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Related papers: MOST Observations of sigma Ori E: Challenging the …

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Sigma Ori E (HD 37479) is the prototypical helium-strong star shown to harbor a strong magnetic field, as well as a magnetosphere consisting of two clouds of plasma. The observed optical (ubvy) light curve of sigma Ori E is dominated by…

Solar and Stellar Astrophysics · Physics 2015-06-22 M. E. Oksala , O. Kochukhov , J. Krtička , M. Prvák , Z. Mikulášek

We attempt to characterize the observed variability of the magnetic helium-strong star sigma Ori E in terms of a recently developed rigidly rotating magnetosphere model. This model predicts the accumulation of circumstellar plasma in two…

Astrophysics · Physics 2011-05-12 R. H. D. Townsend , S. P. Owocki , D. Groote

I review the basic concepts of the Rigidly Rotating Magnetosphere model for the circumstellar plasma distribution around the helium-strong star sigma Ori E. I demonstrate that the model can furnish a good fit to the photometric,…

Astrophysics · Physics 2007-05-23 Rich Townsend

This paper presents results obtained from Stokes I and V spectra of the B2Vp star sigma Ori E, observed by both the Narval and ESPaDOnS spectropolarimeters. Using Least- Squares Deconvolution, we investigate the longitudinal magnetic field…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. E. Oksala , G. A. Wade , R. H. D Townsend , O. Kochukhov , S. Owocki

We present new UBVRI observations of the magnetic Bp star sigma Ori E. The basic features of the star's lightcurve have not changed since the previous monitoring by Hesser et al. (1977), indicating that the star's magnetosphere has remained…

Astrophysics · Physics 2007-05-23 Mary Oksala , Rich Townsend

We present new U-band photometry of the magnetic Helium-strong star Sigma Ori E, obtained over 2004-2009 using the SMARTS 0.9-m telescope at Cerro Tololo Inter-American Observatory. When combined with historical measurements, these data…

Solar and Stellar Astrophysics · Physics 2015-05-18 R. H. D. Townsend , M. E. Oksala , D. H. Cohen , S. P. Owocki , A. ud-Doula

Strongly magnetic, rapidly rotating B-type stars with relatively weak winds form centrifugal magnetospheres (CMs), as the stellar wind becomes magnetically confined above the Kepler co-rotation radius. Approximating the magnetic field as a…

Solar and Stellar Astrophysics · Physics 2022-02-16 I. D. Berry , S. P. Owocki , M. E. Shultz , A. ud-Doula

Magnetospheric clouds have been proposed as explanations for depth-varying dips in the phased light curves of young, magnetically active stars such as $\sigma$ Ori E and RIK-210. However, the stellar theory that first predicted…

Sigma Ori E, a massive helium B-type star, shows a high surface rotation and a strong surface magnetic field potentially challenging the process of wind magnetic braking. The Gaia satellite provides an accurate distance to that star and…

Solar and Stellar Astrophysics · Physics 2022-01-12 H. F. Song , G. Meynet , A. Maeder , N. Mowlavi , S. R. Stroud , Z. Keszthelyi , S. Ekstrom , P. Eggenberger , C. Georgy , G. A. Wade , Y. Qin

The initial success of the Rigidly Rotating Magnetosphere (RRM) model application to the B2Vp star sigma OriE by Townsend, Owocki & Groote (2005) triggered a renewed era of observational monitoring of this archetypal object. We utilize…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. E. Oksala , O. Kochukhov , J. Krticka , R. H. D. Townsend , G. A. Wade , M. Prvak , Z. Mikulasek , J. Silvester , S. P. Owocki

We present a semi-analytical approach for modeling circumstellar emission from rotating hot stars with a strong dipole magnetic field tilted at an arbitrary angle to the rotation axis. By assuming the rigid-field limit in which material…

Astrophysics · Physics 2011-05-12 R. H. D. Townsend , S. P. Owocki

Rapidly rotating early-type stars with strong magnetic fields frequently show H$\alpha$ emission originating in Centrifugal Magnetospheres (CMs), circumstellar structures in which centrifugal support due to magnetically enforced corotation…

We present 2D MHD simulations of the radiatively driven outflow from a rotating hot star with a dipole magnetic field aligned with the star's rotation axis. We focus primarily on a model with moderately rapid rotation (half the critical…

Astrophysics · Physics 2011-05-12 A. ud-Doula , R. H. D. Townsend , S. P. Owocki

A team involved in APOGEE, one of the Sloan Digital Sky Survey III programs, recently announced the discovery of two rare rigidly rotating magnetosphere stars, HD345439 and HD23478. Near-infrared spectra of these objects revealed…

Solar and Stellar Astrophysics · Physics 2017-04-05 S. Hubrig , A. F. Kholtygin , M. Schöller , I. Ilyin

In the subset of luminous, early-type stars with strong, large-scale magnetic fields and moderate to rapid rotation, material from the star's radiatively driven stellar wind outflow becomes trapped by closed magnetic loops, forming a…

Solar and Stellar Astrophysics · Physics 2017-12-27 Stanley P. Owocki , Steven R. Cranmer

Recent XMM-Newton observations of the B2 type star rho Oph A indicated a periodicity of 1.205d, which was ascribed to rotational modulation. Since variability of X-ray emission in massive stars is frequently the signature of a magnetic…

Solar and Stellar Astrophysics · Physics 2018-07-18 S. Hubrig , M. Schöller , S. P. Järvinen , M. Küker , A. F. Kholtygin , P. Steinbrunner

We have obtained 18 new high-resolution spectropolarimetric observations of the B2Vp star sigma Ori E with both the Narval and ESPaDOnS spectropolarimeters. The aim of these observations is to test, with modern data, the assumptions of the…

Solar and Stellar Astrophysics · Physics 2015-05-30 M. E. Oksala , G. A. Wade , R. H. D. Townsend , S. P. Owocki , O. Kochukhov , C. Neiner , E. Alecian , J. Grunhut , the MiMeS Collaboration

In this paper we present new and archive radio measurements obtained with the Very Large Array of the magnetic chemically peculiar (MCP) star \sigma Ori E. The radio data have been obtained at different frequencies and are well distributed…

Solar and Stellar Astrophysics · Physics 2015-06-04 P. Leto , C. Trigilio , C. S. Buemi , F. Leone , G. Umana

Photometric observations obtained by the MOST satellite were used to characterize optical small scale variability of the young stars FU Ori and Z CMa. Wavelet analysis for FU Ori reveals the possible existence of several 2-9 d…

Strongly magnetic B-type stars with moderately rapid rotation form `centrifugal magnetospheres' (CMs), from the magnetic trapping of stellar wind material in a region above the Kepler co-rotation radius. A longstanding question is whether…

Solar and Stellar Astrophysics · Physics 2020-10-28 Stanley P. Owocki , Matt E. Shultz , Asif ud-Doula , Jon O. Sundqvist , Richard H. D. Townsend , Steven R. Cranmer
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