KMT-2023-BLG-1431Lb: A New q < 10‑4 Microlensing Planet from a Subtle Signature
Abstract
The current studies of microlensing planets are limited by small number statistics. Follow-up observations of high-magnification microlensing events can efficiently form a statistical planetary sample. Since 2020, the Korea Microlensing Telescope Network (KMTNet) and the Las Cumbres Observatory (LCO) global network have been conducting a follow-up program for high-magnification KMTNet events. Here, we report the detection and analysis of a microlensing planetary event, KMT-2023-BLG-1431, for which the subtle (0.05 mag) and short-lived (5 hr) planetary signature was characterized by the follow-up from KMTNet and LCO. A binary-lens single-source (2L1S) analysis reveals a planet/host mass ratio of q = (0.72 ± 0.07) × 10‑4, and the single-lens binary-source (1L2S) model is excluded by Δχ 2 = 80. A Bayesian analysis using a Galactic model yields estimates of the host star mass of , the planetary mass of , and the lens distance of kpc. The projected planet-host separation of au or au, subject to the close/wide degeneracy. We also find that without the follow-up data, the survey-only data cannot break the degeneracy of central/resonant caustics and the degeneracy of 2L1S/1L2S models, showing the importance of follow-up observations for current microlensing surveys.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- May 2024
- DOI:
- 10.1088/1538-3873/ad48b8
- arXiv:
- arXiv:2311.13097
- Bibcode:
- 2024PASP..136e4402B
- Keywords:
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- Gravitational microlensing;
- Gravitational microlensing exoplanet detection;
- 672;
- 2147;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- PASP submitted. arXiv admin note: text overlap with arXiv:2301.06779