British Astronomical Association

Comet Section

Director: Nick James

Visual observations page

(Co-ordinator Jonathan Shanklin)

Latest Discoveries

Jul 18  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 22  Rainer Kracht reports a Meyer group comet in real time C2 images
Jul 23  Masanori Uchina reports a Meyer group comet in real time C2 images
Jul 24  Zhijian Xu reports a Kreutz group comet in real time C3 images
Jul 30  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Jul 31  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Aug 01  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Aug 11  Rainer Kracht reports a Marsden group comet in real time C2 images
Aug 11  Worachate Boonplod reports a Marsden group comet in real time C2 images
Aug 12  Masanori Uchina reports a Meyer group comet in real time C2 images
Aug 13  Recovery of 2010 A1 (P/Hill) as 2018 P1 by Eric Schwab reported
Aug 13  Recovery of 2001 T3 (P/NEAT) as 2018 P2 by Eric Schwab reported
Aug 13  Cometary activity found in 2018 KJ3
Aug 13  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Aug 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 2018 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 (August 16) and observable region (August 1)

Comet	                  Magnitude   Trend    Observable     When visible        Last visual observation
21P/Giacobini-Zinner           8      bright   55 N to 10 S   all night           2018 August
PanSTARRS (2017 S3)            8      steady?  55 N to  5 S   morning             2018 August
PanSTARRS (2016 M1)            9      fade     20 N to 90 S   best evening        2018 August
ATLAS (2017 T3)                9      fade     30 S to 90 S   early morning       2018 July
NEOWISE (2018 N1)              9.5    fade     45 N to 90 S   best evening        2018 August
38P/Stephan-Oterma            11      bright   45 N to 50 S   morning             2018 August
37P/Forbes                    12      fade     55 N to 60 S   best morning        2018 August
PanSTARRS (2016 R2)           12      fade     Poor elongation                    2018 August
Lemmon (2018 EF9)             12.5    fade     Poor elongation                    2018 May
PanSTARRS (2016 N6)           12.5    steady   Conjunction                        2018 June
46P/Wirtanen                  13 ?    bright   40 N to 70 S   morning             Not yet observed
364P/PanSTARRS                13      fade     15 N to 75 S   morning             2018 August
64P/Swift-Gehrels             13      bright   60 N to 45 S   best morning        2018 August
66P/du Toit                   13      fade     30 N to 65 S   morning             2018 July
240P/NEAT                     13 ?    steady   Poor elongation                    Not yet observed
29P/Schwassmann-Wachmann      13 ?    varies   55 N to 65 S   best morning        2018 August
ATLAS (2018 L2)               13.5    bright   20 N to 70S    evening             Not yet observed
ATLAS (2017 M4)               13.5    steady   55 N to 20 S   best evening        2018 July
48P/Johnson                   13.5    steady   35 N to 80 S   best morning        2018 August
PanSTARRS (2015 O1)           13.5    fade     Poor elongation                    2018 July
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.   Details are normally fully updated at the beginning of each month, but may be updated more frequently for comets brighter than 10th magnitude; the date of the most recent partial update, which may apply to only one object, is given.  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. 21P/Giacobini-Zinner is brightening quite rapidly as its distance from both the Sun and Earth are decreasing.  In addition it intrinsically brightens quite rapidly.  It is now visible in large binoculars from central Cambridge.
  2. Gas emission from 2017 S3 seems to be quite eratic, leading to irregular changes in the brightness of the comet.  Overall it should continue to brighten, but the current magnitude could differ from that given above by a couple of magnitudes.  It is in conjunction.
  3. 2017 T3 is reported at around 10th magnitude in the twilight.  It will not become visible from the UK.
  4. There is to be a Pro-am observing campaign on 46P/Wirtanen in 2018.  There is a brief observing window for UK observers in September which will be useful for determing the magnitude parameters at this return, but it is best seen from the southern hemisphere during this period.   It quickly moves into the evening sky in mid November, and could be a naked eye object in December.  It makes a close approach to Earth on 2018 December 16, passing 0.078 au from us.  It could remain within visual range until March 2019.
  5. The final update on comet predictions for 2018 was posted in 2018 February. The comet predictions for 2019 were updated in 2018 February. The preliminary 2020 predictions were posted in 2017 October. 
  6. 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 2018 June Journal included a paper on "The brighter comets of 2012".  Further papers in this series are in press (2013 - 2014) or under review (2015).
  7. Thanks to the many observers who have sent 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 (updated August 1) 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 and the focal ratio.  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.


2016 M1

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. 

Longer period ephemerides are given here for planning purposes for comets that may reach naked eye brightness. All are for the UK.  The ephemerides give B1950 and J2000 positions.  Modern star charts use J2000, but older atlases will use B1950.  The predicted magnitudes are extremely uncertain. 

  • None at present

Planning aids and information for forthcoming comets

  • 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.

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: periodic comets , current comets , comets prior to 2005.  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 2017 , 2018 [updated 2018 February 1] , 2019 [updated 2018 February 1] and 2020 [created 2017 October 25] are published in the BAA Journal in December each year. This list [Updated 2018 August 16] gives the period of visibility and maximum brightness for comets that are predicted to be visible within the next five 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

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 2017 January 4).   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; 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, 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, Stuart Rae, Walter Robledo, Tony Scarmato, Willian Souza, David Strange Johan Warrell and Seiichi Yoshida, several of whom contribute observations from their colleagues.

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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