NGTS-10b: the shortest period hot Jupiter yet discovered

• Published in: Monthly notices of the Royal Astronomical Society 2020-03, Vol.493 (1), p.126-140
• Main Authors: McCormac, James, Gillen, Edward, Jackman, James A G, Brown, David J A, Bayliss, Daniel, Wheatley, Peter J, Anderson, David R, Armstrong, David J, Bouchy, François, Briegal, Joshua T, Burleigh, Matthew R, Cabrera, Juan, Casewell, Sarah L, Chaushev, Alexander, Chazelas, Bruno, Chote, Paul, Cooke, Benjamin F, Costes, Jean C, Csizmadia, Szilárd, Eigmüller, Philipp, Erikson, Anders, Foxell, Emma, Gänsicke, Boris T, Goad, Michael R, Günther, Maximilian N, Hodgkin, Simon T, Hooton, Matthew J, Jenkins, James S, Lambert, Gregory, Lendl, Monika, Longstaff, Emma, Louden, Tom, Moyano, Maximiliano, Nielsen, Louise D, Pollacco, Don, Queloz, Didier, Rauer, Heike, Raynard, Liam, Smith, Alexis M S, Smalley, Barry, Soto, Maritza, Turner, Oliver, Udry, Stéphane, Vines, Jose I, Walker, Simon R, Watson, Christopher A, West, Richard G
• Format: Article
• Language: English
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/staa115

ABSTRACT We report the discovery of a new ultrashort period (USP) transiting hot Jupiter from the Next Generation Transit Survey (NGTS). NGTS-10b has a mass and radius of $2.162\, ^{+0.092}_{-0.107}$ MJ and $1.205\, ^{+0.117}_{-0.083}$ RJ and orbits its host star with a period of 0.7668944 ± 0.0000003 d, making it the shortest period hot Jupiter yet discovered. The host is a 10.4 ± 2.5 Gyr old K5V star (Teff = 4400 ± 100 K) of Solar metallicity ([Fe/H] = −0.02 ± 0.12 dex) showing moderate signs of stellar activity. NGTS-10b joins a short list of USP Jupiters that are prime candidates for the study of star–planet tidal interactions. NGTS-10b orbits its host at just 1.46 ± 0.18 Roche radii, and we calculate a median remaining inspiral time of 38 Myr and a potentially measurable orbital period decay of 7 s over the coming decade, assuming a stellar tidal quality factor $Q^{\prime }_{\rm s}$ =2 × 107.