A super-Earth orbiting near the inner edge of the habitable zone around the M4.5 dwarf Ross 508

Harakawa, Hiroki; Takarada, Takuya; Kasagi, Yui; Hirano, Teruyuki; Kotani, Takayuki; Kuzuhara, Masayuki; Omiya, Masashi; Kawahara, Hajime; Fukui, Akihiko; Hori, Yasunori; Ishikawa, Hiroyuki Tako; Ogihara, Masahiro; Livingston, John; Brandt, Timothy D.; Currie, Thayne; Aoki, Wako; Beichman, Charles A.; Henning, Thomas; Hodapp, Klaus; Ishizuka, Masato; Izumiura, Hideyuki; Jacobson, Shane; Janson, Markus; Kambe, Eiji; Kodama, Takanori; Kokubo, Eiichiro; Konishi, Mihoko; Krishnamurthy, Vigneshwaran; Kudo, Tomoyuki; Kurokawa, Takashi; Kusakabe, Nobuhiko; Kwon, Jungmi; Matsumoto, Yuji; McElwain, Michael W.; Mitsui, Koyu; Nakagawa, Takao; Narita, Norio; Nishikawa, Jun; Nugroho, Stevanus K.; Serabyn, Eugene; Serizawa, Takuma; Takahashi, Aoi; Ueda, Akitoshi; Uyama, Taichi; Vievard, Sébastien; Wang, Ji; Wisniewski, John; Tamura, Motohide; Sato, Bun'ei
Bibliographical reference

Publications of the Astronomical Society of Japan

Advertised on:
8
2022
Number of authors
49
IAC number of authors
1
Citations
12
Refereed citations
11
Description
We report the near-infrared radial velocity (RV) discovery of a super-Earth planet on a 10.77 d orbit around the M4.5 dwarf Ross 508 (Jmag = 9.1). Using precision RVs from the Subaru Telescope IRD (InfraRed Doppler) instrument, we derive a semi-amplitude of $3.92^{+0.60}_{-0.58}\:\mbox{m}\:{\mbox{s}^{-1}}$, corresponding to a planet with a minimum mass $m \sin i = 4.00^{+0.53}_{-0.55}\, M_{\oplus }$. We find no evidence of significant signals at the detected period in spectroscopic stellar activity indicators or MEarth photometry. The planet, Ross 508 b, has a semi-major axis of $0.05366^{+0.00056}_{-0.00049}\:$au. This gives an orbit-averaged insolation of ≍1.4 times the Earth's value, placing Ross 508 b near the inner edge of its star's habitable zone. We have explored the possibility that the planet has a high eccentricity and its host is accompanied by an additional unconfirmed companion on a wide orbit. Our discovery demonstrates that the near-infrared RV search can play a crucial role in finding a low-mass planet around cool M dwarfs like Ross 508.
Related projects
Projects' name image
Exoplanets and Astrobiology
The search for life in the universe has been driven by recent discoveries of planets around other stars (known as exoplanets), becoming one of the most active fields in modern astrophysics. The growing number of new exoplanets discovered in recent years and the recent advance on the study of their atmospheres are not only providing new valuable
Enric
Pallé Bago