KMT-2017-BLG-0673Lb and KMT-2019-BLG-0414Lb: Two microlensing planets detected in peripheral fields of KMTNet survey
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 3.7−2.1+2.2 MJ, and it is orbiting a late K-type host star with a mass of 0.63−0.35+0.37 M⊙. Under the planetary interpretation of KMT-2010-BLG-0414L, a star with a mass of 0.74−0.38+0.43 M⊙ hosts a planet with a mass of ~3.2-3.6 MJ 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.
Astronomy and Astrophysics
- Pub Date:
- October 2022
- planets and satellites: detection;
- gravitational lensing: micro;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies
- 9 pages, 7 figures