HD 62525

Spot modelling of the flare M4.5 dwarf YZ CMi We report on a photometric study of the flare M4.5 dwarf YZ CMi as basedon photoelectric observations from the seasons 1972/73, 1979/80 and1996/97. We suggest spot activity to explain the light and colourcurves. Spots are generally 500K cooler than the surrounding photosphereand there are basically two solutions available for the observations:high latitude spot changing slightly basic properties such as radius andlatitude or active near-equatorial (belt-like) centers represented bythree spots. However, the activity centers changed in longitudes(180o). The typical spot coverage (inclinationi=60o) is 10-15% and 5% for the season 1996/97 or 25%for the stellar inclination i=75o. As a by-product, V curveand (V-I) and (V-K) indexes turn out to be most promising in modellingof M-type stars as far as present calibrations are concerned.
Monitoring of spotted RS CVn and BY Dra type stars. I. Simultaneous optical and infrared photometry UBV(RI)cJHK photometry of 6 active stars, collected at theSouth African Astronomical Observatory in 1996 and 1997, is presented.The light and colour curves, which are compared with those observed atprevious epochs, show significant variation in their wave-likemodulation and in their maximum brightness.
Coordinated Ultraviolet, Optical and Radio Observations of RS CVn and Flare Stars Not Available

WIKISKY.ORG