British Astronomical Association
&
Society for Popular Astronomy
Comet Section

Current comet magnitudes (January 25) and observable region (January 29)

Comet	                  Magnitude   Trend    Observable     When visible
Garradd (2009 P1)              7      steady   90 N to 10 S   early evening + morning
21P/Giacobini-Zinner           9      bright   50 N to 25 N   early evening
Hill (2010 G2)                10      fade     70 N to 55 S   evening
49P/Arend-Rigaux              10      fade     90 N to 50 S   best morning
Gibbs (2011 A3)               10.5    fade     Conjunction
P/SOHO (2012 A3)              11      steady   15 N to  5 N   early evening   
78P/Gehrels                   11      steady   75 N to 45 S   evening
45P/Honda-Mrkos-Pajdusakova   11      fade     60 N to 50 S   morning
SWAN (2011 Q4)                11.5    fade     90 N to 25 S   best morning
McNaught (2011 Q2)            12 ?    bright   Conjunction
29P/Schwassmann-Wachmann      13 ?    varies   50 N to 55 S   morning
Lovejoy (2011 W3)            [13 ?    fade     20 N to 55 S   all night
LONEOS (2006 S3)              13.5    bright   Poor elongation
41P/Tuttle-Giacobini-Kresak   13.5    fade     Poor elongation
LINEAR (2010 S1)              14      steady   90 N to 10 N   evening
McNaught (2009 F4)            14 ?    steady   35 S to 55 S   early evening

The current update is only for 2011 W3 and 2012 A3.  The observable region is an approximate indication of the latitude at which the comet may be seen. Under good conditions comets may be visible outside this range. The period when visible is for the UK if the comet is visible from the UK, otherwise for 40 S or the Equator as appropriate. Beginners will often find comets fainter than about 7th magnitude difficult to locate - see below for information on positions and finder charts.

1. The comet discovered by Alan Watson in STEREO images may become visible for ground based observers towards the end of the month.  Rainer Kracht has computed a linked orbit with 2003 T12. 
2. The Comet's Tale Number 31, January 2012 is available for download
3. 2009 P1 (Garradd) is well condensed and an easy target with binoculars, even from suburban locations.
4. The small Kreutz comet 2011 W3 discovered by Terry Lovejoy peaked at around the brightness of Venus just before perihelion, but then faded. It was observed racing through the solar corona by SDO and re-emerged, minus its tail, in the SOHO-LASCO field. It became a spectacular Southern Hemisphere object, but has now faded and moonlight intereres. Terry Lovejoy managed to image it during daylight on December 17.0, when he estimated it at -1.2. A visual observation by Alexandre Amorim on December 17.34 put the comet at -2.9. Marco Goiato estimated it at 2.8 on December 22.3. The SOHO story. The absolute magnitude comet was some 5 magnitudes brighter post-perihelion than it was pre-perihelion. A likely explanation is that a part of the comet's surface was inactive prior to perihelion, and that as the nucleus rotated through the solar atmosphere the inert surface was eroded away, exposing fresh material. It is possible that as the comet recedes from the Sun, parts of the fresh surface will choke off, resulting in a relatively quick fading (it has faded as 15 log r). An international meeting about the comet will be held in Boulder, Colorado over March 21 and 22.
5. 29P/Schwassmann-Wachmann is having frequent outbursts. it was around 11th magnitude when it emerged from conjunction in November.
6. There will be a joint meeting of the Comet and Asteroid Sections of the BAA on Saturday, October 6 at Milton Keynes
7. Images of the month: Recovery image of 2010 X1 (Elenin) taken on 2011 October 22 showing the fading cloud. 45P/Honda-Mrkos-Pajdusakova taken by Rolando Ligustri on 2011 October 1 showing a long gas tail. 2009 P1 (Garradd) near the Coathanger taken by Rolando Ligustri on 2011 September 2

Details

• Details of the discovery, observations and analyses of comets which were discovered during 1995 , 1996 , 1997 , 1998 , 1999 , 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 , 2008 , 2009 [updated 2012 January 4], 2010 [updated 2012 January 4], 2011 [updated 2012 January 9] and 2012 [updated 2012 January 29].
• Details, observations and analyses of periodic comets numbered 1 - 100 [updated 2012 January 4], 101 - 199 [updated 2011 December 24], 200 - 299, [updated 2012 January 28] and cometary asteroids, potentially numberable comets and periodic SOHO comets [updated 2012 January 27].
• Previous images of the month Please use this Comet Image Naming Convention when submitting images.
• BAA Comet Section image archive This archive is updated whenever images are sent to <cometobs [at] britastro.org> or are received by Denis Buczynski <buczynski8166 [at] btinternet.com>
• The old Image archive has images to 2008 July 30 with earlier images available on request.
• Full IAUC details of SOHO Kreutz group and other comets announced during 2000 , 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 , 2008 [updated 2010 December 27], 2009 [updated 2010 December 27], 2010 [empty file], 2011 [empty file] and 2012 [empty file].
• A list of SOHO comets discovered during 2000, 2001 , 2002 , 2003 , 2004 , 2005 , 2006 , 2007 , 2008 , 2009 , 2010 [updated 2011 January 24], 2011 [updated 2012 January 1] and 2012 [updated 2012 January 28] and SOHO X/ comets.
• General information on Kreutz and sun approaching comets [updated 2009 May 12], on LASCO, STEREO and the Kreutz comets and a list of all SOHO comets [updated 2011 July 14].
• Daily news from 1999 / 2000 / 2001 / 2002 / 2003 / 2004 / 2005 / 2006 / 2007 / 2008 / 2009 / 2010 / 2011 / 2012.
• Comet news for SPA members for 2000 February / 2000 August / 2001 February / 2001 August / 2002 February / 2002 August / 2003 January / 2003 October / 2004 January / 2004 July / 2005 January / 2005 July / 2006 January / [updated 2006 January 23].
• Maik Meyer's comet mailing list
• Observations submitted in ICQ format for 2009 , 2010 and 2011, with November 2011 and October 2011 observations in extended TA format [Updated 2011 November]. Observations submitted or published in ICQ

Note that in general only details of currently visible comets are updated and that analyses of past years will be published in the BAA Journal.

• 29P/Schwassmann-Wachmann (12/01) UK or Equator or 40 South
• 45P/Honda-Mrkos-Pajdusakova (12/16) UK or Equator or 40 South
• 49P/Arend-Rigaux (01/18) UK or Equator or 40 South
• 78P/Gehrels (12/01) UK or Equator or 40 South
• 2009 P1 (Garradd) (12/01) UK or Equator or 40 South
• 2010 G2 (Hill) (01/02) UK or Equator or 40 South
• 2011 A3 (Gibbs) (08/18) is in conjunction UK or Equator or 40 South
• 2011 Q4 (SWAN) (01/17) UK or Equator
• 2011 W3 (Lovejoy) (12/22) Equator or 40 South
• 2012 A3 (P/SOHO) (01/29) UK or Equator or 40 South

• 2009 P1 (Garradd) remains near its brightest until March 2012
• 2011 L4 (PANSTARRS) may be a naked eye object in 2013 March

An explanation of the information in the ephemerides is given here. The following magnitude parameters, last updated 2011 November, are used in the ephemerides, but note that ephemerides are not updated every time the magnitude parameters are.

The following lists [updated 2012 January 17] give the ephemeris details, including the approximate current magnitude and local visibility for all the comets in the CBAT list for the UK, the equator and 40 south. CCD observers should try and observe any comets that have not recently been observed according to the CBAT but which are expected to be within range of their equipment. Negative observations are also useful.

For positions of newly discovered comets see the NEO confirmation page . You can also generate your own ephemerides and elements at the CBAT Minor Planet and Comet Ephemeris Service web page. Seiichi Yoshida has pages for currently visible comets, which include finder charts. Seiichi also has a comet rendezvous page, which lists conjunctions between comets, variable stars and nebulae and a comet recovery page, which lists periodic comets not yet recovered at the present return. The T3 project aims to discover comets amongst the population of asteroids influenced by Jupiter. Following a hack at the MPC, MPECs etc are now available at this site

Finder charts

A plot of recent search areas by professional teams looking for NEOS.

Orbits etc

Downloads etc

Download the January 2012 newsletter.

Download Richard Fleet's GraphDark software for graphically displaying comet (and other object) visibility. Latest version is 2.05, 2007 May.

Download William Schwittek's CometWin software for generating comet ephemerides and visibility diagrams. [Updated 2002 March 5]

Download Solex, N-body solar system dynamics software.

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Many thanks to those that regularly access this page for your interest. If you have any comments, suggestions for improvement or find any problems, please mail the comet section director, Jon Shanklin, but please make sure that it is possible to reply to your address. If you need to phone me, my home number is +44 (0)1223 571250 or my work number is +44 (0)1223 221400. The work fax is +44 (0)1223 221279 I can also be contacted at j.shanklin @ bas.ac.uk and snail mail will reach me at British Antarctic Survey, Madingley Road, CAMBRIDGE CB3 0ET, England. For information about my day job I have a web page at BAS.