2008A&A...487.1163L


C.D.S. - SIMBAD4 rel 1.7 - 2021.03.05CET12:29:07

2008A&A...487.1163L - Astronomy and Astrophysics, volume 487, 1163-1170 (2008/9-1)

Hot Jupiters and stellar magnetic activity.

LANZA A.F.

Abstract (from CDS):

Recent observations suggest that stellar magnetic activity may be influenced by the presence of a close-by giant planet. Specifically, chromospheric hot spots rotating in phase with the planet orbital motion have been observed during some seasons in a few stars harbouring hot Jupiters. The spot leads the subplanetary point by a typical amount of ∼ 60°-70°, with the extreme case of {upsilon} And where the angle is ∼ 170°. The interaction between the star and the planet is described considering the reconnection between the stellar coronal field and the magnetic field of the planet. Reconnection events produce energetic particles that, moving along magnetic field lines, impact onto the stellar chromosphere giving rise to a localized hot spot.A simple magnetohydrostatic model is introduced to describe the coronal magnetic field of the star connecting its surface to the orbiting planet. The field is assumed to be axisymmetric around the rotation axis of the star and its configuration is more general than a linear force-free field.With a suitable choice of the free parameters, the model can explain the phase differences between the hot spots and the planets observed in HD 179949, {upsilon} And, HD 189733, and {tau} Bootis, as well as their visibility modulation on the orbital period and seasonal time scales. The possible presence of cool spots associated with the planets in τ Boo and HD 192263 cannot be explained by the present model. However, we speculate about the possibility that reconnection events in the corona may influence subphotospheric dynamo action in those stars producing localized photospheric (and chromospheric) activity migrating in phase with their planets.

Abstract Copyright:

Journal keyword(s): stars: planetary systems - stars: activity - stars: late-type - stars: magnetic fields - stars: general

Simbad objects: 5

goto Full paper

goto View the reference in ADS

Number of rows : 5

N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2021
#notes
1 * ups And PM* 01 36 47.84216 +41 24 19.6443 4.70 4.64 4.10 3.64 3.35 F9V 902 1
2 * tau Boo Ro* 13 47 15.74340 +17 27 24.8552 5.02 4.98 4.49 4.09 3.85 F7IV-V 901 1
3 HD 179949 BY* 19 15 33.2300861317 -24 10 45.673372382   6.772 6.237     F8V 360 1
4 HD 189733 BY* 20 00 43.7130382888 +22 42 39.071811263 9.241 8.578 7.648 7.126 6.68 K2V 746 1
5 HD 192263 BY* 20 13 59.8455148268 -00 52 00.771665295 9.447 8.724 7.767 7.231 6.771 K1/2V 216 1

    Equat.    Gal    SGal    Ecl

To bookmark this query, right click on this link: simbad:objects in 2008A&A...487.1163L and select 'bookmark this link' or equivalent in the popup menu


2021.03.05-12:29:07

© Université de Strasbourg/CNRS

    • Contact