K2-287 b: An Eccentric Warm Saturn Transiting a G-dwarf

Journal Article · Fri Mar 01 04:00:00 EST 2019 · The Astronomical Journal (Online)

DOI:https://doi.org/10.3847/1538-3881/AAFA79· OSTI ID:22897323

Jordán, Andrés; Brahm, Rafael; Rojas, Felipe ^[1]; Espinoza, Néstor; Henning, Thomas; Sarkis, Paula ^[2]; Cortés, Cristián ^[3]; Díaz, Matías; Jenkins, James S. ^[4]; Drass, Holger ^[5]; Jones, Matías I. ^[6]; Rabus, Markus; Zapata, Abner ^[7]; Vučković, Maja ^[8]; others, and

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1. Instituto de Astrofísica, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago (Chile)
2. Max-Planck-Institut für Astronomie, Königstuhl 17, Heidelberg D-69117 (Germany)
3. Departamento de Física, Facultad de Ciencias Básicas, Universidad Metropolitana de la Educación, Av. José Pedro Alessandri 774, 7760197, Nuñoa, Santiago (Chile)
4. Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago (Chile)
5. Millennium Institute for Astrophysics (Chile)
6. European Southern Observatory, Casilla 19001, Santiago (Chile)
7. Center of Astro-Engineering UC, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile)
8. Instituto de Física y Astronomía, Universidad de Vaparaíso, Casilla 5030, Valparaíso (Chile)

We report the discovery of K2-287b, a Saturn mass planet orbiting a G-dwarf with a period of P ≈ 15 days. First uncovered as a candidate using K2 campaign 15 data, follow-up photometry and spectroscopy were used to determine a mass M{sub P}=0.317±0.026 M{sub J}, radius R{sub P}=0.833±0.013 R{sub J}, period P=14.893291±0.000025 days, and eccentricity e=0.476±0.026. The host star is a metal-rich V = 11.410 ± 0.129 mag G-dwarf for which we estimate a mass M{sub ⋆}=1.056{sub −0.021}{sup +0.022} M{sub ⊙}, radius R{sub ⋆}=1.070±0.010 R{sub ⊙}, metallicity [Fe/H] = 0.20 ±0.05, and T{sub eff}=5673±75 K. This warm eccentric planet with a time-averaged equilibrium temperature of T{sub eq}≈800 K adds to the small sample of giant planets orbiting nearby stars whose structure is not expected to be affected by stellar irradiation. Follow-up studies on the K2-287 system could help constrain theories of planet migration in close-in orbits.

• OSTI ID: 22897323
• Journal Information: The Astronomical Journal (Online), Journal Name: The Astronomical Journal (Online) Journal Issue: 3 Vol. 157; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DETECTION
DWARF STARS
MASS
METALLICITY
MIGRATION
ORBITS
PHOTOMETRY
PLANETS
SATELLITES
SPECTROSCOPY