ForumSpringerAstron. Astrophys.
ForumWhats NewSearchOrders

Astron. Astrophys. 327, 1114-1122

Table of Contents
Available formats: HTML | PDF | (gzipped) PostScript

Long-term photometric flares patrol (1967-1977) on EV Lacertae: a clear evidence of a longitude concentrated flaring activity
in 1970*,**

G. Leto1, I. Pagano2, C.S. Buemi3, and M. Rodonò2,3

1Istituto di Radioastronomia C.N.R., Stazione VLBI, I-96017 Noto (SR), Italy
2Osservatorio Astrofisico di Catania, Viale A. Doria 6, I-95125 Catania, Italy
3Istituto di Astronomia, Università di Catania, Viale A. Doria 6, I-95125 Catania, Italy

Received 10 April 1997 / Accepted 24 April 1997


We report on a large sample of homogeneous photoelectric data obtained by monitoring the red dwarf flare star EV Lac. The data were collected in 10 years (1967-77) at Catania Astrophysical Observatory on Mt. Etna and consist of 212, 170, and 128 flares detected in the U, B and V band during total monitoring times of 903, 1013, and 864 hours, respectively.

The peak luminosity, the total energy emitted, the rise and decay times were measured for each flare. A statistical analysis of this data sample is presented.

A well defined phase modulation of the normalized flare occurrence rate in 1970 clearly suggests that, at that time, on EV Lac flaring activity was concentrated at a preferred longitude.

Key words: stars: EV Lac - stars: flare; activity; rotation

*Based on observations collected at the ``M.G. Fracastoro'' mountain station of Catania Astrophysical Observatory, Italy
**Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( or via http://cdsweb.u-strasbg.fr/Abstract.html

Send offprint requests to: G. Leto (gleto@ira.noto.cnr.it)

© European Southern Observatory (ESO) 1997

Online publication: October 20, 1997
Last change: April 6, 1998