Exoplanet HAT-P-18b (Her)

Discovery and References:

HAT-P-18b and HAT-P-19b: Two Low-Density Saturn-Mass Planets Transiting Metal-Rich K Stars

(J. D. Hartman, G. Á. Bakos, B. Sato, G. Torres, R. W. Noyes, D. W. Latham, G. Kovács, D. A. Fischer, A. W. Howard, J. A. Johnson, G. W. Marcy, L. A. Buchhave, G. Füresz, G. Perumpilly, B. Béky, R. P. Stefanik, D. D. Sasselov, G. A. Esquerdo, M. Everett, Z. Csubry, J. Lázár, I. Papp, P. Sári)

... report the discovery of two new transiting extrasolar planets. HAT-P-18b orbits the V=12.759 K2 dwarf star GSC 2594-00646, with a period P=5.508023+-0.000006 d, transit epoch Tc=2454715.02174+-0.00020 (BJD), and transit duration 0.1131+-0.0009 d. The host star has a mass of 0.77+-0.03 Msun, radius of 0.75+-0.04 Rsun, effective temperature 4803+-80 K, and metallicity [Fe/H]=+0.10+-0.08. The planetary companion has a mass of 0.197+-0.013 Mjup, and radius of 0.995+-0.052 Rjup yielding a mean density of 0.25+-0.04 g cm-3 ...

CCD OBSERVATIONS

Date: 2013-04-17

Differential Photometry and Light Curve with FOTODIFF