British Astronomical Association

Comet Section

Director: Nick James

Visual observations page


(Co-ordinator Jonathan Shanklin)

Latest Discoveries

Apr 04  Szymon Liwo reports a Kreutz group comet in real time C2 images
Apr 04  Discovery of 2016 G1 (P/PanSTARRS) reported
Apr 07  Discovery of 2015 HG16 (P/PanSTARRS) reported
Apr 15  Bo Zhou reports a Kreutz group comet in real time C2 images
Apr 16  Bo Zhou reports a Kreutz group comet in real time C2 images
Apr 19  Khadija El Kanbi reports a Kreutz group comet in real time C2 images
Apr 19  2015 WZ (PanSTARRS) reclassified as a comet
Apr 20  Zhijian Xu reports a Kreutz group comet in real time C2 images
Apr 22  Worachate Boonplod reports a Kreutz group comet in real time C3 images
Apr 24  Bo Zhou reports a Kreutz group comet in real time C3 images
Apr 26  Worachate Boonplod reports a Kreutz group comet in real time C2 images
Apr 30  Worachate Boonplod reports a Kreutz group comet in real time C3 images
May 01  Worachate Boonplod reports a Kreutz group comet in real time C2 images
May 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 2016 News / Comet discovery procedure / Weather information / The Comet's Tale / BAA Comet Section image archive / Project Alcock / More information / Legacy page

Current comet magnitudes and observable region (May 3)

Comet	                  Magnitude   Trend    Observable     When visible        Last visual observation
PanSTARRS (2013 X1)            7.5    steady   40 N to 85 S   morning             2016 May
252P/LINEAR                    8      fade     60 N to 70 S   all night           2016 May
PanSTARRS (2014 S2)           10.5    fade     60 N to 25 S   all night           2016 May
81P/Wild                      11      bright   55 N to 40 S   evening             2016 April
PanSTARRS (2015 WZ)           11      bright   55 N to 25 S   all night           2016 May
Catalina (2013 US10)          11.5    fade     60 N to 20 N   evening             2016 April
PanSTARRS (2014 W2)           12.5    steady   60 N to 10 N   all night           2016 April
116P/Wild                     12.5    steady   35 N to 85 S   best morning        2016 April
104P/Kowal                    12.5    fade     Poor elongation                    Not yet observed
9P/Tempel                     13      bright   60 N to 40 S   best evening        2016 April
Spacewatch (2011 KP36)        13      steady    0 N to 40 S   morning             2015 September
29P/Schwassmann-Wachmann      13 ?    varies   35 N to 90 S   morning             2015 October
Lovejoy (2014 Q2)             13      fade     60 N to 35 S   best morning        2015 October
77P/Longmore                  13.5    steady   35 N to 65 S   best evening        2016 April
333P/LINEAR                   13.5    fade     Poor elongation                    2016 March
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 update 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. 252P/LINEAR made a close pass (0.0356 au) on March 21 and reached 4th magnitude, but is now fading.  It is a large, diffuse, object and may be difficult to see from sites affected by light pollution.  It is best seen in the morning sky.  It brightened rapidly and, as is often the case with such objects, there were reports that the comet was in outburst, however the degree of condensation remained low.  A linear light curve fits the observations best, with the comet at peak output 35 days after perihelion.  The rate of brightening was unusually rapid.  Marco Goiato reported that the coma was 150' across around the time of closest approach and visible to the naked eye.
  2. 2013 X1 was recovered by Marco Goiato on April 17.35 in 20x100B.  It was fainter than was expected at 7.5, but is moderately condensed.  The observations are best fitted by a linear light curve, with the comet intrinsically brightest about a month before perihelion.  If this is correct it will brighten a little as it approaches the Earth, then fade rapidly.
  3. 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 April Journal included a paper on "The brighter comets of 2007".  Further papers in this series are in press or in draft.
  4. 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 March 16) to see if what you sent matches what is there, as I still have to edit some of the submitted records, particularly the positioning of the DC, which should go in column 56, and the position of "m" when tail length is given in minutes.  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.

Details

252p.jpg (261926 bytes)2013x1.jpg (342826 bytes)


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.

Planning aids and information for forthcoming comets

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 the January 2015 newsletter, which has a report of an RAS meeting, an article on Rosetta, plus the usual reviews and forecasts.  

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 2015 , 2016 [updated 2016 March 17] , 2017 [updated 2016 March 17] and 2018 [updated 2016 January 2] are published in the BAA Journal in December each year. This list [Updated 2016 March 17] gives the period of visibility and maximum brightness for comets that are predicted to be visible within the next couple of 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.

Visual and visual equivalent magnitude observations should be sent to me at <jds [at] ast.com.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 is now standardised as the one to use for submission and archiving of observations, however the ICQ have not updated their observation keys since 2010.  These additional keys are suggested for use when submitting observations to the BAA (updated 2015 February 1).  Observations will continue to be published by Guy Hurst in The Astronomer magazine in TA format. There is also a visual drawing form.   I have written a data entry program that creates a file with data in the ICQ format which you can send to me by email. It now runs under Windows and is available as a self extracting zip file. [New version, 2004 February 2]. I have also written a program to convert from ICQ to TA format. 

Images should be sent to Denis Buczynski.

The German comet group also has a computer program that will correctly format observations for the ICQ [2009 December]. Crni Vhr Observatory has launched the Comet Observation Database which allows entry of observations in ICQ format, and plots of light curves. The ICQ format uses special keys to code observation particulars. 

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, Kevin Hills, Nick James, Werner Hasubick, Heinz Kerner, Carlos Labordena, Rolando Ligustri, Michael Mattiazzo, Maik Mayer, Antonio Milani, Martin Mobberley, Gabriel Oksa, Mieczyslaw  Paradowski, Stuart Rae, Walter Robledo, Tony Scarmato, Willian Souza, David Strange and Seiichi Yoshida, several of whom contribute observations from their colleagues.

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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