Wu, ZDong, SYi, TLiu, ZEl-Badry, KGould, AWyrzykowski, LRybicki, KABachelet, EChristie, GWde Almeida, LMonard, LAGMcCormick, JNatusch, TZieliński, PChen, HHuang, YLiu, CMérand, AMróz, PShangguan, JUdalski, AWoillez, JZhang, HHambsch, FJMikołajczyk, PJGromadzki, MRatajczak, MKruszyńska, KIhanec, NPylypenko, USitek, MHowil, KZola, SMichniewicz, OZejmo, MLewis, FBronikowski, MPotter, SAndrzejewski, JMerc, JStreet, RFukui, AFiguera Jaimes, RBozza, VRota, PCassan, ADominik, MTsapras, YHundertmark, MWambsganss, JBąkowska, KSłowikowska, A2024-07-222024-07-222024-07-09Astronomical Journal, ISSN: 0004-6256 (Print); 1538-3881 (Online), American Astronomical Society, 168(2), 62-62. doi: 10.3847/1538-3881/ad52030004-62561538-3881http://hdl.handle.net/10292/17811We report discovering an exoplanet from following up a microlensing event alerted by Gaia. The event Gaia22dkv is toward a disk source rather than the traditional bulge microlensing fields. Our primary analysis yields a Jovian planet with M p = 0.59 − 0.05 + 0.15 M J at a projected orbital separation r ⊥ = 1.4 − 0.3 + 0.8 au, and the host is a ∼1.1 M ⊙ turnoff star at ∼1.3 kpc. At r ′ ≈ 14 , the host is far brighter than any previously discovered microlensing planet host, opening up the opportunity to test the microlensing model with radial velocity (RV) observations. RV data can be used to measure the planet’s orbital period and eccentricity, and they also enable searching for inner planets of the microlensing cold Jupiter, as expected from the “inner-outer correlation” inferred from Kepler and RV discoveries. Furthermore, we show that Gaia astrometric microlensing will not only allow precise measurements of its angular Einstein radius θ E but also directly measure the microlens parallax vector and unambiguously break a geometric light-curve degeneracy, leading to the definitive characterization of the lens system.http://creativecommons.org/licenses/by/4.0/5109 Space Sciences51 Physical Sciences0201 Astronomical and Space SciencesAstronomy & Astrophysics5101 Astronomical sciences5107 Particle and high energy physicsJournal ArticleOpenAccess10.3847/1538-3881/ad5203