Direct Ultraviolet Imaging and Spectroscopy of Betelgeuse

Abstract

Direct images of Betelgeuse were obtained over a span of 4 years with the Faint Object Camera on the Hubble Space Telescope. These images reveal the extended ultraviolet continuum emission (about 2 times the optical diameter), the varying overall ultraviolet flux levels and a pattern of bright surface continuum features that change in position and appearance over several months or less. Concurrent photometry and radial velocity measures support the model of a pulsating star, first discovered in the ultraviolet from IUE. Spatially resolved HST spectroscopy reveals a larger extention in chromospheric emissions of Mg II as well as the rotation of the supergiant. Changing localized subsonic flows occur in the low chromosphere that can cover a substantial fraction of the stellar disk and may initiate the mass outflow.

9 pages, 5 figures, Betelgeuse Workshop, November 2012, Paris. To be published in the European Astronomical Society Publications Series, 2013, Editors: Pierre Kervella, Thibaut Le Bertre & Guy Perrin

References in corpus (2)

• Fundamental parameters of Cepheids. V. Additional photometry and radial velocity for southern Cepheids
• Spatially Resolved STIS Spectroscopy of alpha Orionis: Evidence for Non-radial Chromospheric Oscillation from Detailed Modeling

Cited by in corpus (6)

• The close circumstellar environment of Betelgeuse - V. Rotation velocity and molecular envelope properties from ALMA
• The Photospheric Temperatures of Betelgeuse during the Great Dimming of 2019/2020: No New Dust Required
• Spatially Resolved Ultraviolet Spectroscopy of the Great Dimming of Betelgeuse
• The Great Dimming of Betelgeuse: a Surface Mass Ejection (SME) and its Consequences
• Temporal Evolution of the Size and Temperature of Betelgeuse's Extended Atmosphere
• Betelgeuse, the Prototypical Red Supergiant