The CARMENES search for exoplanets around M dwarfs: LP 714-47 b (TOI 442.01): Populating the Neptune desert
Creators: name: Collins, K.A.
name: Pallé, E.
name: Howell, S.
name: Shectman, S.
name: Huber, D.
name: Chontos, A.
name: Christiansen, J.L.
name: Benneke, B.
name: Bitsch, B.
name: Jehin, E.
name: Jensen, E.L.N.
name: Kreidberg, L.
name: Chintada, A.
name: Chaturvedi, P.
name: Esparza-Borges, E.
name: Muirhead, P.S.
name: Daylan, T.
name: Mann, A.W.
name: Rose, M.E.
name: Dragomir, D.
name: Zechmeister, M.
name: Livingston, J.
name: Oshagh, M.
name: Schlieder, J.
name: Rodríguez-López, C.
name: Kaminski, A.
name: Schweitzer, A.
name: Matson, R.A.
name: Twicken, J.D.
name: Crane, J.D.
name: Senavcl, H.V.
name: Pozuelos, F.J.
name: Caballero, J.A.
name: Feng, F.
name: Barkaoui, K.
name: Fulton, B.
name: Flowers, E.E.
name: Amado, P.J.
name: Narita, N.
name: Murgas, F.
name: Kielkopf, J.F.
name: Cifuentes, C.
name: Latham, D.W.
name: Wang, S.X.
name: Nandakumar, S.
name: Yllmaz, M.
name: Pollacco, D.
name: Weiss, L.M.
name: Hellier, C.
name: Gonzales, E.
name: Parviainen, H.
name: Hidalgo, D.
name: Kossakowski, D.
name: Jenkins, J.M.
name: Ribas, I.
name: Robertson, P.
name: Tanner, A.
name: Ricker, G.
name: Collins, K.I.
name: Luque, R.
name: Vanderspek, R.
name: Reiners, A.
name: Lillo-Box, J.
name: Reefe, M.
name: Benkhaldoun, Z.
name: Hatzes, A.P.
name: Zohrabi, F.
name: Soubkiou, A.
name: Zapatero Osorio, M.R.
name: Plavchan, P.
name: Kosiarek, M.R.
name: Cale, B.
name: Crossfield, I.J.M.
name: Schlecker, M.
name: Bauer, F.F.
name: Aceituno, J.
name: Barbieri, M.
name: Batalha, N.M.
name: Morales, J.C.
name: Butler, R.P.
name: Louie, D.
name: Caldwell, D.A.
name: Gillon, M.
name: Stassun, K.
name: Geneser, C.
name: Giacalone, S.
name: Kane, S.R.
name: Nowak, G.
name: Quirrenbach, A.
name: Teske, J.
name: Roy, A.
name: Mocnik, T.
name: Madrigal-Aguado, A.
name: Lafarga, M.
name: Cortés-Contreras, M.
name: Burt, J.
name: Beichman, C.
name: Kemmer, J.
name: Kürster, M.
name: Klahr, H.
name: Berberian, J.
name: Espinoza, N.
name: Evans, P.
name: Fukui, A.
name: Matthews, E.
name: Kawauchi, K.
name: Seager, S.
name: Passegger, V.M.
name: Villasenor, J.
name: Winn, J.
name: Gaidos, E.
name: Wittrock, J.
name: Isaacson, H.
name: Furlan, E.
name: Ciardi, D.R.
name: Gorjian, V.
name: Dreizler, S.
name: Howard, A.W.
name: Combs, D.
name: Jeffers, S.V.
name: Lalitha, S.
Publisher: name: EDP Sciences
Year: 2020

description: We report the discovery of a Neptune-like planet (LP 714-47 b, P = 4.05204 d, mb = 30.8 ± 1.5Mpdbl, Rb = 4.7 ± 0.3 Rpdbl) located in the "hot Neptune desert". Confirmation of the TESS Object of Interest (TOI 442.01) was achieved with radial-velocity follow-up using CARMENES, ESPRESSO, HIRES, iSHELL, and PFS, as well as from photometric data using TESS, Spitzer, and ground-based photometry from MuSCAT2, TRAPPIST-South, MONET-South, the George Mason University telescope, the Las Cumbres Observatory Global Telescope network, the El Sauce telescope, the TÜBITAK National Observatory, the University of Louisville Manner Telescope, and WASP-South. We also present high-spatial resolution adaptive optics imaging with the Gemini Near-Infrared Imager. The low uncertainties in the mass and radius determination place LP 714-47 b among physically well-characterised planets, allowing for a meaningful comparison with planet structure models. The host star LP 714-47 is a slowly rotating early M dwarf (Teff = 3950 ± 51 K) with a mass of 0.59 ± 0.02Mpdbl and a radius of 0.58 ± 0.02Rpdbl. From long-term photometric monitoring and spectroscopic activity indicators, we determine a stellar rotation period of about 33 d. The stellar activity is also manifested as correlated noise in the radial-velocity data. In the power spectrum of the radial-velocity data, we detect a second signal with a period of 16 days in addition to the four-day signal of the planet. This could be shown to be a harmonic of the stellar rotation period or the signal of a second planet. It may be possible to tell the difference once more TESS data and radial-velocity data are obtained.