Bagnulo, Stefano;
Farihi, Jay;
Landstreet, John D;
Folsom, Colin P;
(2024)
Discovery of Magnetically Guided Metal Accretion onto a Polluted White Dwarf.
Astrophysical Journal Letters
, 963
(1)
, Article L22. 10.3847/2041-8213/ad2619.
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Abstract
Dynamically active planetary systems orbit a significant fraction of white dwarf stars. These stars often exhibit surface metals accreted from debris disks, which are detected through infrared excess or transiting structures. However, the full journey of a planetesimal from star-grazing orbit to final dissolution in the host star is poorly understood. Here, we report the discovery that the cool metal-polluted star WD 0816–310 has cannibalized heavy elements from a planetary body similar in size to Vesta, and where accretion and horizontal mixing processes have clearly been controlled by the stellar magnetic field. Our observations unveil periodic and synchronized variations in metal line strength and magnetic field intensity, implying a correlation between the local surface density of metals and the magnetic field structure. Specifically, the data point to a likely persistent concentration of metals near a magnetic pole. These findings demonstrate that magnetic fields may play a fundamental role in the final stages of exoplanetary bodies that are recycled into their white dwarf hosts.
| Type: | Article |
|---|---|
| Title: | Discovery of Magnetically Guided Metal Accretion onto a Polluted White Dwarf |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.3847/2041-8213/ad2619 |
| Publisher version: | http://dx.doi.org/10.3847/2041-8213/ad2619 |
| Language: | English |
| Additional information: | Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, PLANETARY DEBRIS, AP STARS, CIRCUMSTELLAR DEBRIS, FIELD MEASUREMENTS, SOLAR-SYSTEM, TIDAL DEBRIS, X-RAY, DISCS, FORS1, CIRCULARIZATION |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10189031 |
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