English

Gravity-Darkened Seasons: Insolation Around Rapid Rotators

Earth and Planetary Astrophysics 2016-12-07 v1

Abstract

I model the effect of rapid stellar rotation on a planet's insolation. Fast-rotating stars have induced pole-to-equator temperature gradients (known as gravity-darkening) of up to several thousand Kelvin that affect the star's luminosity and peak emission wavelength as a function of latitude. When orbiting such a star, a planet's annual insolation can strongly vary depending on its orbit inclination. Specifically, inclined orbits result in temporary exposure to the star's hotter poles. I find that gravity-darkening can drive changes in a planet's equilibrium temperature of up to 15%\sim15\% due to increased irradiance near the stellar poles. This effect can also vary a planet's exposure to UV radiation by up to 80%\sim80\% throughout its orbit as it is exposed to an irradiance spectrum corresponding to different stellar effective temperatures over time.

Keywords

Cite

@article{arxiv.1609.07106,
  title  = {Gravity-Darkened Seasons: Insolation Around Rapid Rotators},
  author = {John P. Ahlers},
  journal= {arXiv preprint arXiv:1609.07106},
  year   = {2016}
}

Comments

8 pages, 6 figures, accepted for publication in ApJ

R2 v1 2026-06-22T15:58:22.179Z