KMT-2021-BLG-0912Lb: a microlensing super Earth around a K-type star

The light curve of the microlensing event KMT-2021-BLG-0912 exhibits a very short anomaly relative to single-lens single-source form. We investigate for purpose identifying origin anomaly. model under various interpretations. From this, we find four solutions, in which three solutions are found assumption that lens is composed two masses (2L1S models), and other solution source comprised binary-star system (1L2S model). 1L2S ruled out based on contradiction faint companion bigger than its primary, one 2L1S excluded from combination relatively worse fit, blending constraint, lower overall probability, leaving surviving with planet/host mass ratios $q\sim 2.8\times 10^{-5}$ $\sim 1.1\times 10^{-5}$. A subtle central deviation supports possibility tertiary component, either binary host large or small separation second planet lying near Einstein ring, but it difficult claim secure detection due marginal fit improvement, lack consistency among different data sets, difficulty uniquely specifying nature component. With observables event, estimated (6.9~M_\oplus, 0.75~M_\odot)$ according (2.8~M_\oplus, 0.80~M_\odot)$ solution, indicating super Earth around K-type star, regardless solution.