48 citations · 136 across the 8 of their papers we have counts for
9 papers
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…
The Discovery of 25 um Interstellar Methanol
Sarah L. Nickerson, Naseem Rangwala, Keeyoon Sung +15
We present the first astrophysical detection of methanol (CH3OH) in the torsional band near 25 um. Using high resolution mid-infrared (MIR) spectroscopy, we identified over seventy…
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…
ALMA Observations of Anisotropic Dust Mass-loss in the Inner Circumstellar Environment of the Red Supergiant VY Canis Majoris
E. O'Gorman, W. Vlemmings, A. M. S. Richards +8
The processes leading to dust formation and the subsequent role it plays in driving mass loss in cool evolved stars is an area of intense study. Here we present high resolution ALM…
ALMA sub-mm maser and dust distribution of VY Canis Majoris
A. M. S. Richards, C. M. V. Impellizzeri, E. M. Humphreys +25
Cool, evolved stars have copious, enriched winds. The structure of these winds and the way they are accelerated is not well known. We need to improve our understanding by studying…
Water Vapor on Betelgeuse as Revealed by TEXES High-Resolution 12 Micron Spectra
N. Ryde, G. M. Harper, M. J. Richter +2
The outer atmosphere of the M supergiant Betelgeuse is puzzling. Published observations of different kinds have shed light on different aspects of the atmosphere, but no unified pi…