MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detection

We analyze MOA-2010-BLG-311, a high magnification (Amax > 600) microlensing event with complete data coverage over the peak, making it very sensitive to planetary signals. We fit this event with both a point lens and a two-body lens model and find that the two-body lens model is a better fit but with only Δχ2 ∼ 80. The preferred mass ratio between the lens star and its companion is q = 10−3.7 ± 0.1, placing the candidate companion in the planetary regime. Despite the formal significance of the planet, we show that because of systematics in the data the evidence for a planetary companion to the lens is too tenuous to claim a secure detection. When combined with analyses of other high-magnification events, this event helps empirically define the threshold for reliable planet detection in high-magnification events, which remains an open question.

C. H. Ling | J. Beaulieu | E. Kerins | M. Penny | G. Scarpetta | D. Maoz | E. Bachelet | B. Gaudi | D. Bennett | R. Poleski | Avi Shporer | R. Street | D. Depoy | K. Ulaczyk | M. Burgdorf | J. Surdej | B. Shappee | S. Dong | L. Monard | R. Pogge | J. Menzies | I. Steele | P. Yock | L. Mancini | K. Alsubai | D. Bramich | U. Jørgensen | K. Horne | M. Dominik | K. Harpsoe | C. Liebig | S. Novati | D. Ricci | A. Fukui | F. Abe | K. Sahu | T. Gerner | S. Rahvar | A. Udalski | M. Szymański | M. Kubiak | C. Botzler | L. Hung | C. Snodgrass | T. Beatty | C. Henderson | S. Kaspi | J. Saders | F. Finet | V. Bozza | P. Browne | P. Dodds | S. Hardis | T. Hinse | M. Hundertmark | N. Kains | M. Mathiasen | S. Proft | S. Schafer | F. Schonebeck | J. Southworth | M. Zub | J. Skowron | P. Fouqué | G. Pietrzynski | L. Wyrzykowski | I. Soszyński | J. Caldwell | W. Sweatman | R. Zellem | D. Sullivan | Y. Itow | Y. Matsubara | D. Prester | A. Williams | P. Chote | F. Hessman | P. Tristram | M. Nola | Y. Tsapras | M. Bos | J. Marquette | M. Albrow | J. Yee | C. Han | C.-U. Lee | Y. Shvartzvald | B.-G. Park | K. Masuda | E. Corrales | J. Greenhill | D. Polishook | J. Donatowicz | T. Sumi | I. Bond | N. Rattenbury | A. Cassan | K. Furusawa | C. Ling | N. Miyake | K. Ohnishi | To. Saito | M. Freeman | D. Suzuki | K. Wada | G. Christie | J. Mccormick | D. Moorhouse | T. Natusch | G. Thornley | C. Coutures | V. Batista | P. Harris | R. Bowens-Rubin | D. Wouters | N. Klein | J. Drummond | R. Martin | W. Allen | D. Kubas | S. Brillant | A. Cole | S. Dieters | A. Gould | C. S. Bennett | E. Gorbikov | C. Bennett | J. Wambsgans | G. Pietrzyński | S. C. Novati | C.‐U. Lee | J. V. Saders | T. Saito | K. Wada

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