The winds of young, Solar-type stars in Coma Berenices and Hercules-Lyra. (arXiv:2112.01445v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Evensberget_D/0/1/0/all/0/1">Dag Evensberget</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Carter_B/0/1/0/all/0/1">Bradley D. Carter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marsden_S/0/1/0/all/0/1">Stephen C. Marsden</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Folsom_C/0/1/0/all/0/1">Colin Folsom</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Salmeron_R/0/1/0/all/0/1">Raquel Salmeron</a>
We present wind models of ten young Solar-type stars in the Hercules-Lyra
association and the Coma Berenices cluster aged around 0.26 Gyr and 0.58 Gyr
respectively. Combined with five previously modelled stars in the Hyades
cluster, aged 0.63 Gyr, we obtain a large atlas of fifteen observationally
based wind models. We find varied geometries, multi-armed structures in the
equatorial plane, and a greater spread in quantities such as the angular
momentum loss. In our models we infer variation of a factor of ~6 in wind
angular momentum loss $dot J$ and a factor of ~2 in wind mass loss $dot M$
based on magnetic field geometry differences when adjusting for the unsigned
surface magnetic flux. We observe a large variation factor of ~4 in wind
pressure for an Earth-like planet; we attribute this to variations in the
‘magnetic inclination’ of the magnetic dipole axis with respect to the stellar
axis of rotation. Within our models, we observe a tight correlation between
unsigned open magnetic flux and angular momentum loss. To account for possible
underreporting of the observed magnetic field strength we investigate a second
series of wind models where the magnetic field has been scaled by a factor of
5. This gives $dot M propto B^{0.4}$ and $dot J propto B^{1.0}$ as a result
of pure magnetic scaling.
We present wind models of ten young Solar-type stars in the Hercules-Lyra
association and the Coma Berenices cluster aged around 0.26 Gyr and 0.58 Gyr
respectively. Combined with five previously modelled stars in the Hyades
cluster, aged 0.63 Gyr, we obtain a large atlas of fifteen observationally
based wind models. We find varied geometries, multi-armed structures in the
equatorial plane, and a greater spread in quantities such as the angular
momentum loss. In our models we infer variation of a factor of ~6 in wind
angular momentum loss $dot J$ and a factor of ~2 in wind mass loss $dot M$
based on magnetic field geometry differences when adjusting for the unsigned
surface magnetic flux. We observe a large variation factor of ~4 in wind
pressure for an Earth-like planet; we attribute this to variations in the
‘magnetic inclination’ of the magnetic dipole axis with respect to the stellar
axis of rotation. Within our models, we observe a tight correlation between
unsigned open magnetic flux and angular momentum loss. To account for possible
underreporting of the observed magnetic field strength we investigate a second
series of wind models where the magnetic field has been scaled by a factor of
5. This gives $dot M propto B^{0.4}$ and $dot J propto B^{1.0}$ as a result
of pure magnetic scaling.
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