A Sub-Saturn Mass Planet, MOA-2009-BLG-319Lb

February 2011 • 2011ApJ...728..120M

Authors • Miyake, N. • Sumi, T. • Dong, Subo • Street, R. • Mancini, L. • Gould, A. • Bennett, D. P. • Tsapras, Y. • Yee, J. C. • Albrow, M. D. • Bond, I. A. • Fouqué, P. • Browne, P. • Han, C. • Snodgrass, C. • Finet, F. • Furusawa, K. • Harpsøe, K. • Allen, W. • Hundertmark, M. • Freeman, M. • Suzuki, D. • Abe, F. • Botzler, C. S. • Douchin, D. • Fukui, A. • Hayashi, F. • Hearnshaw, J. B. • Hosaka, S. • Itow, Y. • Kamiya, K. • Kilmartin, P. M. • Korpela, A. • Lin, W. • Ling, C. H. • Makita, S. • Masuda, K. • Matsubara, Y. • Muraki, Y. • Nagayama, T. • Nishimoto, K. • Ohnishi, K. • Perrott, Y. C. • Rattenbury, N. • Saito, To. • Skuljan, L. • Sullivan, D. J. • Sweatman, W. L. • Tristram, P. J. • Wada, K. • Yock, P. C. M. • MOA Collaboration • Bolt, G. • Bos, M. • Christie, G. W. • DePoy, D. L. • Drummond, J. • Gal-Yam, A. • Gaudi, B. S. • Gorbikov, E. • Higgins, D. • Hwang, K. -H. • Janczak, J. • Kaspi, S. • Lee, C. -U. • Koo, J. -R. • Kozłowski, S. • Lee, Y. • Mallia, F. • Maury, A. • Maoz, D. • McCormick, J. • Monard, L. A. G. • Moorhouse, D. • Muñoz, J. A. • Natusch, T. • Ofek, E. O. • Pogge, R. W. • Polishook, D. • Santallo, R. • Shporer, A. • Spector, O. • Thornley, G. • μFUN Collaboration • Allan, A. • Bramich, D. M. • Horne, K. • Kains, N. • Steele, I. • RoboNet Collaboration • Bozza, V. • Burgdorf, M. J. • Calchi Novati, S. • Dominik, M. • Dreizler, S. • Glitrup, M. • Hessman, F. V. • Hinse, T. C. • Jørgensen, U. G. • Liebig, C. • Maier, G. • Mathiasen, M. • Rahvar, S. • Ricci, D. • Scarpetta, G. • Skottfelt, J. • Southworth, J. • Surdej, J. • Wambsganss, J. • Zimmer, F. • MiNDSTEp Consortium • Batista, V. • Beaulieu, J. P. • Brillant, S. • Cassan, A. • Cole, A. • Corrales, E. • Coutures, Ch. • Dieters, S. • Greenhill, J. • Kubas, D. • Menzies, J. • PLANET Collaboration

Abstract • We report the gravitational microlensing discovery of a sub-Saturn mass planet, MOA-2009-BLG-319Lb, orbiting a K- or M-dwarf star in the inner Galactic disk or Galactic bulge. The high-cadence observations of the MOA-II survey discovered this microlensing event and enabled its identification as a high-magnification event approximately 24 hr prior to peak magnification. As a result, the planetary signal at the peak of this light curve was observed by 20 different telescopes, which is the largest number of telescopes to contribute to a planetary discovery to date. The microlensing model for this event indicates a planet-star mass ratio of q = (3.95 ± 0.02) × 10^-4 and a separation of d = 0.97537 ± 0.00007 in units of the Einstein radius. A Bayesian analysis based on the measured Einstein radius crossing time, t _E, and angular Einstein radius, θ_E, along with a standard Galactic model indicates a host star mass of M _L = 0.38^+0.34 _-0.18 M _sun and a planet mass of M _p = 50⁺⁴⁴ _-24 M _⊕, which is half the mass of Saturn. This analysis also yields a planet-star three-dimensional separation of a = 2.4^+1.2 _-0.6 AU and a distance to the planetary system of D _L = 6.1^+1.1 _-1.2 kpc. This separation is ~2 times the distance of the snow line, a separation similar to most of the other planets discovered by microlensing.

Links

• SIMBAD http://simbad.u-strasbg.fr/simbo.pl?bibcode=2011ApJ...728..120M
• PDF https://iopscience.iop.org/article/10.1088/0004-637X/728/2/120/pdf
• PREPRINT http://arxiv.org/abs/1010.1809
• DATA http://exoplanetarchive.ipac.caltech.edu/cgi-bin/DisplayOverview/nph-DisplayOverview?type=REFERENCE&bibcode=2011ApJ...728..120M
• ELECTR https://iopscience.iop.org/article/10.1088/0004-637X/728/2/120