TOI-908 : a planet at the edge of the Neptune desert transiting a G-type star
Abstract
We present the discovery of an exoplanet transiting TOI-908 (TIC-350153977) using data from TESS sectors 1, 12, 13, 27, 28 and 39. TOI-908 is a T = 10.7 mag G-dwarf (Teff = 5626 ± 61 K) solar-like star with a mass of 0.950 ± 0.010 M⊙ and a radius of 1.028 ± 0.030 R⊙. The planet, TOI-908 b, is a 3.18 ± 0.16 R⊕ planet in a 3.18 day orbit. Radial velocity measurements from HARPS reveal TOI-908 b has a mass of approximately 16.1 ± 4.1 M⊕, resulting in a bulk planetary density of 2.7+0.2-0.4 g cm-3. TOI-908 b lies in a sparsely-populated region of parameter space known as the Neptune desert. The planet likely began its life as a sub-Saturn planet before it experienced significant photoevaporation due to X-rays and extreme ultraviolet radiation from its host star, and is likely to continue evaporating, losing a significant fraction of its residual envelope mass.
Citation
Hawthorn , F , Bayliss , D , Armstrong , D J , Fernández , J F , Osborn , A , Sousa , S G , Adibekyan , V , Davoult , J , Collins , K A , Alibert , Y , Barros , S C C , Bouchy , F , Brogi , M , Ciardi , D R , Daylan , T , Mena , E D , Demangeon , O D S , Díaz , R F , Gan , T , Horne , K , Hoyer , S , Levine , A M , Lillo-Box , J , Nielsen , L D , Osborn , H P , Ricker , G R , Rodrigues , J , Santos , N C , Schwarz , R P , Seager , S , Bell , J S , Shporer , A , Stockdale , C , Strøm , P A , Tenenbaum , P , Udry , S , Wheatley , P J , Winn , J N & Ziegler , C 2023 , ' TOI-908 : a planet at the edge of the Neptune desert transiting a G-type star ' , Monthly Notices of the Royal Astronomical Society , vol. 524 , no. 3 , pp. 3877–3893 . https://doi.org/10.1093/mnras/stad1840
Publication
Monthly Notices of the Royal Astronomical Society
Status
Peer reviewed
ISSN
0035-8711Type
Journal article
Description
Funding: FH is supported by an STFC studentship. JFF is supported by an STFC studentship. AO is supported by an STFC studentship. This work was supported by the UKRI Frontier research scheme (EP/X027562/1). DJA is supported by UKRI through the STFC (ST/R00384X/1) and EPSRC (EP/X027562/1). This work was supported by Fundação para a Ciência e a Tecnologia (FCT) and Fundo Europeu de Desenvolvimento Regional (FEDER) via COMPETE2020 through the research grants UIDB/04434/2020, UIDP/04434/2020. JL-B acknowledges financial support received from "la Caixa" Foundation (ID 100010434) and from the European Unions Horizon 2020 research and innovation programme under the Marie Slodowska-Curie grant agreement No 847648, with fellowship code LCF/BQ/PI20/11760023. This research has also been partly funded by the Spanish State Research Agency (AEI) Project No.PID2019-107061GB-C61. YA and JD acknowledge the support of the Swiss National Fund under grant 200020-172746. MB acknowledges support from the STFC research grant ST/T000406/1. SH acknowledges CNES funding through the grant 837319.Collections
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