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arXiv · 1304.2780

Direct Ultraviolet Imaging and Spectroscopy of Betelgeuse

A. K. Dupree·R. P. Stefanik
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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.

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A. K. Dupree, R. P. Stefanik. 2013-04-09. Direct Ultraviolet Imaging and Spectroscopy of Betelgeuse. https://doi.org/10.1051/eas%2F1360008

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