III. Photometry for the years 1993-2001
Astronomy Division, PO Box 3000, 90014 University of Oulu, Finland
2 Observatory, PO Box 14, 00014 University of Helsinki, Finland
3 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany
4 Astronomical Institute of the Academy of Sciences of Uzbekistan, Astronomicheskaya 33, Tashkent 700052, Uzbekistan
5 Tuorla Observatory, University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
6 Dipartemento di Fisica, Universita degli Studi di Padova, Via 8 Febbraio, 2, 35122 Padova, Italy
Corresponding author: H. Korhonen, firstname.lastname@example.org
Accepted: 30 May 2001
We present 8 years of previously unpublished photometric observations of FK Com together with the determination of the stability of the primary comparison star HD 117567. The observations have been carried out between 1993 and 2001 at four different observatories and they consist of 5157 data points in total: U(903), B(994), V(1643), R(166), Ic(573), b(461) and y(417). We also analyse this new data together with the previously published photometric observations. The V magnitude shows variations with dominant periods of about 3, 6, 12, 14 and 31 years. The short-term light curve variations appear to be caused by rearrangement of approximately constant amount of cool spots. From the values for different colours obtained during the brightest season observed, corresponding to the supposedly unspotted surface, the spectral type of FK Com is determined to be G7 III.
Key words: stars: individual: FK Com / stars: individual: HD 117567 / stars: starspots / stars: variables: general
Based on the observations obtained at Phoenix 10, Arizona, USA; Wolfgang and Amadeus, Arizona, USA; Mount Maidanak Observatory, Uzbekistan; La Palma KVA 0.6 m Cassegrain telescope, La Palma, Spain.
© ESO, 2001