KMT-2022-BLG-0475Lb and KMT-2022-BLG-1480Lb: Microlensing ice giants detected via non-caustic-crossing channel

Abstract

We investigate the microlensing data collected in the 2022 season from the high-cadence microlensing surveys in order to find weak signals produced by planetary companions to lenses. From these searches, we find that two lensing events KMT-2022-BLG-0475 and KMT-2022-BLG-1480 exhibit weak short-term anomalies. From the detailed modeling of the lensing light curves, we identify that the anomalies are produced by planetary companions with a mass ratio to the primary of $q\sim 1.8\times 10^{-4}$ for KMT-2022-BLG-0475L and a ratio $q\sim 4.3\times 10^{-4}$ for KMT-2022-BLG-1480L. It is estimated that the host and planet masses and the projected planet-host separation are $(M_{\mathrm{h}}/M_{\odot },M_{\mathrm{p}}/M_{\mathrm{U}},a_{\perp }/\mathrm{au})=(0.43_{-0.23}^{+0.35},1.73_{-0.92}^{+1.42},2.03_{-0.38}^{+0.25})$ for KMT-2022-BLG-0475L, and $(0.18_{-0.09}^{+0.16},1.82_{-0.92}^{+1.60},1.22_{-0.14}^{+0.15})$ for KMT-2022-BLG-1480L, where $M_{\mathrm{U}}$ denotes the mass of Uranus. Both planetary systems share common characteristics that the primaries of the lenses are early-mid M dwarfs lying in the Galactic bulge and the companions are ice giants lying beyond the snow lines of the planetary systems.

10 pages, 10 figures