期刊
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
卷 499, 期 2, 页码 2564-2574出版社
OXFORD UNIV PRESS
DOI: 10.1093/mnras/staa2969
关键词
stars: abundances; stars: individual: SDSS J121929.45+471522.8; planet-star interactions; white dwarfs
资金
- UK Science and Technology Facilities Council (STFC) [ST/T000406/1]
- State Research Agency (AEI) of the Spanish Ministry of Science, Innovation and Universities (MCIU)
- European Regional Development Fund (FEDER) [AYA2017-83383-P]
- European Research Council under the European Union's Horizon 2020 research and innovation programme [677706]
- UK Science and Technology Facilities Council
- Alfred P. Sloan Foundation
- U.S. Department of Energy Office of Science
- Center for High-Performance Computing at the University of Utah
- Max Planck Institute for Astronomy, Heidelberg
- Max Planck Institute for Extraterrestrial Physics, Garching
- Johns Hopkins University
- Durham University
- University of Edinburgh
- Queen's University Belfast
- Harvard-Smithsonian Center for Astrophysics
- Las Cumbres Observatory Global Telescope Network Incorporated
- National Central University of Taiwan
- Space Telescope Science Institute
- National Aeronautics and Space Administration [NNX08AR22G]
- National Science Foundation [AST-1238877, AST-1440341]
- University of Maryland
- Eotvos Lorand University (ELTE)
- LosAlamos National Laboratory
- Gordon and Betty Moore Foundation
- Caltech
- IPAC
- Weizmann Institute for Science
- Oskar Klein Center at Stockholm University
- University of Washington
- Deutsches Elektronen-Synchrotron
- Humboldt University
- Los Alamos National Laboratories
- TANGO Consortium of Taiwan
- University ofWisconsin at Milwaukee
- Lawrence Berkeley National Laboratories
- National Aeronautics and Space Administration
- STFC [ST/T000406/1, ST/P006892/1, ST/S006176/1] Funding Source: UKRI
We report the identification of SDSS J121929.45+471522.8 as the third apparently isolated magnetic (B similar or equal to 18.5 +/- 1.0MG) white dwarf exhibiting Zeeman-split Balmer emission lines. The star shows coherent variability at optical wavelengths with an amplitude of similar or equal to 0.03 mag and a period of 15.26 h, which we interpret as the spin period of the white dwarf. Modelling the spectral energy distribution and Gaia parallax, we derive a white dwarf temperature of 7500 +/- 148 K, a mass of 0.649 +/- 0.022 M-circle dot, and a cooling age of 1.5 +/- 0.1Gyr, as well as an upper limit on the temperature of a sub-stellar or giant planet companion of similar or equal to 250 K. The physical properties of this white dwarf match very closely those of the other two magnetic white dwarfs showing Balmer emission lines: GD356 and SDSS J125230.93-023417.7. We argue that, considering the growing evidence for planets and planetesimals on close orbits around white dwarfs, the unipolar inductor model provides a plausible scenario to explain the characteristics of this small class of stars. The tight clustering of the three stars in cooling age suggests a common mechanism switching the unipolar inductor on and off. Whereas Lorentz drift naturally limits the lifetime of the inductor phase, the relatively late onset of the line emission along the white dwarf cooling sequence remains unexplained.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据