KMT-2017-BLG-0673Lb and KMT-2019-BLG-0414Lb: Two microlensing planets detected in peripheral fields of KMTNet survey

Abstract

Aims. We investigate the microlensing data collected during the 2017-2019 seasons in the peripheral Galactic bulge fields with the aim of finding planetary signals in microlensing light curves observed with relatively sparse coverage. Methods. We first sort out lensing events with weak short-term anomalies in the lensing light curves from the visual inspection of all non-prime-field events, and then test various interpretations of the anomalies. From this procedure, we find two previously unidentified candidate planetary lensing events KMT-2017-BLG-0673 and KMT-2019-BLG-0414. It is found that the planetary signal of KMT-2017-BLG-0673 was produced by the source crossing over a planet-induced caustic, but it was previously missed because of the sparse coverage of the signal. On the other hand, the possibly planetary signal of KMT-2019-BLG-0414 was generated without caustic crossing, and it was previously missed due to the weakness of the signal. We identify a unique planetary solution for KMT-2017-BLG-0673. However, for KMT-2019-BLG-0414, we identify two pairs of planetary solutions, for each of which there are two solutions caused by the close-wide degeneracy, and a slightly less favored binary-source solution, in which a single lens mass gravitationally magnified a rapidly orbiting binary source with a faint companion (xallarap). Results. From Bayesian analyses, it is estimated that the planet KMT-2017-BLG-0673Lb has a mass of 3.7 +2.2 −2.1 M J , and it is orbiting a late K-type host star with a mass of 0.63 +0.37 −0.35 M ⊙ . Under the planetary interpretation of KMT-2010-BLG-0414L, a star with a mass of 0.74 +0.43 −0.38 M ⊙ hosts a planet with a mass of ∼ 3.2-3.6 M J depending on the solution. We discuss the possible resolution of the planet-xallarap degeneracy of KMT-2019-BLG-0414 by future adaptive-optics observations on 30 m class telescopes. The detections of the planets indicate the need for thorough investigations of non-prime-field lensing events for the complete census of microlensing planet samples.

KMT-2021-BLG-2010Lb, KMT-2022-BLG-0371Lb, and KMT-2022-BLG-1013Lb: Three microlensing planets detected via partially covered signals

“…The observational cadence for the peripheral fields of the KMTNet survey is 4-20 times lower than the 0.25 hr cadence of the prime fields, and thus the coverage of a short-duration signal detected in these low-cadence fields can be incomplete. Examples are the planetary events KMT-2017-BLG-0673 and KMT-2019-BLG-0414 (Han et al 2022a). In addition, the coverage of signals detected in the early or late phase of a bulge season can also be incomplete: In the two-planet event OGLE-2019-BLG-0468 (Han et al 2022b), the target rises and sets close to twilight.…”