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First exo-atmospheric characterization from TESS data unveiled at SAC

SAC has characterized the atmosphere of an exoplanet using TESS data and in a new paper researchers present their findings.

2020.05.01 | Michaela Louise Thulesen

This is an artist’s concept of a hot Jupiter exoplanet. Image credit: NASA / ESA / G. Bacon, STScI.

For the first time SAC publishes a paper on arXiv about the study of exoplanet atmospheres using TESS data. In the paper, which is also accepted for publication in Astronomy & Astrophysics, the researchers present the detection and characterization of the full-orbit phase curve and secondary eclipse of the ultra-hot Jupiter WASP-33b observed by TESS, along with the pulsation spectrum of the host star.

In the study, the researchers find that WASP-33b's host star, of delta Scuti type, shows non-radial pulsations in the milli-magnitude regime, with periods comparable to that of the primary transit. Analyzing TESS photometry the researchers found 29 pulsation frequencies, that were used to clean the light curve and study the planet. A secondary eclipse depth of 305.8 +/- 35.5 parts-per-million (ppm) is reported in the paper, along with an amplitude of the phase curve of 100.4 +/- 13.1 ppm and a corresponding westward offset between the region of maximum brightness and the substellar point of 28.7 +/- 7.1 degrees, making WASP-33b one of the few planets with such an offset found so far.

The researchers also determined the Bond albedo, heat recirculation efficiency, and day and night side brightness temperatures. From the detection of photometric variations due to gravitational interactions, they estimated a planet mass of M_P = 2.81 +/- 0.53 M_Jup, consistent with literature values. Analyzing the stellar pulsations in the frame of the planetary orbit, they found no signals of star-planet interactions.

Read the paper on arXiv here.

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