British Astronomical Association

Comet Section

Director: Nick James

Visual observations page


(Co-ordinator Jonathan Shanklin)

Latest Discoveries 

Jul 04  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 04  Robert Pickard reports a Kreutz group comet in archival C2 images
Jul 08  Recovery of 2012 S2 (P/La Sagra) as 2021 L5 reported
Jul 09  Cometary activity (tail) reported in (248370) 2005 QN173
Jul 13  Discovery of 2021 N1 (P/ZTF) reported
Jul 13  Rafal Biros reports a Kreutz group comet in archival C2 images
Jul 13  Salil Mulye reports a Kreutz group comet in real time C3 images
Jul 13  Worachate Boonplod reports a non-group comet in real time C3 images
Jul 13  Worachate Boonplod reports a Meyer group comet in real time C2 images
Jul 14  Sergey Shurpakov reports a Kreutz group comet in real time C3 images
Jul 15  Discovery of 2021 N2 (P/Fuls) reported
Jul 16  Masanori Uchina reports a Kreutz group comet in real time C3 images
Jul 19  Robert Pickard reports a Kreutz group comet in archival C2 images
Jul 19  Rafal Biros reports a Kreutz group comet in archival C2 images
Jul 19  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 20  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 22  Discovery of 2021 N3 (PanSTARRS) reported
Jul 23  Robert Pickard reports a Kreutz group comet in archival C2 images
Jul 25  Discovery of 2021 O1 (Nishimura) reported
Jul 25  Peter Berrett reports a non-group comet in archival C2 images
Jul 25  Rafal Biros reports a Kreutz group comet in archival C2 images
Jul 27  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 28  Robert Pickard reports a Kreutz group comet in archival C2 images
Jul 28  Peter Berrett reports a non-group comet in delayed C2 images
Jul 30  Recovery of 2005 W3 (P/Kowalski) as 2021 O2 reported
Aug 01  Discovery of 2021 O3 (PanSTARRS) reported
Aug 03  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 2021 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
2021 O1 (Nishimura)            9.5    steady    Poor elongation                    Not yet observed
2020 T2 (Palomar)             11      fade      45 N to 75 S   evening             2021 July
15P/Finlay                    11      fade      50 N to 30 S   early morning       2021 July
2019 L3 (ATLAS)               11.5    bright    55 N to 10 N   morning             2021 July
4P/Faye                       12      bright    55 N to 50 S   morning             2021 July
2017 K2 (PanSTARRS)           12.5    bright    55 N to 20 S   best evening        2021 July
7P/Pons-Winnecke              12.5    fade      10 N to 90 S   best morning        2021 July
29P/Schwassmann-Wachmann      13 ?    varies    50 N to 20 S   early morning       2021 January
10P/Tempel                    13.5    fade      45 N to 50 S   morning             2021 July
2020 J1 (SONEAR)              13.5    fade      30 N to 65 S   evening             2021 July
2019 T4 (ATLAS)               14      steady    Poor elongation                    2021 July
67P/Churyumov-Gerasimenko     14.5    bright    55 N to 55 S   morning             2021 July
Details are usually updated at the beginning of each month, but may be updated more frequently for brighter comets.  The last update was on August 3.  The magnitude is a rough value for the mean magnitude reported; some observers will see the comet brighter than this, whilst others will see it fainter.  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 O3 (PanSTARRS) may be visible to UK observers next May as a 6th magnitude object, initially in the evening sky but quickly becoming visible all night.  It will fade rapidly.  It does however have a relatively faint absolute magnitude, so may not survive perihelion.
  2. Although some sources are hyping the prospects for 2021 A1 (Leonard), which might or might not reach 4th magnitude at the end of the year, they do not mention that the comet will be visible in the morning sky.  You will need to be up at 6am to see it.  Current electronic observations suggest that it has a faint absolute magnitude and is only brightening slowly.  It might reach 7th magnitude.
  3. 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.
  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 2021 February Journal included a paper on "The brighter comets of 2017".  Further papers in this series (2018 - 2019) and a paper drawing conclusions from the series are in press.

Details

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 August 3) 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 August 3], 2023 [Updated 2021 July 3] and 2024 [Created 2021 February 3] are published in the BAA Journal in December each year. This list [Updated 2021 August 2] 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] ast.cam.ac.uk> 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 Chris Wyatt 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 @ bas.ac.uk. 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.

Published by jds@ast.cam.ac.uk