March 25, 2021 updates Posted on March 25, 2021 by Doug Loss The ‘Oumuamua Encounter: How Modern Cosmology Handled Its First Black Swan https://www.mdpi.com/2073-8994/13/3/510 Close encounters with the Death Star: Interactions between collapsed bodies and the Solar system https://arxiv.org/abs/2103.12745 Two Bright M Dwarfs Hosting Ultra-Short-Period Super-Earths with Earth-like Compositions https://arxiv.org/abs/2103.12760 GRIT: a package for structure-preserving simulations of gravitationally interacting rigid-bodies https://arxiv.org/abs/2103.12767 TOI-1634 b: an Ultra-Short Period Keystone Planet Sitting Inside the M Dwarf Radius Valley https://arxiv.org/abs/2103.12790 A Spectral Survey of WASP-19b with ESPRESSO https://arxiv.org/abs/2103.12858 Biases in orbit fitting of directly-imaged exoplanets with small orbital coverage https://arxiv.org/abs/2103.12877 How does the mass and activity history of the host star affect the population of low-mass planets? https://arxiv.org/abs/2103.13117