ORCID Profile
0000-0001-9003-7699
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Publisher: EDP Sciences
Date: 30-10-2020
DOI: 10.1051/0004-6361/202039058
Abstract: WASP-127b is one of the puffiest exoplanets found to date, with a mass of only 3.4 Neptune masses, but a radius larger than that of Jupiter. It is located at the border of the Neptune desert, which describes the lack of highly irradiated Neptune-sized planets, and which remains poorly understood. Its large scale height and bright host star make the transiting WASP-127b a valuable target to characterise in transmission spectroscopy. We used combined EulerCam and TESS light curves to recalculate the system parameters. Additionally, we present an in-depth search for sodium in four transit observations of WASP-127b, obtained as part of the Hot Exoplanet Atmosphere Resolved with Transit Spectroscopy (HEARTS) survey with the High Accuracy Radial velocity Planet Searcher (HARPS) spectrograph. Two nights from this dataset were analysed independently by another team. The team claimed a detection of sodium that is incompatible with previous studies of data from both ground and space. We show that this strong sodium detection is due to contamination from telluric sodium emissions and the low signal-to-noise ratio in the core of the deep stellar sodium lines. When these effects are properly accounted for, the previous sodium signal is reduced to an absorption of 0.46 ± 0.20% (2.3 σ ), which is compatible with analyses of WASP-127b transits carried out with other instruments. We can fit a Gaussian to the D2 line, but the D1 line was not detected. This indicates an unusual line ratio if sodium exists in the atmosphere. Follow-up of WASP-127 at high resolution and with high sensitivity is required to firmly establish the presence of sodium and analyse its line shape.
Publisher: Springer Science and Business Media LLC
Date: 05-2018
DOI: 10.1038/S41586-018-0067-5
Abstract: Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable species in the atmospheres of exoplanets, especially in extended and escaping atmospheres
Publisher: EDP Sciences
Date: 05-2019
DOI: 10.1051/0004-6361/201935356
Abstract: Context. Since 1998, a planet-search around main sequence stars within 50 pc in the southern hemisphere has been underway with the CORALIE spectrograph at La Silla Observatory. Aims. With an observing time span of more than 20 yr, the CORALIE survey is able to detect long-term trends in data with masses and separations large enough to select ideal targets for direct imaging. Detecting these giant companion candidates will allow us to start bridging the gap between radial-velocity-detected exoplanets and directly imaged planets and brown dwarfs. Methods. Long-term precise Doppler measurements with the CORALIE spectrograph reveal radial-velocity signatures of massive planetary companions and brown dwarfs on long-period orbits. Results. In this paper, we report the discovery of new companions orbiting HD 181234, HD 13724, HD 25015, HD 92987 and HD 50499. We also report updated orbital parameters for HD 50499b, HD 92788b and HD 98649b. In addition, we confirm the recent detection of HD 92788c. The newly reported companions span a period range of 15.6–40.4 yr and a mass domain of 2.93–26.77 M Jup , the latter of which straddles the nominal boundary between planets and brown dwarfs. Conclusions. We report the detection of five new companions and updated parameters of four known extrasolar planets. We identify at least some of these companions to be promising candidates for imaging and further characterisation.
Publisher: American Astronomical Society
Date: 14-08-2020
Publisher: Oxford University Press (OUP)
Date: 10-07-2019
Abstract: We report the discovery of WASP-166b, a super-Neptune planet with a mass of 0.1 MJup (1.9 MNep) and a bloated radius of 0.63 RJup. It transits a V = 9.36, F9V star in a 5.44-d orbit that is aligned with the stellar rotation axis (sky-projected obliquity angle λ = 3 ± 5 deg). Variations in the radial-velocity measurements are likely the result of magnetic activity over a 12-d stellar rotation period. WASP-166b appears to be a rare object within the ‘Neptune desert’.
Location: United States of America
No related grants have been discovered for Aurélien Wyttenbach.