A Giant Planet Candidate Transiting a White Dwarf
Creators: name: Vanderburg, Andrew
name: Rappaport, Saul A.
name: Xu, Siyi
name: Crossfield, Ian
name: Becker, Juliette C.
name: Gary, Bruce
name: Murgas, Felipe
name: Blouin, Simon
name: Kaye, Thomas G.
name: Palle, Enric
name: Melis, Carl
name: Morris, Brett
name: Kreidberg, Laura
name: Gorjian, Varoujan
name: Morley, Caroline V.
name: Mann, Andrew W.
name: Parviainen, Hannu
name: Pearce, Logan A.
name: Newton, Elisabeth R.
name: Carrillo, Andreia
name: Zuckerman, Ben
name: Nelson, Lorne
name: Zeimann, Greg
name: Brown, Warren R.
name: Tronsgaard, René
name: Klein, Beth
name: Ricker, George R.
name: Vanderspek, Roland K.
name: Latham, David W.
name: Seager, Sara
name: Winn, Joshua N.
name: Jenkins, Jon M.
name: Adams, Fred C.
name: Benneke, Björn
name: Berardo, David
name: Buchhave, Lars A.
name: Caldwell, Douglas A.
name: Christiansen, Jessie L.
name: Collins, Karen A.
name: Colón, Knicole D.
name: Daylan, Tansu
name: Doty, John
name: Doyle, Alexandra E.
name: Dragomir, Diana
name: Dressing, Courtney
name: Dufour, Patrick
name: Fukui, Akihiko
name: Glidden, Ana
name: Guerrero, Natalia M.
name: Guo, Xueying
name: Heng, Kevin
name: Henriksen, Andreea I.
name: Huang, Chelsea X.
name: Kaltenegger, Lisa
name: Kane, Stephen R.
name: Lewis, John A.
name: Lissauer, Jack J.
name: Morales, Farisa
name: Narita, Norio
name: Pepper, Joshua
name: Rose, Mark E.
name: Smith, Jeffrey C.
name: Stassun, Keivan G.
name: Yu, Liang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Astronomers have discovered thousands of planets outside the solar system, most of which orbit stars that will eventually evolve into red giants and then into white dwarfs. During the red giant phase, any close-orbiting planets will be engulfed by the star, but more distant planets can survive this phase and remain in orbit around the white dwarf. Some white dwarfs show evidence for rocky material floating in their atmospheres, in warm debris disks, or orbiting very closely, which has been interpreted as the debris of rocky planets that were scattered inward and tidally disrupted. Recently, the discovery of a gaseous debris disk with a composition similar to ice giant planets demonstrated that massive planets might also find their way into tight orbits around white dwarfs, but it is unclear whether the planets can survive the journey. So far, the detection of intact planets in close orbits around white dwarfs has remained elusive. Here, we report the discovery of a giant planet candidate transiting the white dwarf WD 1856+534 (TIC 267574918) every 1.4 days. The planet candidate is roughly the same size as Jupiter and is no more than 14 times as massive (with 95% confidence). Other cases of white dwarfs with close brown dwarf or stellar companions are explained as the consequence of common-envelope evolution, wherein the original orbit is enveloped during the red-giant phase and shrinks due to friction. In this case, though, the low mass and relatively long orbital period of the planet candidate make common-envelope evolution less likely. Instead, the WD 1856+534 system seems to demonstrate that giant planets can be scattered into tight orbits without being tidally disrupted, and motivates searches for smaller transiting planets around white dwarfs.
description: 50 pages, 12 figures, 2 tables. Published in Nature on Sept. 17, 2020. The final authenticated version is available online at: https://www.nature.com/articles/s41586-020-2713-y