Here's a challenge for all you visual comet observers and astrophotographers. 2007 F1 (LONEOS) has now been picked up in the northern hemisphere by Michael Jaeger and Gerald Rehman via CCD who estimate the comet at magnitude + 11.0 making it currently 1 magnitude brighter than expected. On Sunday October 28th it will reach perihelion at 0.4 AU from the Sun when it is expected to reach magnitude 6 but with the recent estimate by Jaeger and Rehman this could very well be a magnitude 5 comet not taking in account any unexpected outbursts. This will be an attractive target for observers and imagers who might witness quite a nice comet with tail. The problem is that the comet stays very low first in the evening then pre dawn sky near the horizon and stays at a low elongation from the Sun. I advise plotting the RA and DEC positons onto a star atlas or using starrynight pro to watch its position each evening so an observing session can be planned.

This comet should be visible in binoculars and small telescopes. The challenge is not only to find the comet but..who will be the first to catch it in the UK? Do post any visual observations, sketches or images on this thread.

2007 F1 (LONEOS) was discovered as a 19th magnitude asteroidal object by LONEOS on March 19.26 with the 0.59m Schmidt, and posted on the NEOCP has been shown to have cometary characteristics by many observers including Peter Birtwhistle and Giovanni Sostero et al. Brian Marsden notes on MPEC 2007-K76 [2007 May 31] that The "original" and "future" barycentric values of 1/a are +0.000679 and -0.000184 (+/- 0.000075) AU^-1, respectively. The large "original" value suggests that this comet has made a previous visit to the inner solar system.

Chart

Monthly evening, morning positons of F1...

http://www.aerith.net/comet/future-n.html

Ephemeris...

http://www.ast.cam.ac.uk/~jds/07f1.uk

Happy hunting!

This comet is brightening fast!...

C/2007 F1 (LONEOS):
2007 Sep. 20.20 UT: m1=9.3, Dia.=2.5', DC=5, 20 cm SCT (77x).
[ Mountain location, very clear sky, astronomical twilight; Altitude:
6 deg ].

( Alto del Castro - Aralla, alt. 1720 m, Leon, North Spain )

Best regards,

J. J. Gonzalez

Comet now mag 8.5 low in the NE morning twilight. It could reach mag + 4.0 in mid October. Make sure you try for it!

Here's a good finder chart from skyhound...

http://www.cometchasing.skyhound.com/comets/2007_F1.gif 

Comet 2007 F1 (LONEOS) is visible in the early morning from favourable locations, and is roughly a magnitude brighter than was expected. The comet should reach easy binocular visibility in October. It will be a northern hemisphere object prior to perihelion and is now visible from UK latitudes.

Image by Gerard Rhemann and Michael Jager

Have just updated my site about this comet...

http://www.nightskyhunter.com/Sky%20Events%20Now.html

Thanks Andy. Always like to provide people with a 'heads up' on any bright comets. I haven't seen it yet due to poor sky conditions but I will be trying tonight before dawn if it stays clear.

Best of luck.

Well I reckon I might have it in my 16x50's.  I've got a faint point of light (can't confirm any coma yet) smack where the comet's meant to be, and judging by the finder chart linked on Martin's site the other stars in that little region aren't too bright: +8.4.  I Could see a star of +7.1 reasonably easy over in the near by Coma star cluster though so it's not crazy that it might have been the +8.4 star.

Having trouble with low cloud and binocular shake (to much tea and coffee?) so hopefully in the coming days I can get a look when it's darker.  Probably not later tonight as we're having someone round for dinner.

Andy that sounds like a very encouraging observation...if you seen it (and can confirm it) then this is the first obsv from the UK. I would send any future observations to the BAA!

I have been soo clouded out lately. Never got a chance for the comet and the major aurora activity was missed also.

Keep up the great work.

We shall see!  Was hoping for a chance this morning as I was out but it clouded over not long after 4am.  I think it's going to be possibly impossible to get my scope on this comet, which is a shame, and I might make an excursion to a field to have another go as I look like a peeping Tom standing out on the road with my binoculars aimed low.  Good hunting!

Quick sketch

Seen it again tonight through a small clear gap in a slow moving section of Alto Cumulus which covered the western sky. I picked up the comet at 21.16 BST when it was only some 5 degrees above the NW horizon in a hazy sky with poor trans. It shared the same telescopic field with treetops. It set after 5 min's of observation. The coma looked bright, compact, moderately condensed (DC: 6), brighter toward the centre with a stellar false nucleus which was easier to see tonight. No tail. Coma was a grey-green tone and I thought it looked larger tonight in the 3.5 - 4' range. Looked nice within the heart of open cluster Melotte 111. I thought I glimpsed it in 10x50s.

My friend Paul Evans from N. Ireland managed to get an image of the comet tonight...

Before dawn (Oct 4/5th) I made my 2nd visual observation of C/2007 F1 LONEOS within 12 hours. In the pre dawn sky it was well placed in the NE within Melotte 111 in Coma Berenices. I observed it from 05.30 - 06.08 BST with the 8.5" F/7 reflector. I noticed that the pre dawn period is much more favourable than the corresponding evening apparition with the comet clearing rooftops at the beginning of the session greater than 10 degrees in latitude. By the end of session the comet was between 15 - 20 degrees high. For much of the session it was visible in a dark sky!

Coma was grey-green with white central region sporting a vivid stellar false nucleus. Coma is compact and well condensed. I also made my first observation of a blue plasma tail extending for no less than 1 degree to the north even in light haze. At one stage I suspected the tail was greater than 2 degrees long however I cannot confirm this. Comet is looking very healthy! Mag: + 7.5 D.C:6 Dia: 4' - not seen in 10x50s.

Sketch

Image

Nice work Martin.  I've just been out with my 16x50's again but can't get a good look due to thin cloud.  Can't get my scope on it either due to altitude, grr!