Awesome Stellar Flare Spectra

Nugget
Number:	128
1st Author:	Adam Kowalski
2nd Author:	Suzanne Hawley
Published:	2010 June1
Next Nugget:	TBD
Previous Nugget:	RHESSI's Anneal Adventure

Introduction

RHESSI observations have abundantly confirmed the close association of hard X-rays with white-light flare emission. But what is the emission mechanism? In principle we could unlimber high-resolution spectrographs and learn a great deal, but for somewhat unclear reasons solar astronomers have pretty much failed to do this and still refer to Hodgson's description of the first-observed solar flare as having "the dazzling brilliancy of the bright star α Lyrae."

So... in the absence of much direct spectroscopic evidence, we need to turn to stellar flares for guidance. One problem on the Sun is to get the spectrograph slit situated on the right part of the Sun at the right time. With stars, there is no problem about "where", just "when", but many flare stars are much more active than the Sun and also produce more powerful flares. We can use these spectra for guidance on the physics of solar flares, with of course the hypothesis that the solar and stellar flare events are fundamentally similar.