A survey for planetary-mass brown dwarfs in the Taurus and Perseus star-forming regions. A census of young stars and brown dwarfs in IC 348 and NGC 1333.
Occurrence, mass distribution and orbital properties of super-Earths and Neptune-mass planets. The HARPS search for southern extra-solar planets XXXIV. Planet occurrence within 0.25 AU of solar-type stars from Kepler. A closely packed system of low-mass, low-density planets transiting Kepler-11. Detection of planetary transits across a Sun-like star. The statistical properties of stars and their dependence on metallicity. The stellar IMF from isothermal MHD turbulence. Haugbølle, T., Padoan, P., & Nordlund, Å. in The Initial Mass Function 50 Years Later Astrophysics and Space Science Library Vol. No large population of unbound or wide-orbit Jupiter-mass planets. New isolated planetary-mass objects and the stellar and substellar mass function of the σ Orionis cluster. Substellar Objects in Nearby Young Clusters (SONYC). KMT-201 and the nature of the free-floating planet population. A terrestrial-mass rogue planet candidate detected in the shortest-timescale microlensing event. Therefore, ejections due to dynamical instabilities in giant exoplanet systems must be frequent within the first 10 Myr of a system’s life. We estimate that ejection from planetary systems might have a contribution comparable to that of core collapse in the formation of FFPs. We found an excess of FFPs by a factor of up to seven compared with core-collapse model predictions 6, 7, 8, demonstrating that other formation mechanisms may be at work. Here we report the discovery of between 70 and 170 FFPs (depending on the assumed age) in the region encompassing Upper Scorpius and Ophiuchus, the closest young OB association to the Sun.
Several studies have identified FFPs in young stellar clusters 3, 4 and the Galactic field 5 but their samples are small or heterogeneous in age and origin. However, the ephemeral nature of microlensing events prevents any follow-up observations and individual characterization. So far, most FFPs have been discovered using indirect methods microlensing surveys have proved particularly successful to detect these objects down to a few Earth masses 1, 2. The nature and origin of free-floating planets (FFPs) are still largely unconstrained because of a lack of large homogeneous samples to enable a statistical analysis of their properties.