Title: MOA Data Reveal a New Mass, Distance, and Relative Proper Motion for Planetary System OGLE-2015-BLG-0954L,
Abstract: We present the MOA Collaboration light curve data for planetary microlensing
event OGLE-2015-BLG-0954, which was previously announced in a paper by the
KMTNet and OGLE Collaborations. The MOA data cover the caustic exit, which was
not covered by the KMTNet or OGLE data, and they provide a more reliable
measurement of the finite source effect. The MOA data also provide a new source
color measurement that reveals a lens-source relative proper motion of
$\mu_{\rm rel} = 11.8\pm 0.8\,$mas/yr, which compares to the value of $\mu_{\rm
rel} = 18.4\pm 1.7\,$mas/yr reported in the KMTNet-OGLE paper. This new MOA
value for $\mu_{\rm rel}$ has an a priori probability that is a factor of $\sim
100$ times larger than the previous value, and it does not require a lens
system distance of $D_L < 1\,$kpc. Based on the corrected source color, we find
that the lens system consists of a planet of mass $3.4^{+3.7}_{-1.6} M_{\rm
Jup}$ orbiting a $0.30^{+0.34}_{-0.14}M_\odot$ star at an orbital separation of
$2.1^{+2.2}_{-1.0}\,$AU and a distance of $1.2^{+1.1}_{-0.5}\,$kpc.