Enhanced thermal radiation from a tidally heated exomoon with a single hot spot

Abstract

An exomoon on a non perfectly circular orbit experiences tidal heating that is capable to significantly contribute to the thermal brightness of the moon. Here we argue that the thermal heat is unevenly distributed on the moon's surface, the emission of the tidal heat is limited to a few hot spots on the surface. A well-known example is the tidally heated Io. Due to their significantly increased temperature, the hot spots enhance the energy emission in thermal wavelengths. We made simulations using Monte-Carlo method to examine this contribution, and to predict about the possible detectability of such a spotted exomoon. We found that in the case of large, Earth sized companions to jupiters around red dwarf stars exhibit a thermal flux that enables the direct detection of the moon, due to its photometric signal that can exceed $\approx$100 ppm in the most favourable configurations.

Accepted by MNRAS, 16 pages

References in corpus (11)

• Transit timing effects due to an exomoon
• The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
• Determination of the size, mass, and density of "exomoons" from photometric transit timing variations
• Detecting companions to extrasolar planets using mutual events
• The Luminosities of the Coldest Brown Dwarfs
• An alternative interpretation of the exomoon candidate signal in the combined Kepler and Hubble data of Kepler-1625
• Viscoelastic Models of Tidally Heated Exomoons
• Io's Volcanic Activity from Time Domain Adaptive Optics Observations: 2013-2018
• Low Albedo Surfaces of Lava Worlds
• On The Feasibility of Exomoon Detection Via Exoplanet Phase Curve Spectral Contrast
• The Y dwarf population with HST: unlocking the secrets of our coolest neighbours -- I. Overview & First astrometric results