5 papers · 1 filter
ALMA high resolution observations of Betelgeuse: Persistent structure spanning the inner atmosphere
W. R. F. Dent, A. M. S. Richards, G. M. Harper +2
The extended atmosphere of red supergiants (RSGs) forms an important link in the process of mass loss and the subsequent enrichment of the interstellar medium. Large-scale convecti…
HST observations of chromospheric UV lines in the AGB star R Leo
Maryam Saberi, Donald G. Luttermoser, Graham M. Harper +3
The role of stellar chromospheres in the chemistry, mass loss, and evolution of cool evolved stars remains poorly understood. We present high-resolution ultraviolet spectra of the…
Radial Velocity and Astrometric Evidence for a Close Companion to Betelgeuse
Morgan MacLeod, Sarah Blunt, Robert J. De Rosa +10
We examine a century of radial velocity, visual magnitude, and astrometric observations of the nearest red supergiant, Betelgeuse, in order to reexamine the century-old assertion t…
Resolving Red Giant Winds with the Hubble Space Telescope
Brian E. Wood, Graham M. Harper, Hans-Reinhard Mueller
We describe recent spectroscopic observations of red giant stars made by the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope, which have…
Detection of Rydberg lines from the atmosphere of Betelgeuse
W. R. F. Dent, G. Harper, A. M. S. Richards +2
Emission lines from Rydberg transitions are detected for the first time from a region close to the surface of Betelgeuse. The H30 line is observed at 231.905 GHz, with a FWHM ~4…