THOR 42: A Test of Magnetic Models for Pre-main-sequence Stars

Abstract Precise masses and radii have been reported by Murphy et al. for the components of THOR 42 binary. provide evidence that, in their opinion, supports an earlier suggestion Bell that is a member 32 Ori moving group, which, according to al., has age about 24 Myr. From positions 2 mass–radius diagram (MRD), derive ages 22–26 Myr using standard (nonmagnetic) models. However, they also find these models cannot simultaneously reproduce observed masses, radii, effective temperatures, luminosities assumed coeval components. Their Hertzsprung–Russell (HRD) are found be 2–4 times younger than MRD ages, determined from HRD ∼50% smaller dynamical masses. Here, we attempt replicate precise global properties applying model magnetoconvection. We isochrones lead consistent provided surface magnetic fields strengths 300–400 G. our yield vicinity 40 If this estimate correct, it could call into question membership group.