{
  "id": "2205.12584",
  "version": "v1",
  "published": "2022-05-25T08:57:06.000Z",
  "updated": "2022-05-25T08:57:06.000Z",
  "title": "KMT-2021-BLG-0171Lb and KMT-2021-BLG-1689Lb: Two Microlensing Planets in the KMTNet High-cadence Fields with Followup Observations",
  "authors": [
    "Hongjing Yang",
    "Weicheng Zang",
    "Andrew Gould",
    "Jennifer C. Yee",
    "Kyu-Ha Hwang",
    "Grant Christie",
    "Takahiro Sumi",
    "Jiyuan Zhang",
    "Shude Mao",
    "Michael D. Albrow",
    "Sun-Ju Chung",
    "Cheongho Han",
    "Youn Kil Jung",
    "Yoon-Hyun Ryu",
    "In-Gu Shin",
    "Yossi Shvartzvald",
    "Sang-Mok Cha",
    "Dong-Jin Kim",
    "Hyoun-Woo Kim",
    "Seung-Lee Kim",
    "Chung-Uk Lee",
    "Dong-Joo Lee",
    "Yongseok Lee",
    "Byeong-Gon Park",
    "Richard W. Pogge",
    "John Drummond",
    "Dan Maoz",
    "Jennie McCormick",
    "Tim Natusch",
    "Matthew T. Penny",
    "Wei Zhu",
    "Ian A. Bond",
    "Fumio Abe",
    "Richard Barry",
    "David P. Bennett",
    "Aparna Bhattacharya",
    "Martin Donachie",
    "Hirosane Fujii",
    "Akihiko Fukui",
    "Yuki Hirao",
    "Yoshitaka Itow",
    "Rintaro Kirikawa",
    "Iona Kondo",
    "Naoki Koshimoto",
    "Man Cheung Alex Li",
    "Yutaka Matsubara",
    "Yasushi Muraki",
    "Shota Miyazaki",
    "Greg Olmschenk",
    "Clément Ranc",
    "Nicholas J. Rattenbury",
    "Yuki Satoh",
    "Hikaru Shoji",
    "Stela Ishitani Silva",
    "Daisuke Suzuki",
    "Yuzuru Tanaka",
    "Paul J. Tristram",
    "Tsubasa Yamawaki",
    "Atsunori Yonehara"
  ],
  "comment": "18 pages, 15 figures, 10 tabels; submitted to MNRAS",
  "categories": [
    "astro-ph.EP",
    "astro-ph.GA",
    "astro-ph.IM"
  ],
  "abstract": "Follow-up observations of high-magnification gravitational microlensing events can fully exploit their intrinsic sensitivity to detect extrasolar planets, especially those with small mass ratios. To make followup more uniform and efficient, we develop a system, HighMagFinder, based on the real-time data from the Korean Microlensing Telescope Network (KMTNet) to automatically alert possible ongoing high-magnification events. We started a new phase of follow-up observations with the help of HighMagFinder in 2021. Here we report the discovery of two planets in high-magnification microlensing events, KMT-2021-BLG-0171 and KMT-2021-BLG-1689, which were identified by the HighMagFinder. We find that both events suffer the ``central-resonant'' caustic degeneracy. The planet-host mass-ratio is $q\\sim4.7\\times10^{-5}$ or $q\\sim 2.2\\times10^{-5}$ for KMT-2021-BLG-0171, and $q\\sim2.5\\times10^{-4}$ or $q\\sim 1.8\\times10^{-4}$ for KMT-2021-BLG-1689. Together with two events reported by Ryu et al. (2022), four cases that suffer such degeneracy have been discovered in the 2021 season alone, indicating that the degenerate solutions may have been missed in some previous studies. We also propose a new factor for weighting the probability of each solution from the phase-space. The resonant interpretations for the two events are disfavored under this consideration. This factor can be included in future statistical studies to weight degenerate solutions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-05-25T08:57:06.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "kmtnet high-cadence fields",
      "followup observations",
      "microlensing planets",
      "follow-up observations",
      "korean microlensing telescope network"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 18,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}