An "A star" on an M star during a flare within a flare

被引：7

作者：

Kowalski, Adam F. ^{[1
]}

Hawley, Suzanne L. ^{[1
]}

Holtzman, Jon A.

Wisniewski, John P. ^{[1
]}

Hilton, Eric J. ^{[1
]}

机构：

[1] Univ Washington, Dept Astron, Seattle, WA 98195 USA

来源：

PHYSICS OF SUN AND STAR SPOTS | 2011年 / 273期

关键词：

Physical data and processes: radiative transfer; astronomical methods: numerical; atmospheric effects; techniques: spectroscopic; stars: atmospheres; stars: flare; stars: late-type; MULTIWAVELENGTH OBSERVATIONS; MODELS;

D O I：

10.1017/S1743921311015341

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

M dwarfs produce explosive flare emission in the near-UV and optical continuum, and the mechanism responsible for this phenomenon is not well-understood. We present a near-UV/optical flare spectrum from the rise phase of a secondary flare, which occurred during the decay of a much larger flare. The newly formed flare emission resembles the spectrum of an early-type star, with the Balmer lines and continuum in absorption. We model this observation phenomenologically as a temperature bump (hot spot) near the photosphere of the M dwarf. The amount of heating implied by our model (Delta T-phot similar to 16,000 K) is far more than predicted by chromospheric backwarming in current 1D RHD flare models (Delta T-phot similar to 1200 K).

引用

页码：261 / 264

页数：4