TY - JOUR
T1 - The HARPS search for southern extra-solar planets. XLIII. A compact system of four super-Earth planets orbiting HD 215152
AU - Delisle, J.-B.
AU - Ségransan, D.
AU - Dumusque, X.
AU - Diaz, R. F.
AU - Bouchy, F.
AU - Lovis, C.
AU - Pepe, F.
AU - Udry, S.
AU - Alonso, R.
AU - Benz, W.
AU - Coffinet, A.
AU - Collier Cameron, A.
AU - Deleuil, M.
AU - Figueira, P.
AU - Gillon, M.
AU - Lo Curto, G.
AU - Mayor, M.
AU - Mordasini, C.
AU - Motalebi, F.
AU - Moutou, C.
AU - Pollacco, D.
AU - Pompei, E.
AU - Queloz, D.
AU - Santos, N. C.
AU - Wyttenbach, A.
PY - 2018/6
Y1 - 2018/6
N2 - We report the discovery of four super-Earth planets around HD 215152, with orbital periods of 5.76, 7.28, 10.86, and 25.2 d, and minimum masses of 1.8, 1.7, 2.8, and 2.9 M⊕ respectively. This discovery is based on 373 high-quality radial velocity measurements taken by HARPS over 13 years. Given the low masses of the planets, the signal-to-noise ratio is not sufficient to constrain the planet eccentricities. However, a preliminary dynamical analysis suggests that eccentricities should be typically lower than about 0.03 for the system to remain stable. With two pairs of planets with a period ratio lower than 1.5, with short orbital periods, low masses, and low eccentricities, HD 215152 is similar to the very compact multi-planet systems found by Kepler, which is very rare in radial-velocity surveys. This discovery proves that these systems can be reached with the radial-velocity technique, but characterizing them requires a huge amount of observations.
AB - We report the discovery of four super-Earth planets around HD 215152, with orbital periods of 5.76, 7.28, 10.86, and 25.2 d, and minimum masses of 1.8, 1.7, 2.8, and 2.9 M⊕ respectively. This discovery is based on 373 high-quality radial velocity measurements taken by HARPS over 13 years. Given the low masses of the planets, the signal-to-noise ratio is not sufficient to constrain the planet eccentricities. However, a preliminary dynamical analysis suggests that eccentricities should be typically lower than about 0.03 for the system to remain stable. With two pairs of planets with a period ratio lower than 1.5, with short orbital periods, low masses, and low eccentricities, HD 215152 is similar to the very compact multi-planet systems found by Kepler, which is very rare in radial-velocity surveys. This discovery proves that these systems can be reached with the radial-velocity technique, but characterizing them requires a huge amount of observations.
KW - Planets and satellites:general
KW - Planets and satellites: detection
KW - Planets and satellites: dynamical evolution and stability
U2 - 10.1051/0004-6361/201732529
DO - 10.1051/0004-6361/201732529
M3 - Article
SN - 0004-6361
VL - 614
JO - Astronomy & Astrophysics
JF - Astronomy & Astrophysics
M1 - A133
ER -