British Astronomical Association

Comet Section

Director: Nick James

Visual observations page

(Co-ordinator Jonathan Shanklin)

Latest Discoveries

Dec 17  Discovery of 2020 X3 (SOHO) reported
Dec 18  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Dec 21  Trygve Prestgard reports a Kreutz group comet in real time C2 images
Dec 22  Trygve Prestgard reports a Kreutz group comet in real time C2 images
Dec 23  Masanori Uchina reports two Kreutz group comets in real time C2 images
Dec 29  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Dec 31  Worachate Boonplod reports a Kreutz group comet in real time C2 images
Jan 02  Michal Biesiada reports a Kreutz group comet in real time C3 images
Jan 05  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jan 07  Recovery of 2007 B1 (P/Christensen) as 2020 W3 reported
Jan 07  Recovery of 2010 B2 (P/WISE) as 2020 Y1 reported
Jan 07  Recovery of 2016 J3 (P/STEREO) not formally reported
Jan 08  Discovery of 2020 Y2 (ATLAS) reported
Jan 10  Discovery of 2021 A1 (Leonard) reported
Jan 10  Discovery of 2021 A2 (NEOWISE) reported
Jan 10  Discoery of 2020 X4 (Leonard) reported
Jan 11  Recovery of 2014 E1 (P/Larson) reported (as 2020 W4)
Jan 11  Worachate Boonplod reports a Meyer group comet in real time C2 images
Jan 15  Discovery of 2020 W5 (Lemmon) reported
Jan 15  Discovery of 2020 Y3 (ATLAS) reported
Jan 15  Discovery of 2021 A4 (NEOWISE) reported
Jan 15  Discovery of 2021 A5 (P/PanSTARRS) reported
Jan 15  Discovery of 2021 A6 (PanSTARSS) reported
Jan 15  Discovery of 2021 A7 (NEOWISE) reported
Jan 16  Update

If there have been no recent updates try The German comet group page or Seiichi Yoshida's page for information or the Liga Iberoamericana de Astronomia for observations.

Elsewhere on these pages: Highlights / Newly discovered comets / Periodic comets / Contributing observations / Comet Ephemerides / Upcoming Comets / Observing Comets / Links / Meetings / Publications / Comments and Contacts / Old 2020 News / Comet discovery procedure / Weather information / The Comet's Tale / BAA Comet Section image archive / Project Alcock / More information / Legacy page / Main BAA Comet Section page

Current comet magnitudes and observable region

Comet	                  Magnitude   Trend     Observable     When visible        Last visual observation
2020 S3 (Erasmus)              9      fade      Conjunction                        2020 December
141P/Machholz                 10.5    fade      55 N to 35 S   early evening       2021 January
2020 R4 (ATLAS)               10.5    bright    Poor elongation                    2021 January
2020 M3 (ATLAS)               11      fade      90 N to 20 S   all night           2021 January
2019 N1 (ATLAS)               11 ?    steady    20 N to 50 S   morning             2020 August
88P/Howell                    11      fade      35 N to 20 S   early evening       2021 January
156P/Russell-LINEAR           11.5    fade      90 N to 30 S   best evening        2021 January
2021 A2 (NEOWISE)             12      bright    10 N to 55 S   all night           2021 January
11P/Tempel-Swift-LINEAR       12      fade      65 N to 45 S   evening             2020 December
398P/Boatttini                12      steady    65 N to 50 S   best evening        2021 January
29P/Schwassmann-Wachmann      13 ?    varies    85 N to 35 S   best evening        2021 January
2017 T2 (PanSTARRS)           13      fade      Poor elongation                    2020 September
162P/Siding Spring            13      fade      70 N to 25 S   evening             2020 December
58P/Jackson-Neujmin           14 ?    fade      65 N to 50 S   best midnight       2020 August
2019 L3 (ATLAS)               14      bright    90 N to  0 N   best evening        2020 December
2020 N1 (PanSTARRS)           14      bright    90 N to 15 S   evening             2020 December
2017 K2 (PanSTARRS)           15      bright    90 N to 35 N   morning             2020 September

Details are usually updated at the beginning of each month, but may be updated more frequently for brighter comets.  The last update was on January 5.  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.  The last visual observation is as received by the Section, details are often updated on the basis of observations published elsewhere.   Beginners will often find comets fainter than about 7th magnitude difficult to locate - see below for information on positions and finder charts.

Highlights and News  

  1. New comet 2021 A2 is rapidly moving north and may be visible from the UK by the end of January.  It may brighten by about another magnitude.
  2. I would like to thank all those who have sent me congratulations on the naming of a small piece of Antarctica as Shanklin Glacier.  Exploration of icy parts of the world clearly runs in the blood as my great-grandfather kept diaries which record the passage of a comet below the Plough, the discovery of a comet by his brother, Bernard Thomas, from Tasmania and the expeditions to Antarctica by Scott and Shackleton.  See also this BBC report.
  3. 2020 S3 will now remain too close to the sun for any further observation and is fading.
  4. The Section welcomes observations from all comet enthusiasts, whether members of the BAA or not.  An advantage of joining the BAA is that you can read papers on comets published in the BAA Journal.  The 2020 June Journal included a paper on "The brighter comets of 2016".  Further papers in this series are in press or under review (2017 - 2019).


Comet ephemerides (positions) etc

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.  The elements and ephemerides from the JPL Small-Body Database Browser give estimates of the errors, which are often far larger than might be thought from the accuracy of the elements given by the CBAT.  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. 

Planning aids and information for forthcoming comets, valid out to about 2025.

  • Comets reaching within three degrees of 180° opposition [updated 2013 December 31]
  • Comets reaching within three degrees of zero phase angle [updated 2013 December 31]

The MPC also has a list of the last observation for all comets.  Electronic 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.  In addition, the MPC has orbital elements for unusual asteroids, many of which have cometary orbits. 

Finder charts

The BAA Computing Section has online charts for the comets listed here. There are daily finder charts for bright comets at Heavens Above. Reinder Bouma and Edwin van Dijk's astrosite Groningen has an excellent set of finder charts for brighter comets, which also show suitable comparison stars.

Orbits etc

The elements and ephemerides from the JPL Small-Body Database Browser give estimates of the errors, which are often far larger than might be thought from the accuracy of the elements given by the CBAT.   Full details of the latest orbits are available from Kazuo Kinoshita's Comet Orbit Home Page.  I compile orbital elements in Megastar format for: numbered periodic comets , recent comets (updated 2021 January 5) and comets prior to 2006.  Most of the more recent elements include the latest magnitude parameters.  The elements are from a mix of CBAT catalogues, MPC, MPEC, JPL and individual orbit computers.

Downloads etc

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.

Upcoming comets

Predictions for the comets expected to return in 2021 [updated 2021 January 15], 2022 [updated 2021 January 15] and 2023 [Created 2021 January 16] are published in the BAA Journal in December each year. This list [Updated 2021 January 16] gives the period of visibility and maximum brightness for comets that are predicted to be visible within the next few years. A few are listed further into the future. Seiichi Yoshida also has a list of comets likely to be visible in the next five years.

Contributing observations

Observations may  be used in the reports on comets which appear on these pages, in The Comet's Tale and in the BAA Journal. Guidance on observing is given in the BAA Comet Observing Guide

Thanks to the many observers who do send in their observations in ICQ format.  Imagers are encouraged to reduce their observations to equivalent visual magnitude (see Project Alcock ) and submit them in this format.  Do check the observation files to see if what you sent matches what is there, as I still have to edit some of the submitted records, particularly the position of "m" when tail length is given in minutes, the focal ratio and the designation of periodic comets 1-99.  If your observations are missing it may be because you have not used the correct format, which includes ICQ as a key.  If you use the Comet Observation Database to enter your observations they will be formatted correctly, but please send them to me for inclusion in TA.

Visual and visual equivalent magnitude observations should be sent to me at <jds [at]> in simple text format.  Visual observers can use the BAA visual report form to log observations.  To avoid the use of multiple formats the ICQ format , which uses special keys to code observation particulars, is now standardised as the one to use for submission and archiving of observations.  The ICQ have not updated their observation keys since 2010, so these additional keys are suggested for use when submitting observations to the BAA (updated 2020 October 3).   Crni Vhr Observatory has launched the Comet Observation Database which allows entry of observations in ICQ format, and plots of light curves.  Visual observations entered using this system should be emailed to me at the end of the month.  Observations are usually analysed and sent to TA as soon as possible after the end of the month with a TA deadline of the 2nd; any late observations will be used in subsequent analyses.  Observations will continue to be published by Guy Hurst in The Astronomer magazine in TA format. There is also a visual drawing form.   The German comet group also has a computer program that will correctly format observations for the ICQ [2009 December]. 

Images should be sent to Denis Buczynski.

Regular contributors include James Abbott, Jose Aguiar, Alexander Amorim, Nicolas Biver, Denis Buczynski, Paul Camilleri, Peter Carson, Matyas Csukas, Roger Dymock, John Fletcher, Marco Goiato, Juan Gonzalez, Bjorn Granslo, Werner Hasubick, Kevin Hills, Nick James, Heinz Kerner, Carlos Labordena, Rolando Ligustri, Michael Mattiazzo, Maik Mayer, Antonio Milani, Martin Mobberley, Jose Navarro Pina, Gabriel Oksa, Mieczyslaw  Paradowski, Nirmal Paul, Stuart Rae, Walter Robledo, Tony Scarmato, Willian Souza, David Strange Johan Warrell and Seiichi Yoshida, several of whom contribute observations from their colleagues.  Thanks are due to all of them.

Warning I receive a large number of emails containing viruses or other junk. Please try and make clear that your message is legitimate, otherwise it may be deleted without being read. It is advisable to use your own name, rather than an alias, in the 'from' field and use an obvious, recent subject.

Comments and contact

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 email the visual co-ordinator, Jon Shanklin, at j.shanklin @ If you need to phone me, my home number is +44 (0)1223 571250 or my BAS number is +44 (0)1223 221482. Snail mail will reach me at the British Antarctic Survey, Madingley Road, CAMBRIDGE CB3 0ET, England. For information about my work with BAS see my web page at BAS.

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