Tootfinder

Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase
Andr\'e Izidoro, Sean N. Raymond, Nathan A. Kaib, Alessandro Morbidelli, Andrea Isella
https://arxiv.org/abs/2505.24093

Very-wide-orbit planets from dynamical instabilities during the stellar birth cluster phase
Gas giant planets have been detected on eccentric orbits several hundreds of astronomical units in size around other stars. It has been proposed that even the Sun hosts a wide-orbit planet of 5-10 Earth masses, often called Planet Nine, which influences the dynamics of distant Trans-Neptunian objects. However, the formation mechanism of such planets remains uncertain. Here we use numerical simulations to show that very wide-orbit planets are a natural byproduct of dynamical instabilities that o…

The James Webb Space Telescope NIRSpec-PRISM Transmission Spectrum of the Super-Puff, Kepler-51d
Jessica E. Libby-Roberts, Aaron Bello-Arufe, Zachory K. Berta-Thompson, Caleb I. Ca\~nas, Yayaati Chachan, Renyu Hu, Yui Kawashima, Catriona Murray, Kazumasa Ohno, Armen Tokadjian, Suvrath Mahadevan, Kento Masuda, Leslie Hebb, Caroline Morley, Guangwei Fu, Peter Gao, Kevin B. Stevenson

The James Webb Space Telescope NIRSpec-PRISM Transmission Spectrum of the Super-Puff, Kepler-51d
Kepler-51 is a 500 Myr G dwarf hosting three "super-puffs" and one low-mass non-transiting planet. Kepler-51d, the coolest (T_eq ~ 350 K) transiting planet in this system, is also one of the lowest density super-puffs known to date (rho_p = 0.038 +/- 0.009 g/cm^3). With a planetary mass of Mp = 5.6 +/- 1.2 Earth masses and a radius of Rp = 9.32 +/- 0.18 Earth radii, the observed properties of this planet are not readily explained by most planet formation theories. Hypotheses explaining Kepler-5…