THE K2-ESPRINT PROJECT IV. A HOT JUPITER IN A PROGRADE ORBIT WITH A POSSIBLE STELLAR COMPANION

We report on the detection and early characterization of a hot Jupiter in a three day orbit around K2-34 (EPIC 212110888), a metal-rich F-type star located in the K2 Cycle 5 field. Our follow-up campaign involves precise radial velocity (RV) measurements and high-contrast imaging using multiple faci...

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Bibliographic Details
Main Authors: Hirano, Teruyuki, Nowak, Grzegorz, Kuzuhara, Masayuki, Palle, Enric, Dai, Fei, Van Eylen, Vincent, Takeda, Yoichi, Brandt, Timothy D., Narita, Norio, Velasco, Sergio, Arranz, Jorge Prieto, Sanchis-Ojeda, Roberto, Kudo, Tomoyuki, Kusakabe, Nobuhiko, Fukui, Akihiko, Sato, Bun’ei, Albrecht, Simon, Ribas, Ignasi, Ryu, Tsuguru, Tamura, Motohide, Yu, Liang, Winn, Joshua Nathan
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Published: American Astronomical Society 2018
Online Access:http://hdl.handle.net/1721.1/114499
https://orcid.org/0000-0003-1667-5427
https://orcid.org/0000-0002-4265-047X
Description
Summary:We report on the detection and early characterization of a hot Jupiter in a three day orbit around K2-34 (EPIC 212110888), a metal-rich F-type star located in the K2 Cycle 5 field. Our follow-up campaign involves precise radial velocity (RV) measurements and high-contrast imaging using multiple facilities. The absence of a bright nearby source in our high-contrast data suggests that the transit-like signals are not due to light variations from such a companion star. Our intensive RV measurements show that K2-34b (EPIC 212110888b) has a mass of 1.773 ± 0.086M[subscript J], confirming its status as a planet. We also detect the Rossiter–McLaughlin effect for K2-34b and show that the system has a good spin–orbit alignment (λ = -1[superscript +10][subscript -9] degrees). High-contrast images obtained by the HiCIAO camera on the Subaru 8.2 m telescope reveal a faint companion candidate (CC) (Δm[subscript H] = 6.19 ± 0.11 mag) at a separation of 0.'' 36. Follow-up observations are needed to confirm that the CC is physically associated with K2-34. K2-34b appears to be an example of a typical "hot Jupiter," albeit one which can be precisely characterized using a combination of K2 photometry and ground-based follow-up. Key words: planets and satellites: detection – stars: individual (EPIC 212110888, K2-34) techniques: photometric – techniques: radial velocities – techniques: spectroscopic