TY - JOUR
T1 - K2-161b
T2 - A low-density super-neptune on an eccentric orbit
AU - Brahm, R.
AU - Espinoza, N.
AU - Rabus, M.
AU - Jordán, A.
AU - Díaz, M. R.
AU - Rojas, F.
AU - Vučković, M.
AU - Zapata, A.
AU - Cortés, C.
AU - Drass, H.
AU - Jenkins, J. S.
AU - Lachaume, R.
AU - Pantoja, B.
AU - Sarkis, P.
AU - Soto, M. G.
AU - Vasquez, S.
AU - Henning, Th
AU - Jones, M. I.
N1 - Publisher Copyright:
© 2018 The Author(s).
PY - 2019/2/21
Y1 - 2019/2/21
N2 - We report the discovery of K2-161b, which was first identified as a planetary candidate from Kepler K2 photometry of Campaign 14, and whose planetary nature and orbital parameters were then confirmed with precision radial velocities. K2-161b is half as massive as Saturn (MP = 0.179 ± 0.021 MJ), and has a radius of RP = 0.840 ± 0.011 RJ, which translates into a bulk density of ρP = 0.37 ± 0.05 g cm-3. K2-161b transits its slightly evolved G-type host star (M∗ = 1.105 ± 0.019 M⊙, R∗ = 1.669 ± 0.022 R⊙) every 11.633 64 ± 0.000 10 d and presents a significantly eccentric orbit (e = 0.420 ± 0.034). We estimate a relatively short circularization time-scale of 1.8 Gyr for the planet, but given the advanced age of the system we expect the planet to be engulfed by its evolving host star in ∼1 Gyr before the orbit circularizes. The low density of the planet coupled to the brightness of the host star (J = 9.4) makes this system one of the best candidates known to date in the super-Neptune regime for atmospheric characterization via transmission spectroscopy, and to further study the transition region between ice and gas giant planets.
AB - We report the discovery of K2-161b, which was first identified as a planetary candidate from Kepler K2 photometry of Campaign 14, and whose planetary nature and orbital parameters were then confirmed with precision radial velocities. K2-161b is half as massive as Saturn (MP = 0.179 ± 0.021 MJ), and has a radius of RP = 0.840 ± 0.011 RJ, which translates into a bulk density of ρP = 0.37 ± 0.05 g cm-3. K2-161b transits its slightly evolved G-type host star (M∗ = 1.105 ± 0.019 M⊙, R∗ = 1.669 ± 0.022 R⊙) every 11.633 64 ± 0.000 10 d and presents a significantly eccentric orbit (e = 0.420 ± 0.034). We estimate a relatively short circularization time-scale of 1.8 Gyr for the planet, but given the advanced age of the system we expect the planet to be engulfed by its evolving host star in ∼1 Gyr before the orbit circularizes. The low density of the planet coupled to the brightness of the host star (J = 9.4) makes this system one of the best candidates known to date in the super-Neptune regime for atmospheric characterization via transmission spectroscopy, and to further study the transition region between ice and gas giant planets.
KW - Planets and satellites: fundamental parameters
KW - Stars: fundamental parameters
KW - Stars: individual: K2-161
KW - Techniques: photometric
KW - Techniques: radial velocities
UR - http://www.scopus.com/inward/record.url?scp=85066980377&partnerID=8YFLogxK
U2 - 10.1093/mnras/sty3230
DO - 10.1093/mnras/sty3230
M3 - Article
AN - SCOPUS:85066980377
SN - 0035-8711
VL - 483
SP - 1970
EP - 1979
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 2
ER -