Bibcode
de Leon, J. P.; Livingston, J. H.; Jenkins, J. S.; Vines, J. I.; Wittenmyer, R. A.; Clark, J. T.; Winn, J. I. M.; Addison, B.; Ballard, S.; Bayliss, D.; Beichman, C.; Benneke, B.; Berardo, D. A.; Bowler, B. P.; Brown, T.; Bryant, E. M.; Christiansen, J.; Ciardi, D.; Collins, K. A.; Collins, K. I.; Crossfield, I.; Deming, D.; Dragomir, D.; Dressing, C. D.; Fukui, A.; Gan, T.; Giacalone, S.; Gill, S.; Gorjian, V.; González Alvarez, E.; Hesse, K.; Horner, J.; Howell, S. B.; Jenkins, J. M.; Kane, S. R.; Kendall, A.; Kielkopf, J. F.; Kreidberg, L.; Latham, D. W.; Liu, H.; Lund, M. B.; Matson, R.; Matthews, E.; Mengel, M. W.; Morales, F.; Mori, M.; Narita, N.; Nishiumi, T.; Okumura, J.; Plavchan, P.; Quinn, S.; Rabus, M.; Ricker, G.; Rudat, A.; Schlieder, J.; Schwarz, R. P.; Seager, S.; Shporer, A.; Smith, A. M. S.; Stassun, K.; Tamura, M.; Tan, T. G.; Tinney, C.; Vanderspek, R.; Werner, M. W.; West, R. G.; Wright, D.; Zhang, H.; Zhou, G.
Bibliographical reference
Monthly Notices of the Royal Astronomical Society
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6
2023
Citations
4
Refereed citations
4
Description
Transiting exoplanets orbiting young nearby stars are ideal laboratories for testing theories of planet formation and evolution. However, to date only a handful of stars with age <1 Gyr have been found to host transiting exoplanets. Here we present the discovery and validation of a sub-Neptune around HD 18599 , a young (300 Myr), nearby (d = 40 pc) K star. We validate the transiting planet candidate as a bona fide planet using data from the TESS , Spitzer , and Gaia missions, ground-based photometry from IRSF , LCO , PEST , and NGTS , speckle imaging from Gemini, and spectroscopy from CHIRON , NRES , FEROS , and MINERVA-Australis . The planet has an orbital period of 4.13 d , and a radius of 2.7 R⊕ . The RV data yields a 3-σ mass upper limit of 30.5 M⊕ which is explained by either a massive companion or the large observed jitter typical for a young star. The brightness of the host star (V~9 mag) makes it conducive to detailed characterization via Doppler mass measurement which will provide a rare view into the interior structure of young planets.