International Journal of Astrobiology

Table of Contents - 2010 - Volume 9, Special Issue 04 (Special issue Papers from the Astrobiology Society of Britain Conference 2010)  

Research Article

Spectral line enhancements as signatures for stellar activity: AD Leonis – an example

M. Leitzingera1 c1, P. Oderta1, A. Hanslmeiera1, I. Ribasa2, A.A. Konovalenkoa3, M. Vankoa4, H. Lammera5, M.L. Khodachenkoa5 and H.O. Ruckera5

a1 Institute of Physics/IGAM, University of Graz, Austria

a2 Institut d'Estudis de Espacials de Catalunya, Barcelona, Spain

a3 Institute of Radio Astronomy, Ukrainian Academy of Sciences, Kharkov, Ukraine

a4 Astronomical Institute, Slovak Academy of Sciences, Tatranska Lomnica, Slovakia

a5 Space Research Institute, Austrian Academy of Sciences, Graz, Austria

Abstract

A high level of stellar activity in the form of frequent flaring and frequent mass ejections can lead to the total loss of exoplanetary atmospheres due to evaporation and erosion. Simulations have shown such scenarii for close-in exoplanets orbiting M-stars. Information on stellar flaring activity is accessible more easily than information on stellar mass ejections, simply due to the difference in detection. In the National Aeronautics and Space Administration/Far Ultraviolet Spectroscopic Explorer spectra of the dM star AD Leonis we find an interesting event lasting for only one spectrum. The first component of the OVI (103.19 nm, 103.76 nm) duplet shows an enhancement of the blue wing, shifted by about 90 km s−1. This event occurred one spectrum after a flare. We discuss several solar/stellar phenomena that might produce such a spectral feature and could therefore explain this event.

(Received May 23 2010)

(Accepted July 20 2010)

(Online publication August 19 2010)

Key Words:

Correspondence:

c1 e-mail: martin.leitzinger@uni-graz.at