6 papers
Semi-empiric Radiative Transfer Modeling of FUSE Stellar Spectra
A. Lobel, E. H. Avrett, J. P. Aufdenberg
We present an overview of radiative transfer modeling efforts to interpret spectra of a variety of stellar objects observed with FUSE. Detailed radiative transfer modeling of high…
Spatially Resolved STIS Spectra of Betelgeuse's Upper Chromosphere and Circumstellar Dust Envelope
A. Lobel
The Hubble Space Telescope observed red supergiant Betelgeuse with the Space Telescope Imaging Spectrograph to investigate the outer atmosphere from spatially resolved spectra. We…
Spatially Resolved STIS Spectroscopy of Betelgeuse's Outer Atmosphere
A. Lobel, J. Aufdenberg, A. K. Dupree +3
We present spatially resolved spectra observed with HST-STIS of the upper chromosphere and dust envelope of Alpha Orionis (M2 Iab). In the fall of 2002 a set of five high-resolutio…
The Millennium Outburst of the Cool Hypergiant Rho Cassiopeiae: Spectroscopy and Modeling
A. Lobel, A. K. Dupree, R. P. Stefanik +7
Between 2000 June and September an exceptional variability phase occurred in the peculiar F-type hypergiant Rho Cas, when the V-brightness dimmed by at least a full magnitude. The…
Chromospheric Dynamics of Betelgeuse from STIS Spectra
Alex Lobel
We present a high-resolution spectral analysis of Betelgeuse (M2 Iab). Between 1998 January and 1999 March four spatially resolved raster scans (http://cfa-www.harvard.edu/cfa/ep/p…
Two Decades of Hypergiant Research
Alex Lobel
This article is a brief review of the research by Dr. C. de Jager and co-workers over the past twenty years into the physics of hypergiant atmospheres. Various important results on…