Detection of a centrifugal magnetosphere in one of the most massive stars in the ρOph star-forming cloud

被引：1
作者：
Hubrig, S. [1 ]
Schoeller, M. [2 ]
Jaervinen, S. P. [1 ]
Kueker, M. [1 ]
Kholtygin, A. F. [3 ]
Steinbrunner, P. [4 ]
机构：
[1] Leibniz Inst Astrophys Potsdam AIP, Sternwarte 16, D-14482 Potsdam, Germany
[2] European Southern Observ, Garching, Germany
[3] St Petersburg State Univ, Astron Inst, St Petersburg, Russia
[4] Free Univ Berlin, Berlin, Germany
来源：
ASTRONOMISCHE NACHRICHTEN | 2018年 / 339卷 / 01期
关键词：
stars: early-type; stars: formation; stars: individual: Oph A; stars: magnetic field; stars: variables: general; stars: X-rays; DRIVEN STELLAR WINDS; X-RAY-EMISSION; DYNAMICAL SIMULATIONS; MAGNETIC-FIELDS; ROAP STARS; O-STARS; OPHIUCHI; VARIABILITY; FORS-1; MODEL;
D O I：
10.1002/asna.201713457
中图分类号：
P1 [天文学];
学科分类号：
0704 ;
摘要：
Recent XMM-Newton observations of the B2 type star Oph A indicated a periodicity of 1.205 day, which was ascribed to rotational modulation. Since variability of X-ray emission in massive stars is frequently the signature of a magnetic field, we investigated whether the presence of a magnetic field can indeed be invoked to explain the observed X-ray peculiarity. Two FORS 2 spectropolarimetric observations in different rotation phases revealed the presence of a negative (B-zall = - 419 +/- 101 G) and positive (B-zall = 538 +/- 69 G) longitudinal magnetic field, respectively. We estimate a lower limit for the dipole strength as B-d = 1.9 +/- 0.2 kG. Our calculations of the Kepler and Alfven radii imply the presence of a centrifugally supported, magnetically confined plasma around Oph A. The study of the spectral variability indicates a behavior similar to that observed in typical magnetic early-type Bp stars.
引用
收藏
页码：72 / 77
页数：6
相关论文
共 39 条
  • [1] ANGEL JRP, 1970, ASTROPHYS J, V160, pL14
  • [2] Appenzeller I., 1998, MESSENGER, V94, P1
  • [3] Babel J, 1997, ASTRON ASTROPHYS, V323, P121
  • [4] THE EFFECTIVE TEMPERATURE SCALE
    BOHMVITENSE, E
    [J]. ANNUAL REVIEW OF ASTRONOMY AND ASTROPHYSICS, 1981, 19 : 295 - 317
  • [5] Cesarsky CJ, 1996, ASTRON ASTROPHYS, V315, pL32
  • [6] Gravity and limb-darkening coefficients for the Kepler, CoRoT, Spitzer, uvby, UBVRIJHK, and Sloan photometric systems
    Claret, A.
    Bloemen, S.
    [J]. ASTRONOMY & ASTROPHYSICS, 2011, 529
  • [7] DISCOVERY OF TWO RARE RIGIDLY ROTATING MAGNETOSPHERE STARS IN THE APOGEE SURVEY
    Eikenberry, Stephen S.
    Chojnowski, S. Drew
    Wisniewski, John
    Majewski, Steven R.
    Shetrone, Matthew
    Whelan, David G.
    Bizyaev, Dmitry
    Borish, H. Jacob
    Davenport, James R. A.
    Ebelke, Garrett
    Feuillet, Diane
    Frinchaboy, Peter M.
    Garner, Alan
    Hearty, Fred
    Holtzman, Jon
    Li, Zhi-Yun
    Meszaros, Sz
    Nidever, David L.
    Schneider, Donald P.
    Skrutskie, Michael
    Wilson, John C.
    Zasowski, Gail
    [J]. ASTROPHYSICAL JOURNAL LETTERS, 2014, 784 (02)
  • [8] Grids of stellar models with rotation I. Models from 0.8 to 120 M⊙ at solar metallicity (Z=0.014)
    Ekstroem, S.
    Georgy, C.
    Eggenberger, P.
    Meynet, G.
    Mowlavi, N.
    Wyttenbach, A.
    Granada, A.
    Decressin, T.
    Hirschi, R.
    Frischknecht, U.
    Charbonnel, C.
    Maeder, A.
    [J]. ASTRONOMY & ASTROPHYSICS, 2012, 537
  • [9] Magnetic Field Generation in Stars
    Ferrario, Lilia
    Melatos, Andrew
    Zrake, Jonathan
    [J]. SPACE SCIENCE REVIEWS, 2015, 191 (1-4) : 77 - 109
  • [10] The origin of magnetism on the upper main sequence
    Ferrario, Lilia
    Pringle, J. E.
    Tout, Christopher A.
    Wickramasinghe, D. T.
    [J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2009, 400 (01) : L71 - L74
1234