Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099

Details Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099 Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099

2003-12-09

arxiv.org/abs/astro-ph/0312238v1

Mon.Not.Roy.Astron.Soc. 348 (2004) 1175-1190

Astronomy and Astrophysics

Astrophysics

accepted by MNRAS

Scientific paper

10.1111/j.1365-2966.2004.07420.x

We present here spectropolarimetric observations of the RS CVn system HR 1099 (V711 Tau) secured from 1998 February to 2002 January with the spectropolarimeter MuSiCoS at the Telescope Bernard Lyot (Observatoire du Pic du Midi, France). We apply Zeeman-Doppler Imaging and reconstruct brightness and magnetic surface topologies of the K1 primary subgiant of the system, at five different epochs. We confirm the presence of large, axisymmetric regions where the magnetic field is mainly azimuthal, providing further support to the hypothesis that dynamo processes may be distributed throughout the whole convective zone in this star. We study the short-term evolution of surface structures from a comparison of our images with observations secured at close-by epochs by Donati et al. (2003) at the Anglo-Australian Telescope. We conclude that the small-scale brightness and magnetic patterns undergo major changes within a timescale of 4 to 6 weeks, while the largest structures remain stable over several years. We report the detection of a weak surface differential rotation (both from brightness and magnetic tracers) indicating that the equator rotates faster than the pole with a difference in rotation rate between the pole and the equator about 4 times smaller than that of the Sun. This result suggests that tidal forces also impact the global dynamic equilibrium of convective zones in cool active stars.

Affiliated with

Also associated with

No associations

Rating

Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-40959