The large day–night temperature contrast of WASP-43b \citep 2014Sci…346..838S,2017AJ….153…68S has so far eluded explanation \citep [ e.g. , ] [ ] 2015ApJ…801…86K .
We revisit the energy budget of this planet by considering the impact of reflected light on dayside measurements , and the physicality of implied nightside temperatures .
Previous analyses of the infrared eclipses of WASP-43b have assumed reflected light from the planet is negligible and can be ignored .
We develop a phenomenological eclipse model including reflected light and thermal emission and use it to fit published Hubble and Spitzer eclipse data .
We infer a near-infrared geometric albedo of 24 \pm 1 % and a cooler dayside temperature of 1483 \pm 10 ~ { } K. Additionally , we perform lightcurve inversion on the three published orbital phase curves of WASP-43b and find that each suggests unphysical , negative flux on the nightside .
By requiring non-negative brightnesses at all longitudes , we correct the unphysical parts of the maps and obtain a much hotter nightside effective temperature of 1076 \pm 11 ~ { } K. The cooler dayside and hotter nightside suggests a heat recirculation efficiency of 51 % for WASP-43b , essentially the same as for HD 209458b , another hot Jupiter with nearly the same temperature .
Our analysis therefore reaffirms the trend that planets with lower irradiation temperatures have more efficient day-night heat transport .
Moreover , we note that 1 ) reflected light may be significant for many near-IR eclipse measurements of hot Jupiters , and 2 ) phase curves should be fit with physically possible longitudinal brightness profiles — it is insufficient to only require that the disk-integrated lightcurve be non-negative .