Search Publications
HR 5907: Discovery of the most rapidly rotating magnetic early B-type star by the MiMeS Collaboration
Rivinius, Th.; Wade, G. A.; Bohlender, D. A. +14 more
We report the discovery and analysis of a very strong magnetic field in the rapidly rotating early B-type star HR 5907, based on observations obtained as part of the Magnetism in Massive Stars (MiMeS) project. We infer a rotation period of 0.508 276+0.000 015-0.000 012 d from photometric and Hα EW measurements, making this th…
Investigating the spectroscopic, magnetic and circumstellar variability of the O9 subgiant star HD 57682
Kaper, L.; Rivinius, Th.; Ribeiro, J. +12 more
The O9IV star HD 57682, discovered to be magnetic within the context of the Magnetism in Massive Stars (MiMeS) survey in 2009, is one of only eight convincingly detected magnetic O-type stars. Among this select group, it stands out due to its sharp-lined photospheric spectrum. Since its discovery, the MiMeS Collaboration has continued to obtain sp…
IC 4663: the first unambiguous [WN] Wolf-Rayet central star of a planetary nebula
Crowther, P. A.; De Marco, O.; Miszalski, B. +4 more
We report on the serendipitous discovery of the first central star of a planetary nebula (PN) that mimics the helium- and nitrogen-rich WN sequence of massive Wolf-Rayet (WR) stars. The central star of IC 4663 (PN G346.2-08.2) is dominated by broad He II and N V emission lines which correspond to a [WN3] spectral type. Unlike previous [WN] candida…
HST/STIS spectroscopy of the magnetic Of?p star HD 108: the low state at ultraviolet wavelengths
Bouret, J. -C.; Howarth, I. D.; Hillier, D. J. +6 more
We present the first ultraviolet spectrum of the peculiar, magnetic Of?p star HD 108 obtained in its spectroscopic low state. The new data, obtained with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope, reveal significant changes compared to IUE spectra obtained in the high state: N Vλ1240, Si IVλ1400 and C IVλ1550 pr…
Electron optical depths and temperatures of symbiotic nebulae from Thomson scattering
Skopal, A.; Sekeráš, M.
Symbiotic binaries are comprised of nebulae, whose densest portions have electron concentrations of 108-1012 cm-3 and extend to a few astronomical units. They are optically thick enough to cause a measurable effect of the scattering of photons on free electrons. In this paper, we model the extended wings of strong …
The unseen population of F- to K-type companions to hot subdwarf stars
Gänsicke, B. T.; Heber, U.; Breedt, E. +6 more
We present a method to select hot subdwarf stars with A- to M-type companions using photometric selection criteria. We cover a wide range in wavelength by combining Galaxy Evolution Explorer (GALEX) ultraviolet data, optical photometry from the Sloan Digital Sky Survey (SDSS) and the Carlsberg Meridian Telescope, near-infrared data from Two-Micron…
Ultraviolet variability of the helium-peculiar star a Centauri
Sokolov, N. A.
The spectrophotometric variability of the classical magnetic chemically peculiar star a Cen in the ultraviolet spectral region from 1150 to 3100 Å is investigated. This study is based on archival International Ultraviolet Explorer data obtained at various phases of the rotational cycle. The light variations in wavelengths shorter than λ1616 Å are …