Search for Outer Massive Bodies around Transiting Planetary Systems: Candidates of Faint Stellar Companions around HAT-P-7

• Published in: Publications of the Astronomical Society of Japan 2010-06, Vol.62 (3), p.779-786
• Main Authors: Narita, Norio, Kudo, Tomoyuki, Bergfors, Carolina, Nagasawa, Makiko, Thalmann, Christian, Sato, Bun’ei, Suzuki, Ryuji, Kandori, Ryo, Janson, Markus, Goto, Miwa, Brandner, Wolfgang, Ida, Shigeru, Abe, Lyu, Carson, Joseph, Egner, Sebastian E., Feldt, Markus, Golota, Taras, Guyon, Olivier, Hashimoto, Jun, Hayano, Yutaka, Hayashi, Masahiko, Hayashi, Saeko S., Henning, Thomas, Hodapp, Klaus W., Ishii, Miki, Knapp, Gillian R., Kusakabe, Nobuhiko, Kuzuhara, Masayuki, Matsuo, Taro, McElwain, Michael W., Miyama, Shoken M., Morino, Jun-Ichi, Moro-Martin, Amaya, Nishimura, Tetsuo, Pyo, Tae-Soo, Serabyn, Eugene, Suenaga, Takuya, Suto, Hiroshi, Takahashi, Yasuhiro Haruhi, Takami, Michihiro, Takato, Naruhisa, Terada, Hiroshi, Tomono, Daigo, Turner, Edwin L., Watanabe, Makoto, Yamada, Toru, Takami, Hideki, Usuda, Tomonori, Tamura, Motohide
• Format: Article
• Language: English
• ISSN: 0004-6264; 2053-051X
• DOI: 10.1093/pasj/62.3.779

We present results of direct imaging observations for HAT-P-7 taken with the Subaru HiCIAO and the Calar Alto AstraLux. Since the close-in transiting planet HAT-P-7b was reported to have a highly tilted orbit, massive bodies such as giant planets, brown dwarfs, and a binary star are expected to exist in the outer region of this system. We show that there are indeed two candidates for distant faint stellar companions around HAT-P-7. We discuss how such companions can play a role on the orbital evolution of HAT-P-7b. We conclude that since there is a third body in the system, as reported by Winn et al. (2009, ApJ, 763, L99), Kozai migration is less likely, while planet–planet scattering is possible.