Systematic KMTNet Planetary Anomaly Search. II. Six New q < 2 × 10<sup>−4</sup> Mass-ratio Planets
Kyu‐Ha Hwang, Weicheng Zang, Andrew Gould, A. Udalski, I. A. Bond, Hongjing Yang, Shude Mao, (Lead Authors), Michael D. Albrow, Sun‐Ju Chung, Cheongho Han, Youn Kil Jung, Yoon-Hyun Ryu, In-Gu Shin, Yossi Shvartzvald, Jennifer C. Yee, 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, P. Mróz, Radek Poleski, J. Skowron, M. K. Szymański, I. Soszyński, P. Pietrukowicz, S. Kozłowski, K. Ulaczyk, Krzysztof A. Rybicki, Patryk Iwanek, Marcin Wrona, M. Gromadzki, Fumio Abe, Richard Barry, D. P. Bennett, Aparna Bhattacharya, Hirosame Fujii, Akihiko Fukui, Yuki Hirao, Y. Itow, Rintaro Kirikawa, Iona Kondo, Naoki Koshimoto, Brandon Munford, Y. Matsubara, Shota Miyazaki, Y. Muraki, Greg Olmschenk, Clément Ranc, Nicholas J. Rattenbury, Yuki Satoh, Hikaru Shoji, Stela Ishitani Silva, T. Sumi, Daisuke Suzuki, P. J. Tristram, Atsunori Yonehara, Xiangyu Zhang, Wei Zhu, Matthew T. Penny, P. Fouqué, (The Tsinghua & CFHT Microlensing Group)
Abstract
Abstract We apply the automated AnomalyFinder algorithm of Paper I to 2018–2019 light curves from the ≃13 deg 2 covered by the six KMTNet prime fields, with cadences Γ ≥ 2 hr −1 . We find a total of 11 planets with mass ratios q < 2 × 10 −4 , including 6 newly discovered planets, 1 planet that was reported in Paper I, and recovery of 4 previously discovered planets. One of the new planets, OGLE-2018-BLG-0977Lb, is in a planetary caustic event, while the other five (OGLE-2018-BLG-0506Lb, OGLE-2018-BLG-0516Lb, OGLE-2019-BLG-1492Lb, KMT-2019-BLG-0253, and KMT-2019-BLG-0953) are revealed by a “dip” in the light curve as the source crosses the host-planet axis on the opposite side of the planet. These subtle signals were missed in previous by-eye searches. The planet-host separations (scaled to the Einstein radius), s , and planet-host mass ratios, q , are, respectively, ( s , q × 10 5 ) = (0.88, 4.1), (0.96 ± 0.10, 8.3), (0.94 ± 0.07, 13), (0.97 ± 0.07, 18), (0.97 ± 0.04, 4.1), and (0.74, 18), where the “ ± ” indicates a discrete degeneracy. The 11 planets are spread out over the range <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>−</mml:mo> <mml:mn>5</mml:mn> <mml:mo><</mml:mo> <mml:mi>log</mml:mi> <mml:mi>q</mml:mi> <mml:mo><</mml:mo> <mml:mo>−</mml:mo> <mml:mn>3.7</mml:mn> </mml:math> . Together with the two planets previously reported with q ∼ 10 −5 from the 2018–2019 nonprime KMT fields, this result suggests that planets toward the bottom of this mass-ratio range may be more common than previously believed.