Astronomy & Astrophysics manuscript no. ms c ESO 2019 April 12, 2019 Survival rates of planets in open clusters: The Pleiades, Hyades, and Praesepe clusters M. S. Fujii1 and Y. Hori2,3 1 Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 1130033, Japan e-mail:
[email protected] 2 Astrobiology Center, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan 3 National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 1818588, Japan e-mail:
[email protected] Received November xx, 2018; accepted xxxx xx, 2018 ABSTRACT Context. In clustered environments, stellar encounters can liberate planets from their host stars via close encounters. Although the detection probability of planets suggests that the planet population in open clusters resembles that in the field, only a few dozen planet-hosting stars have been discovered in open clusters. Aims. We explore the survival rates of planets against stellar encounters in open clusters similar to the Pleiades, Hyades, and Praesepe and embedded clusters. Methods. We performed a series of N-body simulations of high-density and low-density open clusters, open clusters that grow via mergers of subclusters, and embedded clusters. We semi-analytically calculated the survival rate of planets in star clusters up to ∼1 Gyr using relative velocities, masses, and impact parameters of intruding stars. Results. Less than 1.5 % of close-in planets within 1 AU and at most 7 % of planets with 1–10 AU are ejected by stellar encounters in clustered environments after the dynamical evolution of star clusters.