VLBA12B-330

DETERMINING THE NATURE OF THE 20-40 GHZ RADIO EMISSION FROM ACTIVE M DWARFS

Abstract

Quiescent radio emission from active stars in the 1-15 GHz frequency range was discovered in the early days of the VLA. Recent EVLA observations have now confirmed the detection of a new, brighter, high frequency component (> 20 GHz) in the radio emission from two main sequence active M dwarfs. Determining the nature of this emission is crucial if the diagnostic potential of this new observing window is to be realized. One of these stars is the well characterized flare star UV Ceti. We propose to conduct HSA [VLBA+GBT] observations of UV Ceti, switching between 8.4 and 23.8 GHz, to constrain the brightness temperature and hence the nature of the high frequency component of emission, while simultaneously localizing its position relative to the lower frequency component. A possible exciting end product from this campaign would be the first resolved image of the thermal corona of a main sequence star, other than the Sun. Four observations of 2 hours each are requested. Total request is 8 hours.

Investigators

Name	Institution
Gregg Hallinan *	National Radio Astronomy Observatory; California at Berkeley, University of; California Institute of Technology
Stephen Bourke	Joint Institute for Very Long Baseline Interferometry European Research Infrastructure Consortium; Galway, National University of Ireland; Chalmers University of Technology; California Institute of Technology
Michael Rupen	Herzberg Astronomy & Astrophysics Research Centre, National Research Council Canada

* indicates the PI