British Astronomical Association

Comet Section

Director: Nick James

Visual observations page


(Co-ordinator Jonathan Shanklin)

Latest Discoveries and news

Aug 22  Jiangao Ruan reports a Kreutz group comet in real time C2 images
Aug 24  Zhijian Xu reports a Kreutz group comet in real time C3 images
Aug 26  Recovery of 2014 W1 (P/PanSTARRS) as 2023 O2 reported
Aug 28  Recovery of 13P/Olbers reported
Aug 28  Zhijian Xu reports a Meyer group comet in real time C2 images
Aug 29  Jiangao Ruan reports a non-group comet in real time C2 images
Sep 04  Zesheng Yang reports a Kreutz group comet in real time C3 images
Sep 06  Robert Pickard reports a Kreutz group comet in real time C3 images
Sep 08  Cometary activity in 2023 KF3 reported
Sep 12  Jiangao Ruan reports a non-group comet in real time C2 images
Sep 12  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Sep 14  Discovery of 2023 R1 (PanSTARRS) reported
Sep 17  Robert Pickard reports a Kreutz group comet in real time C3 images
Sep 18  Robert Pickard reports a Kreutz group comet in archival C2 images
Sep 21  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 2023 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 for 2023 September

Comet	                  Magnitude   Trend     Observable     When visible        Last visual observation
2023 P1 (Nishimura)            3      fade      Poor elongation                    2023 September
103P/Hartley                  10      steady    65 N to 30 S   all night           2023 September
2020 V2 (ZTF)                 10      steady    60 N to 85 S   morning             2023 September
2023 H2 (Lemmon)              11      bright    75 N to 45 N   evening + morning   2023 September
2023 E1 (ATLAS)               11      fade      65 N to 50 S   best evening        2023 September
2021 T4 (Lemmon)              11      fade      30 N to 80 S   evening             2023 August
2017 K2 (PanSTARRS)           11.5    fade      35 N to 70 S   morning             2023 June
2P/Encke                      12      bright    65 N to 25 S   morning             2023 September
12P/Pons-Brooks               12      outburst  65 N to  5 S   best evening        2023 September
2021 S3 (PANSTARRS)           12.5    bright    30 S to 80 S   early morning       2023 June
185P/Petriew                  12.5    steady    Poor elonation                     2023 July
2022 A2 (PanSTARRS)           13      fade      65 N to 40 S   best morning        2023 September
2020 K1 (PanSTARRS)           13      fade      30 S to 85 S   early evening       2023 July
29P/Schwassmann-Wachmann      13 ?    varies    Poor elongation                    2023 January
2019 L3 (ATLAS)               13      fade      75 S to 85 S   best morning        2023 July
237P/LINEAR                   13.5    fade      55 N to 60 S   best evening        2023 August
2019 U5 (PanSTARRS)           13.5    fade      Poor elonation                     2023 July
2022 JK5 (PanSTARRS)          14      fade      30 N to 85 S   best morning        Not yet observed
144P/Kushida                 <14      bright    65 N to 40 S   best morning        Not yet observed
226P/Pigott-LINEAR-Kowalski  <14      bright     0 N to 85 S   best morning        Not yet observed
Details are usually fully updated at the beginning of each month, but some minor updates may be made more frequently, particularly for brighter comets.  The last (partial) update was on September 19.  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 30 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. 2023 P1 (Nishimura) has passed perihelion, but will remain at a small solar elongation. Despite the small elongation JJ Gonzalez was able to observe it on September 18. Nick James also imaged it from La Palma the same day. It is unlikely to be observed again until it has faded below 10th magnitude.
  2. JJ Gonzalez reports 2023 H2 as being significantly brighter than expected. It should brighten further and become better placed for observation.
  3. 2021 S3 could reach 7th magnitude at perihelion in 2024 February.
  4. Comet 2023 A3 is causing much speculation.  The comet is still over 5 au from the Sun and the error bars on the extrapolated magnitude at perihelion remain huge, though are decreasing.  They are however still around 6 magnitudes!  Even assuming a rate of brightening the comet could be anything from a naked eye object to one only visible in binoculars.  I suggest waiting for more observations and for the comet to get closer to the Sun first.
  5. The section is collaborating with the Italian CARA group in a campaign to observe 103P/Hartley. The comet has a linear light curve and is intrinsically brightest some 24 days after perihelion, which is in mid October. The comet passes 0.4 au from the Earth at the end of September, when it could be 9th magnitude. It could reach 8th magnitude in early November, but is then a morning object. VEM broadband and visual observations are desirable in addition to the more specialist observations used by the campaign.
  6. There was a BAA Comet Section meeting in London on 2023 July 8.  Talks were recorded and should be available for viewing in the near future.
  7. 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 2023 June Journal included a paper on "BAA comet observations: magnitude parameters".  Further papers in "The brighter comets of" series are in press (2020), or have been submitted (2021). 2022 is in preparation.  Best wishes go to our colleagues in the Ukraine.

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 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 2023 July 28 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 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 2022 [updated 2022 January 7], 2023 [Updated to 2023 January 1], 2024 [Updated 2023 June 2] and 2025 [Updated 2023 July 23] are published in the BAA Journal in December each year. This list [Updated 2023 September 19] 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 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. 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.
 

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, 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 my web 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