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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

MOBSTER - III. HD62658: a magnetic Bp star in an eclipsing binary with a non-magnetic `identical twin'

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Shultz, M. E. [1] ; Johnston, C. [2] ; Labadie-Bartz, J. [3] ; Petit, V. [1] ; David-Uraz, A. [1] ; Kochukhov, O. [4] ; Wade, G. A. [5] ; Pepper, J. [6] ; Stassun, K. G. [7, 8] ; Rodriguez, J. E. [9] ; Lund, M. B. [10] ; James, D. J. [9, 11]
Total Authors: 12
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[1] Univ Delaware, Dept Phys & Astron, 217 Sharp Lab, Newark, DE 19716 - USA
[2] Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven - Belgium
[3] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, BR-05508900 Sao Paulo, SP - Brazil
[4] Uppsala Univ, Dept Phys & Astron, Box 516, SE-75120 Uppsala - Sweden
[5] Royal Mil Coll Canada, Dept Phys & Space Sci, Kingston, ON K7K 7B4 - Canada
[6] Lehigh Univ, Dept Phys, 16 Mem Dr East, Bethlehem, PA 18015 - USA
[7] Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 - USA
[8] Fisk Univ, Dept Phys, 1000 17th Ave North, Nashville, TN 37208 - USA
[9] Harvard & Smithsonian, Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 - USA
[10] NASA, Caltech IPAC, Exoplanet Sci Inst, 1200 E Calif Ave, Pasadena, CA 91125 - USA
[11] Harvard Univ, Black Hole Initiat, 20 Garden St, Cambridge, MA 02138 - USA
Total Affiliations: 11
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 490, n. 3, p. 4155-4166, DEC 2019.
Web of Science Citations: 0

HD62658 (B9p V) is a little-studied chemically peculiar star. Light curves obtained by the Kilodegree Extremely Little Telescope (KELT) and Transiting Exoplanet Survey Satellite (TESS) show clear eclipses with a period of about 4.75 d, as well as out-of-eclipse brightness modulation with the same 4.75 d period, consistent with synchronized rotational modulation of surface chemical spots. High-resolution ESPaDOnS circular spectropolarimetry shows a clear Zeeman signature in the line profile of the primary; there is no indication of a magnetic field in the secondary. PHOEBE modelling of the light curve and radial velocities indicates that the two components have almost identical masses of about 3 M-circle dot. The primary's longitudinal magnetic field < B-z > varies between about +100 and -250 G, suggesting a surface magnetic dipole strength B-d = 850 G. Bayesian analysis of the Stokes V profiles indicates B-d = 650 G for the primary and B-d < 110 G for the secondary. The primary's line profiles are highly variable, consistent with the hypothesis that the out-of-eclipse brightness modulation is a consequence of rotational modulation of that star's chemical spots. We also detect a residual signal in the light curve after removal of the orbital and rotational modulations, which might be pulsational in origin; this could be consistent with the weak line profile variability of the secondary. This system represents an excellent opportunity to examine the consequences of magnetic fields for stellar structure via comparison of two stars that are essentially identical with the exception that one is magnetic. The existence of such a system furthermore suggests that purely environmental explanations for the origin of fossil magnetic fields are incomplete. (AU)

FAPESP's process: 17/23731-1 - Analysis and Modeling of a Large Sample of Galactic Be Stars
Grantee:Jonathan Michael Labadie-Bartz
Support type: Scholarships in Brazil - Post-Doctorate