%0 Journal Article
%T Mass Loss in Pre-main-sequence Stars via Coronal Mass Ejections and Implications for Angular Momentum Loss
%+ Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112))
%A Aarnio, Alicia N.
%A Matt, Sean P.
%A Stassun, Keivan G.
%< avec comité de lecture
%@ 0004-637X
%J The Astrophysical Journal
%I American Astronomical Society
%V 760
%8 2012
%D 2012
%Z 1209.6410
%Z 2012ApJ...760....9A
%R 10.1088/0004-637X/760/1/9
%K stars: activity
%K stars: evolution
%K stars: mass-loss
%K stars: pre-main sequence
%K stars: solar-type
%K Astrophysics - Solar and Stellar Astrophysics
%Z Sciences of the Universe [physics]Journal articles
%X We develop an empirical model to estimate mass-loss rates via coronal mass ejections (CMEs) for solar-type pre-main-sequence (PMS) stars. Our method estimates the CME mass-loss rate from the observed energies of PMS X-ray flares, using our empirically determined relationship between solar X-ray flare energy and CME mass: log (M CME[g]) = 0.63 × log (E flare[erg]) - 2.57. Using masses determined for the largest flaring magnetic structures observed on PMS stars, we suggest that this solar-calibrated relationship may hold over 10 orders of magnitude in flare energy and 7 orders of magnitude in CME mass. The total CME mass-loss rate we calculate for typical solar-type PMS stars is in the range 10-12-10-9 M ⊙ yr-1. We then use these CME mass-loss rate estimates to infer the attendant angular momentum loss leading up to the main sequence. Assuming that the CME outflow rate for a typical ~1 M ⊙ T Tauri star is <10-10 M ⊙ yr-1, the resulting spin-down torque is too small during the first ~1 Myr to counteract the stellar spin-up due to contraction and accretion. However, if the CME mass-loss rate is >~ 10-10 M ⊙ yr-1, as permitted by our calculations, then the CME spin-down torque may influence the stellar spin evolution after an age of a few Myr.
%G English
%L insu-03621687
%U https://insu.hal.science/insu-03621687
%~ CEA
%~ INSU
%~ UNIV-PARIS7
%~ CNRS
%~ DSM-IRFU
%~ IRFU-AIM
%~ CEA-DRF
%~ UNIV-PARIS
%~ UP-SCIENCES
%~ GS-PHYSIQUE