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Long-Term Spot Photometry and Differential Rotation of the Spotted Flare Stars Ev Lac and by Dra

Published online by Cambridge University Press:  19 July 2016

K.P. Panov
K.P. Panov*
Affiliation:
Department of Astronomy and National Astronomical Observatory, Bulgarian Academy of Sciences, 72 Trakya Blvd, 1784 Sofia, Bulgaria

Extract

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Ev Lac = Gliese 873 (dM4.5e) is a well-known flare star with hydrogen Balmer lines as well as with Ca II lines in emission. Rotational modulation by starspots has been discovered by Pettersen (1980) who determined the photometric (rotational) period P = 4.378 d. Spot photometry of EV Lac was obtained with the 60 cm telescope of the Bulgarian National Astronomical Observatory in the years 1983–87 and 1989–91. For these years (except for 1989 and 1990) light curves are available in the V and B bands. From the BNAO-data and the data published by Pettersen (1980) a new ephemeris has been derived which shows a slight revision of the period.

Type
4. Late-Type and Other Stars
Information
Symposium - International Astronomical Union , Volume 157: The Cosmic Dynamo , 1993 , pp. 157 - 159
Copyright
Copyright © Kluwer 1993 

References

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