We analyze the very short Einstein timescale ( t _ { E } \simeq 7 { hr } ) event KMT-2019-BLG-2073 .
Making use of the pronounced finite-source effects generated by the clump-giant source , we measure the Einstein radius \theta _ { E } \simeq 4.8 \mu { as } , and so infer a mass M = 59 M _ { \oplus } ( \pi _ { rel } / 16 \mu { as } ) ^ { -1 } , where \pi _ { rel } is the lens-source relative parallax .
We find no significant evidence for a host of this planetary mass object , though one could be present at sufficiently wide separation .
If so , it would be detectable after about 10 years .
This is the fourth isolated microlens with a measured Einstein radius \theta _ { E } < 10 \mu { as } , which we argue is a useful threshold for a “ likely free-floating planet ( FFP ) ” candidate .
We outline a new approach to constructing a homogeneous sample of giant-star finite-source/point-lens ( FSPL ) events , within which the subsample of FFP candidates can be statistically analyzed .
We illustrate this approach using 2019 KMTNet data and show that there is a large \theta _ { E } gap between the two FFP candidates and the 11 other FSPL events .
We argue that such sharp features are more identifiable in a sample selected on \theta _ { E } compared to the traditional approach of identifying candidates based on short t _ { E } .