Document Type
Article
Publication Date
7-1-2015
Abstract
We report the discovery of KELT-7b, a transiting hot Jupiter with a mass of 1.28 ± 0.18MJ, radius of 1.533 0.0470.046RJ, and an orbital period of 2.7347749 ± 0.0000039 days. The bright host star (HD 33643; KELT-7) is an F-star with V = 8.54, Teff= 6789 4950 K, [Fe/H] 0.139 0.081 = -0.075, and log g = 4.149 ± 0.019. It has a mass of 1.535 0.0540.066 Me, a radius of 1.732 0.0450.043 Re, and is the fifth most massive, fifth hottest, and the ninth brightest star known to host a transiting planet. It is also the brightest star around which Kilodegree Extremely Little Telescope (KELT) has discovered a transiting planet. Thus, KELT-7b is an ideal target for detailed characterization given its relatively low surface gravity, high equilibrium temperature, and bright host star. The rapid rotation of the star (73 ± 0.5 km s-1) results in a RossiterMcLaughlin effect with an unusually large amplitude of several hundred m s-1. We find that the orbit normal of the planet is likely to be well-aligned with the stellar spin axis, with a projected spin orbit alignment of = 9.7 ± 5. 2. This is currently the second most rapidly rotating star to have a reflex signal (and thus mass determination) due to a planetary companion measured.
Publication Source (Journal or Book title)
Astronomical Journal
Recommended Citation
Bieryla, A., Collins, K., Beatty, T., Eastman, J., Siverd, R., Pepper, J., Gaudi, B., Stassun, K., Cañas, C., Latham, D., Buchhave, L., Sanchis-Ojeda, R., Winn, J., Jensen, E., Kielkopf, J., McLeod, K., Gregorio, J., Colón, K., Street, R., Ross, R., Penny, M., Mellon, S., Oberst, T., Fulton, B., Wang, J., Berlind, P., Calkins, M., Esquerdo, G., Depoy, D., Gould, A., Marshall, J., Pogge, R., & Trueblood, M. (2015). KELT-7b: A HOT JUPITER TRANSITING A BRIGHT v = 8.54 RAPIDLY ROTATING F-STAR. Astronomical Journal, 150 (1) https://doi.org/10.1088/0004-6256/150/1/12