Magnetic Fields in the envelopes of late-type stars: Circular Polarization of H2O Masers

W. H. T. Vlemmings; P. J. Diamond; H. J. van Langevelde

doi:10.1007/978-94-010-0139-7_67

paper

Magnetic Fields in the envelopes of late-type stars: Circular Polarization of H2O Masers

arXiv:astro-ph/0208052 · doi:10.1007/978-94-010-0139-7_67

Abstract

We present the first circular polarization measurements of circumstellar water masers around a sample of late-type stars. These observations are used to obtain the magnetic field strength in the water maser region with both an LTE and non-LTE analysis. We find fields from a few hundred milliGauss up to a few Gauss, indicating a solar-type r^(-2) dependence of the magnetic field on the distance. No linear polarization is detected to less than 1%.

4 pages, 2 figure; to be published in: Proceeding of WS on Mass-Losing Pulsating Stars and their Circumstellar Matter, Sendai, Japan, Y.Nakada & M.Honma (eds), Kluwer ASSL series