The young HD 73583 (TOI-560) planetary system: two 10-M⊕ mini-Neptunes transiting a 500-Myr-old, bright, and active K dwarf. Issue 2 (15th March 2022)

• Record Type: Journal Article
• Authors: Barragán, O; Armstrong, D J; Gandolfi, D; Carleo, I; Vidotto, A A; Villarreal D'Angelo, C; Oklopčić, A; Isaacson, H; Oddo, D; Collins, K; Fridlund, M; Sousa, S G; Persson, C M; Hellier, C; Howell, S; Howard, A; Redfield, S; Eisner, N; Georgieva, I Y; Dragomir, D; Bayliss, D; Nielsen, L D; Klein, B; Aigrain, S; Zhang, M; Teske, J; Twicken, J D; Jenkins, J; Esposito, M; Van Eylen, V; Rodler, F; Adibekyan, V; Alarcon, J; Anderson, D R; Akana Murphy, J M; Barrado, D; Barros, S C C; Benneke, B; Bouchy, F; Bryant, E M; Butler, R P; Burt, J; Cabrera, J; Casewell, S; Chaturvedi, P; Cloutier, R; Cochran, W D; Crane, J; Crossfield, I; Crouzet, N; Collins, K I; Dai, F; Deeg, H J; Deline, A; Demangeon, O D S; Dumusque, X; Figueira, P; Furlan, E; Gnilka, C; Goad, M R; Goffo, E; Gutiérrez-Canales, F; Hadjigeorghiou, A; Hartman, Z; Hatzes, A P; Harris, M; Henderson, B; Hirano, T; Hojjatpanah, S; Hoyer, S; Kabáth, P; Korth, J; Lillo-Box, J; Luque, R; Marmier, M; Močnik, T; Muresan, A; Murgas, F; Nagel, E; Osborne, H L M; Osborn, A; Osborn, H P; Palle, E; Raimbault, M; Ricker, G R; Rubenzahl, R A; Stockdale, C; Santos, N C; Scott, N; Schwarz, R P; Shectman, S; Raimbault, M; Seager, S; Ségransan, D; Serrano, L M; Skarka, M; Smith, A M S; Šubjak, J; Tan, T G; Udry, S; Watson, C; Wheatley, P J; West, R; Winn, J N; Wang, S X; Wolfgang, A; Ziegler, C;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 514:Issue 2(2022)
• Page Start: 1606
• Page End: 1627
• Publication Date: 2022-03-15
• Subjects: techniques: photometric -- techniques: radial velocities -- planets and satellites: individual: HD 73583 (TOI-560) -- stars: activity; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stac638
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present the discovery and characterization of two transiting planets observed by TESS in the light curves of the young and bright ( V = 9.67) star HD73583 (TOI-560). We perform an intensive spectroscopic and photometric space- and ground-based follow-up in order to confirm and characterize the system. We found that HD73583 is a young (∼500 Myr) active star with a rotational period of 12.08 ± 0.11 d, and a mass and radius of 0.73 ± 0.02 M⊙ and 0.65 ± 0.02 R⊙, respectively. HD 73583 b ( Pb = $6.3980420 _{ - 0.0000062 } ^ { + 0.0000067 }$ d) has a mass and radius of $10.2 _{ - 3.1 } ^ { + 3.4 }$ M ⊕ and 2.79 ± 0.10 R ⊕, respectively, which gives a density of $2.58 _{ - 0.81 } ^ { + 0.95 }$ ${\rm g\, cm^{-3}}$ . HD 73583 c ( Pc = $18.87974 _{ - 0.00074 } ^ { + 0.00086 }$ d) has a mass and radius of $9.7 _{ - 1.7 } ^ { + 1.8 }$ M ⊕ and $2.39 _{ - 0.09 } ^ { + 0.10 }$ R ⊕, respectively, which translates to a density of $3.88 _{ - 0.80 } ^ { + 0.91 }$ ${\rm g\, cm^{-3}}$ . Both planets are consistent with worlds made of a solid core surrounded by a volatile envelope. Because of their youth and host star brightness, they both are excellent candidates to perform transmission spectroscopy studies. We expect ongoing atmospheric mass-loss for both planets caused by stellar irradiation. We estimate that the detection of evaporating signatures on H and He would be challenging, but doable with present and future instruments.