2023-06-12 バーミンガム大学
◆この発見は、BEBOP（Binaries Escorted By Orbiting Planets）というプロジェクトによって収集されたデータをもとに行われました。この新たに発見された惑星はBEBOP-1cと呼ばれています。これまでに知られている二重星系はわずか12個であり、この系統で複数の惑星を持つのは二例目です。
＜関連情報＞
- https://www.birmingham.ac.uk/news/2023/a-new-tatooine-like-multi-planetary-system-identified
- https://www.nature.com/articles/s41550-023-01948-4
TOI-1338/BEBOP-1循環系における第2惑星の放射速度発見 Radial-velocity discovery of a second planet in the TOI-1338/BEBOP-1 circumbinary system
Matthew R. Standing,Lalitha Sairam,David V. Martin,Amaury H. M. J. Triaud,Alexandre C. M. Correia,Gavin A. L. Coleman,Thomas A. Baycroft,Vedad Kunovac,Isabelle Boisse,Andrew Collier Cameron,Georgina Dransfield,João P. Faria,Michaël Gillon,Nathan C. Hara,Coel Hellier,Jonathan Howard,Ellie Lane,Rosemary Mardling,Pierre F. L. Maxted,Nicola J. Miller,Richard P. Nelson,Jerome A. Orosz,Franscesco Pepe,Alexandre Santerne,Daniel Sebastian,Stéphane Udry & William F. Welsh
Nature Astronomy Published:12 June 2023
DOI:https://doi.org/10.1038/s41550-023-01948-4
Abstract
Circumbinary planets, those that orbit around both stars of a central binary star system, challenge our understanding of planet formation. With only 12 binary systems known to host circumbinary planets, identifying more of these planets, along with their physical properties, could help to discern some of the physical processes that govern planet formation. Here we analyse radial-velocity data obtained by the HARPS and ESPRESSO spectrographs and report the detection of BEBOP-1 c, a gas giant planet with a mass of 65.2 ± 11.8 Earth masses (M⊕) orbiting around both stars of an eclipsing binary star system with a period of 215.5 ± 3.3 days. The system TOI-1338, hereafter referred to as BEBOP-1, which also hosts the smaller and inner transiting planet TOI-1338 b, is only the second confirmed multiplanetary circumbinary system. We do not detect TOI-1338 b with radial-velocity data alone, and we can place an upper limit on its mass of 21.8 M⊕ with 99% confidence. TOI-1338 b is amenable to atmospheric characterization using JWST, so the BEBOP-1 system has the potential to act as a benchmark for circumbinary exo-atmospheric studies.
