TY - JOUR

T1 - Starspot and flare activity of the dwarf system CM Dra

AU - Kozhevnikova, A. V.

AU - Svechnikov, M. A.

AU - Kozhevnikov, V. P.

PY - 2009

Y1 - 2009

N2 - The spotting activity of the dwarf system CM Dra (dM4.5+dM4.5) is analyzed using new photometric observations taken in the spring of 2005 using the multichannel photometer and 70-cm telescope at the Astronomical Observatory of the Urals State University. A light curve constructed for this system revealed a rotational brightness modulation of low amplitude, 0(m).016, owing to cold spots analogous to those on the sun. The longitude of maximum spotting is found to be 263 degrees +/- 4 degrees perpendicular to the line between the centers of the components. A comparison with our earlier observations in 1996-1997, as well as with published data, shows that during different epochs a spotting maximum is observed in the hemisphere of the principal component which faces the secondary component and is shifted by 30 degrees relative to the line between the centers along the direction of rotation of the star. This may indicate a role for tidal effects in creating the magnetic activity of CM Dra. Grouping of flares in time is observed, even for long-term observations. This appears to be related to the passage of large active regions across the star's disk and may indicate a possible cyclical activity of CM Dra.

AB - The spotting activity of the dwarf system CM Dra (dM4.5+dM4.5) is analyzed using new photometric observations taken in the spring of 2005 using the multichannel photometer and 70-cm telescope at the Astronomical Observatory of the Urals State University. A light curve constructed for this system revealed a rotational brightness modulation of low amplitude, 0(m).016, owing to cold spots analogous to those on the sun. The longitude of maximum spotting is found to be 263 degrees +/- 4 degrees perpendicular to the line between the centers of the components. A comparison with our earlier observations in 1996-1997, as well as with published data, shows that during different epochs a spotting maximum is observed in the hemisphere of the principal component which faces the secondary component and is shifted by 30 degrees relative to the line between the centers along the direction of rotation of the star. This may indicate a role for tidal effects in creating the magnetic activity of CM Dra. Grouping of flares in time is observed, even for long-term observations. This appears to be related to the passage of large active regions across the star's disk and may indicate a possible cyclical activity of CM Dra.

UR - https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=tsmetrics&SrcApp=tsm_test&DestApp=WOS_CPL&DestLinkType=FullRecord&KeyUT=000272351000005

UR - http://www.scopus.com/inward/record.url?partnerID=8YFLogxK&scp=71149116375

U2 - 10.1007/s10511-009-9090-4

DO - 10.1007/s10511-009-9090-4

M3 - Article

VL - 52

SP - 512

EP - 522

JO - Astrophysics

JF - Astrophysics

SN - 0571-7256

IS - 4

ER -