Systematic reanalysis of KMTNet microlensing events, paper I: Updates of the photometry pipeline and a new planet candidate
Hongjing Yang, Jennifer C. Yee, Kyu‐Ha Hwang, Qiyue Qian, I. A. Bond, Andrew Gould, Zhecheng Hu, J. Zhang, Shude Mao, Wei Zhu, Michael D. Albrow, Sun‐Ju Chung, Seung‐Lee Kim, Byeong-Gon Park, Cheongho Han, Youn Kil Jung, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Sang-Mok Cha, Dong-Jin Kim, Hyoun-Woo Kim, Chung‐Uk Lee, Dong-Joo Lee, Yongseok Lee, Richard W. Pogge, Weicheng Zang, Fumio Abe, Richard Barry, D. P. Bennett, Aparna Bhattacharya, M. Donachie, Hirosane Fujii, Akihiko Fukui, Yuki Hirao, Y. Itow, Rintaro Kirikawa, Iona Kondo, Naoki Koshimoto, Stela Ishitani Silva, Man Cheung Alex Li, Y. Matsubara, Y. Muraki, Daisuke Suzuki, P. J. Tristram, Atsunori Yonehara, Clément Ranc, Shota Miyazaki, Greg Olmschenk, Nicholas J. Rattenbury, Yuki Satoh, Hikaru Shoji, T. Sumi, Yuzuru Tanaka, Tsubasa Yamawaki
Abstract
ABSTRACT In this work, we update and develop algorithms for KMTNet tender-love care (TLC) photometry in order to create a new, mostly automated, TLC pipeline. We then start a project to systematically apply the new TLC pipeline to the historic KMTNet microlensing events, and search for buried planetary signals. We report the discovery of such a planet candidate in the microlensing event MOA-2019-BLG-421/KMT-2019-BLG-2991. The anomalous signal can be explained by either a planet around the lens star or the orbital motion of the source star. For the planetary interpretation, despite many degenerate solutions, the planet is most likely to be a Jovian planet orbiting an M or K dwarf, which is a typical microlensing planet. The discovery proves that the project can indeed increase the sensitivity of historic events and find previously undiscovered signals.