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Related papers: Zeeman Doppler Imaging of ksi Boo A and B

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In this paper we describe and evaluate new spectral line polarisation observations obtained with the goal of mapping the surfaces of magnetic Ap stars in great detail. One hundred complete or partial Stokes IQUV sequences, corresponding to…

Solar and Stellar Astrophysics · Physics 2015-06-05 J. Silvester , G. A. Wade , O. Kochukhov , S. Bagnulo , C. P. Folsom , D. Hanes

Magnetic field investigations of Sun-like stars, using Zeeman splitting of non-polarised spectra, in the optical and H-band have found significantly different magnetic field strengths for the same stars, the cause of which is currently…

Magnetic fields are ubiquitous in active cool stars but they are in general complex and weak. Current Zeeman Doppler imaging (ZDI) studies of cool star magnetic fields chiefly employ circular polarization observations because linear…

Solar and Stellar Astrophysics · Physics 2015-06-03 Lisa Rosén , Oleg Kochukhov , Gregg A. Wade

The early B-type star tau Sco exhibits an unusually complex, relatively weak surface magnetic field. Its topology was previously studied with the Zeeman Doppler imaging (ZDI) modelling of high-resolution circular polarisation (Stokes V)…

Solar and Stellar Astrophysics · Physics 2016-02-03 O. Kochukhov , G. A. Wade

Zeeman-Doppler imaging (ZDI) is used to study the surface magnetic field topology of stars, based on high-resolution spectropolarimetric time series observations. Multiple ZDI inversions have been conducted for the early B-type star tau…

Solar and Stellar Astrophysics · Physics 2025-07-02 Jennifer Rosina Andersson , Oleg Kochukhov , Zheng Zhao , Jens Sjölund

Aims. We aim to investigate the long-term temporal evolution of the magnetic field of the solar-type star \xi Bootis A, both from direct magnetic field measurements and from the simultaneous estimate of indirect activity indicators.…

The observation of the polarization emerging from a rotating star at different phases opens up the possibility to map the magnetic field in the stellar surface thanks to the well-known Zeeman Doppler Imaging. When the magnetic field is…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. J. Martínez González , A. Asensio Ramos

Strong organized magnetic fields have been studied in the upper main sequence chemically peculiar stars for more than half a century. However, only recently have observational methods and numerical techniques become sufficiently mature to…

Solar and Stellar Astrophysics · Physics 2015-05-18 O. Kochukhov , G. A. Wade

Information about stellar magnetic field topologies is obtained primarily from high-resolution circular polarisation (Stokes $V$) observations. Due to their generally complex morphologies, the stellar Stokes $V$ profiles are usually…

Solar and Stellar Astrophysics · Physics 2015-07-29 O. Kochukhov

By studying young magnetically active late-type stars, i.e. analogues to the young Sun, one can draw conclusions on the evolution of the solar dynamo. We determine the topology of the surface magnetic field and study the relation between…

Solar and Stellar Astrophysics · Physics 2016-03-02 Thomas Hackman , Jyri Lehtinen , Lisa Rosén , Oleg Kochukhov , Maarit J. Käpylä

We present updated magnetic field maps of the chemically peculiar B9p star $\alpha^2$ CVn created using a series of time resolved observations obtained using the high resolution spectropolarimeters ESPaDOnS and Narval. We compare these new…

Solar and Stellar Astrophysics · Physics 2015-06-18 J. Silvester , O. Kochukhov , G. A. Wade

Historically, the magnetic field geometries of the chemically peculiar Ap stars were modelled in the context of a simple dipole field. However, with the acquisition of increasingly sophisticated diagnostic data, it has become clear that the…

Astrophysics · Physics 2007-12-12 J. Silvester , G. A. Wade , O. Kochukhov , J. D. Landstreet , S. Bagnulo

Plaskett's "star" appears to be one of a small number of short-period binary systems known to contain a hot, massive, magnetic star. Building on the 2013 discovery investigation, we combine an extensive spectropolarimetric (Stokes $V$)…

Solar and Stellar Astrophysics · Physics 2022-04-06 J. H. Grunhut , G. A. Wade , C. P. Folsom , C. Neiner , O. Kochukhov , E. Alecian , M. Shultz , V. Petit , the MiMeS , BinaMIcS collaborations

Aims: We present a magnetic Doppler imaging study from all Stokes parameters of the cool, chemically peculiar star HD 24712. This is the very first such analysis performed at a resolving power exceeding 10^5. Methods: The analysis is…

Solar and Stellar Astrophysics · Physics 2015-01-14 N. Rusomarov , O. Kochukhov , T. Ryabchikova , N. Piskunov

We investigate the magnetic geometry of the active G8 dwarf xi Bootis A, from spectropolarimetric observations obtained in 2003 with the MuSiCoS echelle spectropolarimeter at the Telescope Bernard Lyot (Observatoire du Pic du Midi, France).…

Previous studies have related surface temperature maps, obtained with the Doppler imaging (DI) technique, of LQ Hya with long-term photometry. We compare surface magnetic field maps, obtained with the Zeeman Doppler imaging (ZDI) technique,…

Magnetic Doppler imaging from four Stokes parameter observations has uncovered a new level of complexity of stellar magnetic fields previously not known. This new information is of interest to the evolution and structure of magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-22 N. Rusomarov , O. Kochukhov , N. Piskunov

We have observed the active star $\xi$ Boo A (HD 131156A) with high precision broadband linear polarimetry contemporaneously with circular spectropolarimetry. We find both signals are modulated by the 6.43 day rotation period of $\xi$ Boo…

We have obtained high resolution spectropolarimetric data for the planet-hosting star $\tau$ Bootis, using the ESPaDOnS spectropolarimeter at CFHT. A weak but clear Stokes $V$ signature is detected on three of the four nights of June 2006…

Astrophysics · Physics 2009-11-11 C. Catala , J. -F. Donati , E. Shkolnik , D. Bohlender , E. Alecian

We study the fast rotating M5 giant EK Boo by means of spectropolarimetry to obtain direct and simultaneous measurements of both the magnetic field and activity indicators, in order to infer the origin of the activity in this fairly evolved…

Solar and Stellar Astrophysics · Physics 2015-05-19 R. Konstantinova-Antova , M. Auriere , C. Charbonnel , N. A. Drake , K. -P. Schroeder , I. Stateva , E. Alecian , P. Petit , R. Cabanac
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