The aim of this service is to provide charts (using Guide 9.0) and suitable comparison stars
for relatively bright comets,
i.e. brighter than magnitude 10-11, to aid observers in making brightness estimates.
To avoid confusion with Flamsteed numbers we have underlined the magnitudes of all comparison stars.
Stars with B-V<1.0 were selected where possible; those with B-V>1.0 are given in italics, and should only
be used when no suitable alternatives are available.
The source of the comparison stars on these standard charts is primarily the Tycho-2 catalog, of which only VT-magnitudes
are used. When reporting data to the ICQ (International Comet Quarterly) the source code thus should be given as TK,
unless indicated otherwise.
We plan to issue new charts on a regular basis, if possible not later than 2 days before the date of first observation.
Occasionally we also issue special charts for fainter comets that are of particular interest.
Below magnitude 10-11 comparison stars usually are taken from a different source (such as APASS with ICQ code AQ,
ASAS-3 with ICQ code AU and TASS4 with ICQ code TA), because Tycho-2 is becoming very unreliable here.
It should be noted also that the ICQ advises against the use of Tycho-2 for comets fainter than magnitude 10.5.
So be sure to always check the proper code(s) given on the top right corner of the chart.
If you wish to be informed about the issue of new charts you can
subscribe to our charts-info service.
Send us a message with in the body 'subscribe charts-info' and your email address, by clicking here.
Your email address will only be used to send you our charts-info, and it will not be made available to other persons.
Please, make sure that your email settings/SPAM filters are allowing our messages to get through.
If they bounce repeatedly, for whatever reason, your address will be removed from our mailing list.
Currently we have charts available for:
C/2012 K1 (PANSTARRS)
C/2012 K1 (PANSTARRS)
Chart 11 C/2012 K1 (PANSTARRS) period 3 September - 19 September 2014
Chart 12 C/2012 K1 (PANSTARRS) period 19 September - 30 September 2014
Chart 13 C/2012 K1 (PANSTARRS) period 30 September - 9 October 2014
Chart 14 C/2012 K1 (PANSTARRS) period 11 October - 19 October 2014
Chart 15 C/2012 K1 (PANSTARRS) period 19 October - 27 October 2014