Brahm, R.Jordán, A.Hartman, J. D.Bakos, G. A.Bayliss, DanielPenev, K.Zhou, Guyin (George)Ciceri, SimonaRabus, M.Espinoza, N.Mancini, L.de Val-Borro, M.Bhatti, WaqasSato, B.Tan, T. G.Csubry, Z.Buchhave, L.Henning, T.Schmidt, BrianSuc, V.Noyes, R. W.Papp, I.Lazar, J.Sari, P.2016-06-140004-6256http://hdl.handle.net/1885/102723We report the discovery of two transiting extrasolar planets by the HATSouth survey. HATS-9b orbits an old (10.8 ± 1.5 Gyr) V = 13.3 G dwarf star with a period days. The host star has a mass of 1.03 M⊙, radius of 1.503 R⊙, and effective temperature 5366 ± 70 K. The planetary companion has a mass of 0.837 <inf>Mj</inf> and radius of 1.065 R<inf>j</inf>, yielding a mean density of 0.85g cm-3. HATS-10b orbits a V = 13.1 G dwarf star with a period days. The host star has a mass of 1.1 M⊙, radius of 1.11 R⊙, and effective temperature 5880 ± 120 K. The planetary companion has a mass of 0.53 and radius of 0.97 , yielding a mean density of 0.7 g cm-3. Both planets are compact in comparison with planets receiving similar irradiation from their host stars and lie in the nominal coordinates of Field 7 of K2, but only HATS-9b falls on working silicon. Future characterization of HATS-9b with the exquisite photometric precision of the Kepler telescope may provide measurements of its reflected light signature.Development of the HATSouth project was funded by the NSF MRI grant NSF/AST-0723074, and operations have been supported by NASA grants NNX09AB29G/NNX12AH91H and internal Princeton funds. Follow-up observations have received partial support from grant NSF/AST-1108686. A.J. acknowledges support from FONDECYT project 1130857, BASAL CATA PFB-06, and project IC120009 “Millennium Institute of Astrophysics (MAS)” of the Millenium Science Initiative, Chilean Ministry of Economy. R.B. and N.E. are supported by CONICYT-PCHA/Doctorado Nacional. R.B. and N.E. acknowledge additional support from project IC120009 “Millenium Institute of Astrophysics (MAS)” of the Millennium Science Initiative, Chilean Ministry of Economy. V.S. acknowledges support form BASAL CATA PFB-06. K.P. acknowledges support from NASA grant NNX13AQ62G. Work at the Australian National University is supported by ARC Laureate Fellowship Grant FL0992131.13 pages© 2015. The American Astronomical Society. Author/s retain copyright.201510.1088/0004-6256/150/1/332016-06-14