BAA Comet section (original) (raw)

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

The MPC also has a list of the last observationfor 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.

The elements and ephemerides from the JPL Small-Body Database Browsergive 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 were available from Kazuo Kinoshita's Comet Orbit Home Page (Kazuo died in 2021 July and his web page hadn't been updated since 2020 February). I compile orbital elements in Megastar format for: numbered periodic comets , recent comets (updated 2025 June 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. Older elements are for the epoch of perihelion, but most recent elements from the MPEC are for epoch of date.

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 softwarefor 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 2025[Final edition 2025 January 1] , 2026[Updated 2024 June 24] and 2027[Created 2025 January 1] are published in the BAA Journal in December each year. This list [Updated 2025 May 28] gives the period of visibility and maximum brightness for comets that are predicted to be brighter than 12th magnitude within the next few years. A few are listed further into the future. Seiichi Yoshida also has a listof 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 (seeProject 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 theComet Observation Database to enter your observations they will be formatted correctly. I extract all the observations from observers who are affiliated to the BAA on a monthly basis for publication in TA, but other observers will need to send them to me. Observers providing VEMs are reminded that they should report a coma diameter to go with the magnitude.

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 maintains the Comet Observation Database which allows entry of observations in ICQ format, and plots of light curves. Visual observations entered using this system are extracted for observers affiliated to the BAA. Observations are usually analysed and comet notes sent to TA as soon as possible after the end of the month with a TA deadline of the 6th; any late observations will be used in subsequent analyses. Raw observations are no longer published in The Astronomermagazine as they are available in the Comet Observation Database. Subjective data will continue to be published in TA. 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, Giuseppe Pappa, 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 myweb page at BAS. There is a small piece of Antarctica named as Shanklin Glacier. See also this BBC report. 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. A write up of my George Alcock lecture, which tells a little of the Antarctic story was published in the 2021 October BAA Journal.

Published by jds@ast.cam.ac.uk