Two substellar survivor candidates: one found and one missing
| العنوان: | Two substellar survivor candidates: one found and one missing |
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| المؤلفون: | N Walters, J Farihi, T R Marsh, E Breedt, P W Cauley, T von Hippel, J J Hermes |
| المصدر: | Monthly Notices of the Royal Astronomical Society. 519:1381-1395 |
| بيانات النشر: | Oxford University Press (OUP), 2022. |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics |
| الوصف: | This study presents observations of two possible substellar survivors of post-main sequence engulfment, currently orbiting white dwarf stars. Infrared and optical spectroscopy of GD 1400 reveal a 9.98 h orbital period, where the benchmark brown dwarf has $M_2=68\pm8$ M$_{\rm Jup}$, $T_{\rm eff}\approx2100$ K, and a cooling age under 1 Gyr. A substellar mass in the lower range of allowed values is favoured by the gravitational redshift of the primary. Synthetic brown dwarf spectra are able to reproduce the observed CO bands, but lines below the bandhead are notably overpredicted. The known infrared excess towards PG 0010+281 is consistent with a substellar companion, yet no radial velocity or photometric variability is found despite extensive searches. Three independent stellar mass determinations all suggest enhanced mass loss associated with binary evolution, where the youngest total age for an isolated star is $7.5\pm2.5$ Gyr. A possible solution to this conundrum is the cannibalization of one or more giant planets, which enhanced mass loss post-main sequence, but were ultimately destroyed. PG 0010+281 is likely orbited by a debris disk that is comfortably exterior to the Roche limit, adding to the growing number of non-canonical disks orbiting white dwarfs. At present, only L-type (brown) dwarfs are known to survive direct engulfment during the post-main sequence, whereas T- and Y-type substellar companions persist at wide separations. These demographics indicate that roughly 50 M$_{\rm Jup}$ is required to robustly avoid post-main sequence annihilation, suggesting all closely-orbiting giant planets are consumed, which may contribute to mass loss and magnetic field generation in white dwarfs and their immediate progenitors. Comment: 15 pages, 8 figures, 3 tables. Accepted to MNRAS, dedicated to the memory of Tom Marsh |
| تدمد: | 1365-2966 0035-8711 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::1b30d48a61215198b0689aac24be39bb https://doi.org/10.1093/mnras/stac3603 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....1b30d48a61215198b0689aac24be39bb |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13652966 00358711 |
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