Please use this identifier to cite or link to this item:
Title: Nightside condensation of iron in an ultrahot giant exoplanet
Authors: Ehrenreich, D.
Lovis, C.
Allart, R.
Zapatero Osorio, M. R.
Pepe, F.
Cristiani, S.
Rebolo, R.
Santos, N. C.
Borsa, F.
Demangeon, O. D. S.
Dumusque, X.
González Hernández, J. I.
Casasayas Barris, N.
Séngrasan, D.
Sousa, S.
Abreu, M.
Adibekyan, V.
Affolter, M.
Allende Prieto, C.
Alibert, Y.
Aliverti, M.
Alves, D.
Amate, M.
Ávila, G.
Baldini, V.
Bandy, T.
Benz, W.
Bianco, A.
Bolmont, É.
Bouchy, F.
Bourrier, V.
Broeg, C.
Cabral, A.
Calderone, G.
Pallé, E.
Cegla, H. M.
Cirami, R.
Coelho, João M. P.
Conconi, P.
Coretti, I.
Cumani, C.
Cupani, G.
Dekker, H.
Delabre, B.
Deiries, S.
D´Odorico, V.
Di Marcoantonio, P.
Figueira, P.
Fragoso, A.
Genolet, L.
Genoni, M.
Génova Santos, R.
Harada, N.
Hughes, I.
Iwert, O.
Kerber, F.
Knudstrup, J.
Landoni, M.
Lavie, B.
Lizon, J. L.
Lendl, M.
Lo Curto, G.
Maire, C.
Manescau, A.
Martins, C. J. A. P.
Mégevand, D.
Mehner, A.
Micela, G.
Modigliani, A.
Molaro, P.
Monteiro, M.
Monteiro, M. A.
Moschetti, M.
Muller, N.
Nunes, N.
Oggioni, L.
Oliveira, A.
Pariani, G.
Pasquini, L.
Poretti, E.
Rasilla, J. L.
Redaelli, E.
Riva, M.
Santana Tschudi, S.
Santin, P.
Santos, P.
Segovia Milla, A.
Seidel, J. V.
Sosnowska, D.
Sozzetti, A.
Spanò, P.
Suárez Mascareño, A.
Tabernero, H.
Tenegi, F.
Udry, S.
Zanutta, A.
Zerbi, Filippo M.
Issue Date: 11-Mar-2020
Publisher: Nature Research Journals
DOI: 10.1038/s41586-020-2107-1
Published version:
Citation: Nature 580: 597-601(2020)
Abstract: Ultrahot giant exoplanets receive thousands of times Earth’s insolation1,2. Their high-temperature atmospheres (greater than 2,000 kelvin) are ideal laboratories for studying extreme planetary climates and chemistry3,4,5. Daysides are predicted to be cloud-free, dominated by atomic species6 and much hotter than nightsides5,7,8. Atoms are expected to recombine into molecules over the nightside9, resulting in different day and night chemistries. Although metallic elements and a large temperature contrast have been observed10,11,12,13,14, no chemical gradient has been measured across the surface of such an exoplanet. Different atmospheric chemistry between the day-to-night (‘evening’) and night-to-day (‘morning’) terminators could, however, be revealed as an asymmetric absorption signature during transit4,7,15. Here we report the detection of an asymmetric atmospheric signature in the ultrahot exoplanet WASP-76b. We spectrally and temporally resolve this signature using a combination of high-dispersion spectroscopy with a large photon-collecting area. The absorption signal, attributed to neutral iron, is blueshifted by −11 ± 0.7 kilometres per second on the trailing limb, which can be explained by a combination of planetary rotation and wind blowing from the hot dayside16. In contrast, no signal arises from the nightside close to the morning terminator, showing that atomic iron is not absorbing starlight there. We conclude that iron must therefore condense during its journey across the nightside.
Description: D.E., C.L. and R.A. led the data analysis and interpretation. D.E. wrote the paper with contributions from R.A. C.L. led the development of the data reduction pipeline. M.R.Z.O. coordinated the observations and scientific work and performed the first-epoch observation. F.P., S.C., R.R. and N.C.S. led the ESPRESSO consortium and building of the instrument. J.I.G.H. performed the second-epoch observation. F. Borsa, O.D., E. Pallé, N.C.S., E.B., V. Bourrier, H.M.C., N.C.-B., J.V.S. and H.T. brought decisive contributions to the interpretation. N.C.-B. performed an independent data analysis. S.S. performed the stellar parameter analysis. X.D. created the CCF mask and retrieved the list of its atomic lines. N.H. made the radial velocity retrieval. D. Ségransan provided support with DACE. B.L. provided the nested sampling algorithm for the analysis. M. Lendl derived the transit ephemeris. V.A., C.A.P., Y.A., F. Bouchy, V.D., P.F., R.G.S., C.J.A.P.M., A. Mehner, G.M., P.M., N.N., G.L.C., E. Poretti, A.S., A. Suárez Mascareño and S.U. participated in the scientific preparation and target selection for these observations. The other co-authors provided key contributions to the instrumental, software and operational development of ESPRESSO. All co-authors read and commented the manuscript.
E-ISSN: 1476-4687
ISSN: 0028-0836
Appears in Collections:(CAB) Artículos

Files in This Item:
File Description SizeFormat 
acceso-restringido.pdf221,73 kBAdobe PDFThumbnail

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.