Gaia22dkvLb: A Microlensing Planet Potentially Accessible to Radial-velocity Characterization
Author:
Wu ZexuanORCID, Dong SuboORCID, Yi TuanORCID, Liu Zhuokai, El-Badry KareemORCID, Gould Andrew, Wyrzykowski L.ORCID, Rybicki K. A., Bachelet EtienneORCID, Christie Grant W., de Almeida L.ORCID, Monard L. A. G., McCormick J., Natusch Tim, Zieliński P.ORCID, Chen Huiling, Huang YangORCID, Liu ChangORCID, Mérand A.ORCID, Mróz PrzemekORCID, Shangguan JinyiORCID, Udalski AndrzejORCID, Woillez J.ORCID, Zhang HuaweiORCID, Hambsch Franz-JosefORCID, Mikołajczyk P. J.ORCID, Gromadzki M.ORCID, Ratajczak M., Kruszyńska Katarzyna, Ihanec N., Pylypenko Uliana, Sitek M., Howil K., Zola StaszekORCID, Michniewicz Olga, Zejmo Michal, Lewis Fraser, Bronikowski Mateusz, Potter Stephen, Andrzejewski Jan, Merc JaroslavORCID, Street RachelORCID, Fukui AkihikoORCID, Figuera Jaimes R., Bozza V.ORCID, Rota P., Cassan A., Dominik M.ORCID, Tsapras Y.ORCID, Hundertmark M., Wambsganss J.ORCID, Bąkowska K., Słowikowska A.ORCID
Abstract
Abstract
We 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.
Publisher
American Astronomical Society
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