We analyze MOA-2010-BLG-311, a high magnification (A <SUB>max</SUB> > 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 ∆χ<SUP>2</SUP> ~ 80. The preferred mass ratio between the lens star and its companion is q = 10<SUP>-3.7 ± 0.1</SUP>, 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.
Yee, J.c., Hung, L.-., Bond, I.a., Allen, W., Monard, L., Albrow, M.d., et al. (2013). MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detection. THE ASTROPHYSICAL JOURNAL, 769(1), 77 [10.1088/0004-637X/769/1/77].
MOA-2010-BLG-311: A planetary candidate below the threshold of reliable detection
Mancini L.;Ricci D.;
2013-01-01
Abstract
We analyze MOA-2010-BLG-311, a high magnification (A max > 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 ∆χ2 ~ 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
