NGTS-4b: A sub-Neptune Transiting in the Desert

Autor: West, Richard G., Gillen, Edward, Bayliss, Daniel, Burleigh, Matthew R., Delrez, Laetitia, Günther, Maximilian N., Hodgkin, Simon T., Jackman, James A. G., Jenkins, James S., King, George, McCormac, James, Nielsen, Louise D., Raynard, Liam, Smith, Alexis M. S., Soto, Maritza, Turner, Oliver, Wheatley, Peter J., Almleaky, Yaseen, Armstrong, David J., Belardi, Claudia, Bouchy, François, Briegal, Joshua T., Burdanov, Artem, Cabrera, Juan, Casewel, Sarah L., Chaushev, Alexander, Chazelas, Bruno, Chote, Paul, Cooke, Benjamin F., Csizmadia, Szilard, Ducrot, Elsa, Eigmüller, Philipp, Erikson, Anders, Foxell, Emma, Gänsicke, Boris T., Gillon, Michaël, Goad, Michael R., Jehin, Emmanuël, Lambert, Gregory, Longstaff, Emma S., Louden, Tom, Moyano, Maximiliano, Murray, Catriona, Pollacco, Don, Queloz, Didier, Rauer, Heike, Sohy, Sandrine, Thompson, Samantha J., Udry, Stéphane, Walker, Simon. R., Watson, Christopher A.
Rok vydání: 2018
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1093/mnras/stz1084
Popis: We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34d orbit. NGTS-4b has a mass M=$20.6\pm3.0$M_E and radius R=$3.18\pm0.26$R_E, which places it well within the so-called "Neptunian Desert". The mean density of the planet ($3.45\pm0.95$g/cm^3) is consistent with a composition of 100% H$_2$O or a rocky core with a volatile envelope. NGTS-4b is likely to suffer significant mass loss due to relatively strong EUV/X-ray irradiation. Its survival in the Neptunian desert may be due to an unusually high core mass, or it may have avoided the most intense X-ray irradiation by migrating after the initial activity of its host star had subsided. With a transit depth of $0.13\pm0.02$%, NGTS-4b represents the shallowest transiting system ever discovered from the ground, and is the smallest planet discovered in a wide-field ground-based photometric survey.
Comment: Submitted to MNRAS
Databáze: arXiv
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