NGTS-6b: an ultrashort period hot-Jupiter orbiting an old K dwarf
Jackman, James A. G.; Wheatley, Peter J.; Bayliss, Daniel; Moyano, Maximiliano; Cabrera, Juan; Eigmüller, Philipp; Erikson, Anders; Rauer, Heike; Casewell, Sarah L.; Gill, Samuel; Goad, Michael R.; Burleigh, Matthew R.; Gillen, Edward; Jenkins, James S.; McCormac, James; Udry, Stéphane; Vines, Jose I.; West, Richard G.; Smith, Alexis M. S.; Bryant, Edward M.; Queloz, Didier; Watson, Christopher A.; Bouchy, François; Chaushev, Alexander; Csizmadia, Szilárd; Foxell, Emma; Louden, Tom; Nielsen, Louise D.; Raynard, Liam; Titz-Weider, Ruth; Pollacco, Don; Acton, Jack S.; Tilbrook, Rosanna H.; Turner, Oliver; King, George W.; Cooke, Benjamin F.; Belardi, Claudia; Soto, Maritza G.; Walker, Simon R.; Briegal, Joshua
Chile, United Kingdom, Switzerland, Germany
Abstract
We report the discovery of a new ultrashort period hot Jupiter from the Next Generation Transit Survey. NGTS-6b orbits its star with a period of 21.17 h, and has a mass and radius of 1.330^{+0.024}_{-0.028}MJ and 1.271^{+0.197}_{-0.188}RJ, respectively, returning a planetary bulk density of 0.711^{+0.214}_{-0.136} g cm-3. Conforming to the currently known small population of ultrashort period hot Jupiters, the planet appears to orbit a metal-rich star ([Fe/H] = +0.11 ± 0.09 dex). Photoevaporation models suggest the planet should have lost 5 per cent of its gaseous atmosphere over the course of the 9.6 Gyr of evolution of the system. NGTS-6b adds to the small, but growing list of ultrashort period gas giant planets, and will help us to understand the dominant formation and evolutionary mechanisms that govern this population.