Phase curves and secondary eclipses of gaseous exoplanets are diagnostic of atmospheric composition and meteorology , and the long observational baseline and high photometric precision from the Kepler Mission make its dataset well-suited for exploring phase curve variability , which provides additional insights into atmospheric dynamics .
Observations of the hot Jupiter Kepler-76b span more than 1,000 days , providing an ideal dataset to search for atmospheric variability .
In this study , we find that Kepler-76b ’ s secondary eclipse , with a depth of 87 \pm 6 parts-per-million ( ppm ) , corresponds to an effective temperature of 2,830 ^ { +50 } _ { -30 } K. Our results also show clear indications of variability in Kepler-76b ’ s atmospheric emission and reflectivity , with the phase curve amplitude typically 50.5 \pm 1.3 ppm but varying between 35 and 70 ppm over tens of days .
As is common for hot Jupiters , Kepler-76b ’ s phase curve shows a discernible offset of \left ( 9 \pm 1.3 \right ) ^ { \circ } eastward of the sub-stellar point and varying in concert with the amplitude .
These variations may arise from the advance and retreat of thermal structures and cloud formations in Kepler-76b ’ s atmosphere ; the resulting thermal perturbations may couple with the super-rotation expected to transport aerosols , giving rise to a feedback loop .
Looking forward , the TESS Mission can provide new insight into planetary atmospheres , with good prospects to observe both secondary eclipses and phase curves among targets from the mission . TESS ’ s increased sensitivity in red wavelengths as compared to Kepler means that it will probably probe different aspects of planetary atmospheres .