Search Publications
Accurate fundamental parameters for 23 bright solar-type stars
Butler, R. P.; Carrier, F.; Lo Curto, G. +7 more
We combine results from interferometry, asteroseismology and spectroscopy to determine accurate fundamental parameters of 23 bright solar-type stars, from spectral type F5 to K2 and luminosity classes III-V. For some stars we can use direct techniques to determine the mass, radius, luminosity and effective temperature, and we compare with indirect…
Detection of a magnetic field on HD108: clues to extreme magnetic braking and the Of?p phenomenon
Bouret, J. -C.; Martins, F.; Donati, J. -F. +5 more
We report the detection of a magnetic field on the Of?p star HD108. Spectropolarimetric observations conducted in 2007, 2008 and 2009, respectively, with NARVAL@Télescope Bernard Lyot (TBL) and Echelle SpectroPolarimetric Device for the Observation of Stars at Canada-France-Hawaii Telescope (ESPaDOnS@CFHT) reveal a clear Zeeman signature in the av…
Discovery of a strong magnetic field in the rapidly rotating B2Vn star HR 7355
Manset, N.; Wade, G. A.; Marcolino, W. L. F. +5 more
We report the detection of a strong, organized magnetic field in the He-variable early B-type star HR 7355 using spectropolarimetric data obtained with ESPaDOnS on the 3.6-m Canada-France-Hawaii Telescope within the context of the Magnetism in Massive Stars (MiMeS) Large Program. HR 7355 is both the most rapidly rotating known main-sequence magnet…
Stellar winds and mass loss from extreme helium stars
Hamann, W. -R.; Jeffery, C. S.
Extreme helium stars are very rare low-mass supergiants in a late stage of evolution. They are probably contracting to become white dwarfs following a violent phase of evolution which caused them to become hydrogen-deficient giants, possibly R CrB stars. Using the latest generation of models for spherically expanding stellar atmospheres, we set ou…
A study of the interacting binary V393Scorpii
Mennickent, R. E.; Kołaczkowski, Z.; Graczyk, D. +1 more
We present high-resolution J-band spectroscopy of V393Sco obtained with the Cryogenic High-Resolution Infrared Echelle Spectrograph (CRIRES) at the ESO Paranal Observatory along with a discussion of archival International Ultraviolet Explorer (IUE) spectra and published broad-band magnitudes. The best fit to the spectral energy distribution outsid…
Ultraviolet study of the active interacting binary star R Arae using archival IUE data
Sahade, Jorge; Guinan, Edward F.; Reed, Phillip A. +7 more
The eclipsing and strongly interacting binary star system R Arae (HD 149730) is in a very active and very short-lived stage of its evolution. R Ara consists of a B9V primary and an unknown secondary. We have collected the International Ultraviolet Explorer (IUE) archival data on R Ara, with most of the data being studied for the first time. There …
A far-ultraviolet variability survey of the globular cluster M80
Knigge, C.; Long, K. S.; Zurek, D. R. +2 more
We have searched for variable sources in the core region of M80, using far-ultraviolet (FUV) data taken with the Advanced Camera for Surveys on board the Hubble Space Telescope. We found three sources that exhibit strong signs of variability in our data. Among these is source TDK1, which we believe to be an RRLyrae star that reached maximum bright…
The dense and asymmetric central star wind of the young PN He 2-138
Prinja, R. K.; Urbaneja, M. A.; Massa, D. L. +1 more
We present optical European Southern Observatory time series and UV archival (Far Ultraviolet Spectroscopic Explorer (FUSE), Hubble Space Telescope, International Ultraviolet Explorer) spectroscopy of the H-rich central star of He 2-138. Our study targets the central star wind in a very young planetary nebula, and explores physical conditions that…