Coordinated Millimeter VLBI Array Observations of R Cassiopeiae: 86 GHz SiO Masers and Envelope Dynamics
Publication information:
R. B. Phillips, G. R. Sivakoff, C. J. Lonsdale, and S. S. Doeleman. 2001. “Coordinated Millimeter VLBI Array Observations of R Cassiopeiae: 86 GHz SiO Masers and Envelope Dynamics”. The Astronomical Journal, 122, Pp. 2679-85
Abstract
Coordinated Millimeter VLBI Array measurements at 86 GHz have imaged thesilicon monoxide masers of the nearby red giant R Cassiopeiae at twoepochs separated by approximately 1/12 the stellar pulsation period. Thev=1, J=2-->1 transition comes from a ring at 1.5 to 2 stellar radii.Doppler velocity patterns are ordered over scales up to ~1 AU but arenot consistent with simple models such as global rotation. One majormasing region disappeared in the interval between the two epochs.