# KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane

## TL;DR

This paper reports the discovery of a super-Jovian exoplanet via microlensing near the Galactic plane, demonstrating the potential for planetary searches in this region despite observational challenges.

## Contribution

First detection of a super-Jovian microlensing planet in the Galactic plane, showing that such searches are feasible with modest observational efforts.

## Key findings

- The planet has a mass of approximately 4.5 Jupiter masses.
- The host star is an F or G dwarf with about 1.5 solar masses.
- The system can be studied through follow-up observations immediately.

## Abstract

We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian $M_{\rm planet} = 4.5\pm 1.3\,M_J$ planet orbiting an F or G dwarf $M_{\rm host} = 1.5\pm 0.4\,M_\odot$, which lies physically within ${\cal O}(10\,\pc)$ of the Galactic plane. The source star is a heavily extincted $A_I\sim 5.2$ luminous giant that has the lowest Galactic latitude, $b=-0.28^\circ$, of any planetary microlensing event. The relatively blue blended light is almost certainly either the host or its binary companion, with the first explanation being substantially more likely. This blend dominates the light at $I$ band and completely dominates at $R$ and $V$ bands. Hence, the lens system can be probed by follow-up observations immediately, i.e., long before the lens system and the source separate due to their relative proper motion. The system is well characterized despite the low cadence $\Gamma=0.15$--$0.20\,{\rm hr^{-1}}$ of observations and short viewing windows near the end of the bulge season. This suggests that optical microlensing planet searches can be extended to the Galactic plane at relatively modest cost.