Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS)? V. Detection of sodium on the bloated super-Neptune WASP-166b
Date
2020-07-06Author
Seidel, J. V.
Ehrenreich, D.
Bourrier, V.
Allart, R.
Attia, O.
Hoeijmakers, H. J.
Lendl, M.
Linder, E.
Wyttenbach, A.
Astudillo Defru, Nicola
Bayliss, D.
Cegla, H. M.
Heng, Kevin
Lavie, B.
Lovis, C.
Melo, C.
Pepe, F.
dos Santos, L. A.
Ségransan, D.
Udry, S.
Publisher
Astronomy & AstrophysicsDescription
Artículo de publicación ISIMetadata
Show full item recordAbstract
Planet formation processes or evolution mechanisms are surmised to be at the origin of the hot Neptune desert. Studying exoplanets currently living within or at the edge of this desert could allow disentangling the respective roles of formation and evolution. We present the HARPS transmission spectrum of the bloated super-Neptune WASP-166b, located at the outer rim of the Neptune desert. Neutral sodium is detected at the 3.4σ level (0.455 ± 0.135 %), with a tentative indication of line broadening, which could be caused by winds blowing sodium farther into space, a possible manifestation of the bloated character of these highly irradiated worlds. We put this detection into context with previous work claiming a non-detection of sodium in the same observations and show that the high noise in the trace of the discarded stellar sodium lines was responsible for the non-detection. We highlight the impact of this low signal-to-noise remnant on detections for exoplanets similar to WASP-166b.