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| Paper: |
Extreme Coronal Mass Ejections in Young Low-Mass Stars |
| Volume: |
448, 16th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun |
| Page: |
43 |
| Authors: |
Aarnio, A. N.; Stassun, K. G.; Matt, S. P.; Hughes, W. J.; McGregor, S. L. |
| Abstract: |
Two long-standing questions in the study of young, low-mass stars are: (1) What are the
mechanisms that govern the observed order-of-magnitude decrease of stellar angular momentum
during pre-main-sequence evolution, and (2) What are the physical drivers of X-ray production
in these stars at up to 104 times the solar value? Application of solar flare models to the most
powerful X-ray flares observed among T Tauri stars in Orion suggests that the flares are
produced by magnetic loop structures with lengths of up to tens of stellar radii. We present new
results demonstrating that, for the majority of these stars, the extremely large flaring structures
are not anchored to or stabilized by circumstellar disks. Given the energy and size scales involved,
mass losses (e.g., via stellar coronal mass ejections—CMEs—associated with these flares) at such
large effective lever arms could shed substantial angular momentum. To begin estimating the attendant
angular momentum losses of such extreme CMEs in young stars, we have assembled from the
solar literature a database of ∼10,000 X-ray flares and CMEs, from which we determine for the
first time the empirical relationship between solar X-ray flare energy and CME ejected mass.
Finally, we demonstrate how our flare flux/CME mass relationship can be used to estimate
stellar angular momentum loss via extreme CMEs in young stars. |
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