دورية أكاديمية
An irradiated brown-dwarf companion to an accreting white dwarf.
| العنوان: | An irradiated brown-dwarf companion to an accreting white dwarf. |
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| المؤلفون: | Santisteban JV; Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK., Knigge C; Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK., Littlefair SP; Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK., Breton RP; Department of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ, UK.; Jodrell Bank Centre for Astrophysics, School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK., Dhillon VS; Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK.; Instituto de Astrofísica de Canarias, E-38205 La Laguna, Santa Cruz de Tenerife, Spain., Gänsicke BT; Department of Physics, University of Warwick, Coventry CV4 7AL, UK., Marsh TR; Department of Physics, University of Warwick, Coventry CV4 7AL, UK., Pretorius ML; Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK., Southworth J; Astrophysics Group, Keele University, Newcastle ST5 5BG, UK., Hauschildt PH; Hamburger Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany. |
| المصدر: | Nature [Nature] 2016 May 19; Vol. 533 (7603), pp. 366-8. |
| نوع المنشور: | Journal Article; Research Support, Non-U.S. Gov't |
| اللغة: | English |
| بيانات الدورية: | Publisher: Nature Publishing Group Country of Publication: England NLM ID: 0410462 Publication Model: Print Cited Medium: Internet ISSN: 1476-4687 (Electronic) Linking ISSN: 00280836 NLM ISO Abbreviation: Nature Subsets: PubMed not MEDLINE |
| أسماء مطبوعة: | Publication: Basingstoke : Nature Publishing Group Original Publication: London, Macmillan Journals ltd. |
| مستخلص: | Interacting compact binary systems provide a natural laboratory in which to study irradiated substellar objects. As the mass-losing secondary (donor) in these systems makes a transition from the stellar to the substellar regime, it is also irradiated by the primary (compact accretor). The internal and external energy fluxes are both expected to be comparable in these objects, providing access to an unexplored irradiation regime. The atmospheric properties of donors are largely unknown, but could be modified by the irradiation. To constrain models of donor atmospheres, it is necessary to obtain accurate observational estimates of their physical properties (masses, radii, temperatures and albedos). Here we report the spectroscopic detection and characterization of an irradiated substellar donor in an accreting white-dwarf binary system. Our near-infrared observations allow us to determine a model-independent mass estimate for the donor of 0.055 ± 0.008 solar masses and an average spectral type of L1 ± 1, supporting both theoretical predictions and model-dependent observational constraints that suggest that the donor is a brown dwarf. Our time-resolved data also allow us to estimate the average irradiation-induced temperature difference between the dayside and nightside of the substellar donor (57 kelvin) and the maximum difference between the hottest and coolest parts of its surface (200 kelvin). The observations are well described by a simple geometric reprocessing model with a bolometric (Bond) albedo of less than 0.54 at the 2σ confidence level, consistent with high reprocessing efficiency, but poor lateral heat redistribution in the atmosphere of the brown-dwarf donor. These results add to our knowledge of binary evolution, in that the donor has survived the transition from the stellar to the substellar regime, and of substellar atmospheres, in that we have been able to test a regime in which the irradiation and the internal energy of a brown dwarf are comparable. |
| التعليقات: | Comment in: Nature. 2016 May 19;533(7603):330-1. (PMID: 27193676) |
| References: | Science. 2006 Dec 8;314(5805):1578-80. (PMID: 17158322) Science. 2014 Nov 14;346(6211):838-41. (PMID: 25301972) |
| تواريخ الأحداث: | Date Created: 20160520 Date Completed: 20160614 Latest Revision: 20181113 |
| رمز التحديث: | 20240628 |
| DOI: | 10.1038/nature17952 |
| PMID: | 27193683 |
| قاعدة البيانات: | MEDLINE |
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Full Text Finder | تدمد: | 1476-4687 |
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| DOI: | 10.1038/nature17952 |