cover and a quick look at the weather radar will tell if they (SSS) can see anything that night! Obviously this is where automation will help as you can adjust your observign on the fly.

I'm a little concerned that it would take you all day to calibrate and combine your images - have you tried something like Astrometrica? Do you combine your images into FITs format? (Astromatrica has a womderful track, stack and blink facility as well as an overlay to identify all moving objects currently held int eh MPCORB.dat file from the MPC). Even though my images are 1.6mp each in size I can process 100 in under 20 minutes.

Cheers

PS - I'm thinking about buying an EOS 400D, hooking it up to my 4" SCT at f/6.3 and piggy back on my 14" for the occassional 'survey'. That setup would give me 1d x 2d field and it would be interesting to know how deep it could go inside say 4 minutes. Each field would be 6 minutes (including slew and settle) so thats 5d x 2d per hour (given 2 images per field per hour)......

[CometGuy]

Hi Dave,

Keep in mind I am talking about processing 800 odd 40 MB images (I keep colour data as it helps identify comets).

Terry

[CometGuy]

An interesting read:

http://homepage3.nifty.com/cometsm/C...et_hunter3.pdf

[Greg Bryant]

David,

The last time an amateur discovered two comets so close together was when the late Yuji Hyakutake discovered his first comet, C/1995 Y1 (Hyakutake) in late December 1995. Less than 5 weeks later, at the end of January 1996, he found C/1996 B2 (Hyakutake) - famed for its spectacular appearance.

It's great to see Terry's work paying off. Terry's written an article on his March comet discovery, which is appearing in the Jul/Aug issue of Australian Sky & Telescope magazine.

When news came through of this new discovery earlier this week, the day we went to print with the Jul/Aug issue, I just had time to mention it in my Editorial.

Congratulations Terry!

[higginsdj]

Originally Posted by CometGuy

Hi Dave,

Keep in mind I am talking about processing 800 odd 40 MB images (I keep colour data as it helps identify comets).

Terry

I guess storing them might be a problem as well :-)

Cheers