We report the detection of the full orbital phase curve and occultation of the hot-Jupiter WASP-100b using TESS photometry .
The phase curve is isolated by suppressing low frequency stellar and instrumental modes using both a non-parametric harmonic notch filter ( phasma ) and semi-sector long polynomials .
This yields a phase curve signal of ( 73 \pm 9 ) ppm amplitude , preferred over a null-model by \Delta \mathrm { BIC } = 25 , indicating very strong evidence for an observed effect .
We recover the occultation event with a suite of five temporally localized tools , including Gaussian processes and cosine filtering .
This allows us to infer an occultation depth of ( 100 \pm 14 ) ppm , with an additional \pm 16 ppm systematic error from the differences between methods .
We regress a model including atmospheric reflection , emission , ellipsoidal variations and Doppler beaming to the combined phase curve and occultation data .
This allows us to infer that WASP-100b has a geometric albedo of A _ { g } = 0.16 ^ { +0.04 } _ { -0.03 } in the TESS bandpass , with a maximum dayside brightness temperature of ( 2710 \pm 100 ) K and a warm nightside temperature of ( 2380 ^ { +170 } _ { -200 } ) K. Additionally , we find evidence that WASP-100b has a high thermal redistribution efficiency , manifesting as a substantial eastward hotspot offset of ( 71 ^ { +2 } _ { -4 } ) ^ { \circ } .
These results present the first measurement of a thermal phase shift among the phase curves observed by TESS so far , and challenge the predicted efficiency of heat transport in the atmospheres of ultra-hot Jupiters .