Dark Kinetic Heating of Exoplanets and Brown Dwarfs

TL;DR

This paper explores how dark kinetic heating can significantly warm exoplanets and brown dwarfs due to long-range dark forces, enhancing dark matter detection prospects through infrared observations.

Contribution

It introduces the concept of dark kinetic heating in low-escape velocity objects and sets new constraints on dark sector parameters using infrared data.

Findings

Dark kinetic heating can be substantial in exoplanets and brown dwarfs.

Constraints on dark matter interactions are improved using WISE and JWST data.

Potential for detecting dark matter via heating signals in various celestial objects.

Abstract

Dark kinetic heating of neutron stars has been previously studied as a promising dark matter detection avenue. Kinetic heating occurs when dark matter is sped up to relativistic speeds in the gravitational well of high-escape velocity objects, and deposits kinetic energy after becoming captured by the object, thereby increasing its temperature. We show that dark kinetic heating can be significant even in objects with low-escape velocities, such as exoplanets and brown dwarfs, increasing the discovery potential of such searches. This can occur if there is a long-range dark force, creating a "dark escape velocity", leading to heating rates substantially larger than those expected from neutron stars. We consequently set constraints on dark sector parameters using Wide-field Infrared Survey Explorer and JWST data on Super-Jupiter WISE 0855-0714, and map out future sensitivity to the dark matter scattering cross section below $10^{-40}~{\rm cm}^2$. We compare dark kinetic heating rates of other lower escape velocity objects such as the Earth, Sun, and white dwarfs, finding complementary kinetic heating signals are possible depending on particle physics parameters.