Comets C/2012 F6 (Lemmon) and C/2012 K5 (LINEAR)

[starfinder]

There are two minor comets which are active now, C/2012 F6 (Lemmon) and C/2012 K5 (LINEAR).

Comet C/2012 F6 (Lemmon) is now in Hydra (in the southeast around 3am these days from Singapore) at around mag 9. Its perihelion (closest passage from the Sun) will be on 24 March 2013 at 0.74 AU, and will be closest to Earth on 5 Feb 2013 (I think) at 0.985 AU. It *could* reach a relatively bright mag 3 around perihelion, but I don't think it would be visible from Singapore around that time.
More info here:
http://www.aerith.net/comet/weekly/current.html
http://www.aerith.net/comet/catalog/2012F6/2012F6.html
and:
http://tech.groups.yahoo.com/group/come ... sage/20253
http://www.ast.cam.ac.uk/~jds/coms12.htm#12F6

The other comet, C/2012 K5 (LINEAR) is now in Lynx (in the northern skies near midnight now) also at around mag 9. It had its perihelion on 28 Nov 2012, and will be closest to Earth on 31 Dec 2012. It's around its brightest now.
More info here:
http://www.aerith.net/comet/weekly/current.html
http://www.aerith.net/comet/catalog/2012K5/2012K5.html
and:
http://www.ast.cam.ac.uk/~jds/coms12.htm#12K5

I managed to image both comets from here in Singapore in the last 2 days. However, I did not get an opportunity to try to observe them visually in the eyepiece of my scope as it became cloudy after I imaged them. I doubt they would be visible in the eyepiece from Singapore as they are quite faint at around mag 9, but will try again soon.

Here are the images. Note that each image has been resized differently.

Of course, these two comets are the appetiser for what we hope would be the two great comets of 2013, Panstarrs and ISON.

[Gary]

Nice attempts! Congrats!

[Airconvent]

Hi Gavin
Your faithful workhorse the LX90 really is giving you your money's worth! Looks like you are Singapore's answer to Charles Messier!

[starfinder]

Hi Gary, thanks!
Hi Rich, thanks! Yup, my trusty LX-90 will turn 12 next month. It's a great piece of engineering!

Here is a .gif animation of Comet C/2012 K5 (LINEAR) which I have made. After taking the first 2 images that morning (29 Dec in Singapore), I was surprised to see that the comet had moved in less than a minute. I therefore continued to take several more frames. The .gif animation is made out of 7 frames taken over 15 minutes.

I calcuated that the comet was having a proper motion of about 0.22 degrees (or 13 arc minutes) per hour. The comet is currently making a rocket speed leap from the northern skies due south. This can be seen from the movable orbit diagram on the following JPL website (JPL Small-Body Database Browser):
http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=C ... ;cad=0#orb
As it is a Java applet, it might not run on some tablets or mobile devices.
(For other comets, you could do a search on the object's name on following webpage: http://ssd.jpl.nasa.gov/sbdb.cgi and then click on the option for Orbit Diagram.)

Here is the .gif animation. I used the very good freeware called PhotoScape to make it. The frames have been compressed to save space. Likewise, it might not run on the browsers of some mobile devices (try saving the file and running it on different apps).

http://img15.picoodle.com/i5ct/starfind ... _u8s7b.gif

[Airconvent]

Thanks for sharing again Gavin..
12 years eh? I think in our 20 years time, you will be like Mr Au and his Ultima 2000, expounding how good your old classic LX90 is with great pride!
Do keep it running and let us know any more updates on the comets.

[starfinder]

I have this evening managed to view Comet C/2012 K5 (LINEAR) in the eyepiece of my LX-90 (8" SCT) from here in Singapore city. I used a Pentax 14mm XL eyepiece for 143x. The comet was in Auriga at RA 06h 13m 28s and Dec. 43d 15m 43s (J2000) at 10:05pm local time (1405UTC) on 1 Jan 2013.

Just prior to viewing it, I had imaged the comet over 20 mins and the images clearly showed a small fuzzy round object (comet) which had moved quite noticeably.

In the eyepiece, the comet was very faint but could be seen with direct vision with a little effort. With averted vision, a small brighter pin-point core could be seen surrounded by the fainter fuzz. I compared the size of the comet's coma with nearby Jupiter; what I saw of the entire coma appeared to be slightly smaller than Jupiter (then 46 arc seconds). No tail could be seen. The comet was plain white/grey.

Over 20 mins, the object in the eyepiece had clearly moved in the eyepiece as compared with surrounding stars. What I saw corresponded exactly with the chart on Sky Safari Plus .

The comet had its closest approach to Earth yesterday (31 Dec) at 0.29 AU.

There! I'm glad to have been proven wrong about not being able to view the comet from central Singapore. It's reported elsewhere to be around mag 8.3 now, e.g:
http://tech.groups.yahoo.com/group/Come ... ssage/4877

[cataclysm]

Always amazed with your works Gavin!

[Gary]

Awesome comet time-lapse video captured using mass-produced amateur-class telescopes. Comet C/2012 K5 (LINEAR).