2013ApJ...764..170D


Query : 2013ApJ...764..170D

2013ApJ...764..170D - Astrophys. J., 764, 170 (2013/February-3)

Implications of mass and energy loss due to coronal mass ejections on magnetically active stars.

DRAKE J.J., COHEN O., YASHIRO S. and GOPALSWAMY N.

Abstract (from CDS):

Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 Å flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE –α. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of α and are very large: {dot}M ∼ 5x10–10 M☉/yr and {dot}E ∼0.1 L☉. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence ≳ 1031 erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10–3 LbolX-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of Lbol, the CME mass loss rate is about 5 x10–11 M☉/yr.

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Journal keyword(s): stars: flare - stars: winds, outflows - Sun: coronal mass ejections, CMEs - X-rays: stars

Simbad objects: 4

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Number of rows : 4
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2026
#notes
1 * 47 Cas ** 02 05 07.4242273 +77 16 52.824198   5.590 5.268     F0Vn 128 1
2 * kap01 Cet BY* 03 19 21.6964175772 +03 22 12.714979884 5.71 5.52 4.85 4.27 3.91 G5V 948 0
3 * pi.01 UMa BY* 08 39 11.7046112880 +65 01 15.263122512 6.33 6.26 5.64 5.12 4.79 G0.5V 608 0
4 V* EK Dra BY* 14 39 00.2104038120 +64 17 29.979649860   8.243 7.604     G5VFe-0.7CH-1(k) 500 0

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