Revealing the Planet Mass Function beyond the Snow Line

• Project/Area Number: 19KK0082
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 16:Astronomy and related fields
• Research Institution: Osaka University (2020-2023); Japan Aerospace EXploration Agency (2019)
• Principal Investigator: 鈴木 大介 大阪大学, 大学院理学研究科, 助教 (60807717)
• Co-Investigator(Kenkyū-buntansha): 福井 暁彦 東京大学, 大学院総合文化研究科, 特任助教 (60632049) ; 阿部 文雄 名古屋大学, 宇宙地球環境研究所, 客員准教授 (80184224)
• Project Period (FY): 2019-10-07 – 2025-03-31
• Project Status: Granted (Fiscal Year 2023)
• Budget Amount: ¥18,330,000 (Direct Cost: ¥14,100,000、Indirect Cost: ¥4,230,000); Fiscal Year 2024: ¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000); Fiscal Year 2023: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2022: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000); Fiscal Year 2021: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000); Fiscal Year 2020: ¥3,510,000 (Direct Cost: ¥2,700,000、Indirect Cost: ¥810,000); Fiscal Year 2019: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 系外惑星 / 光赤外線天文学 / 重力マイクロレンズ / 太陽系外惑星 / 惑星形成

Outline of Research at the Start

重力マイクロレンズ法による太陽系外惑星探査は、氷境界外側において地球質量まで探査可能な唯一の手法である。しかし、従来は主星・惑星の質量の絶対値を決めることが困難だった。本研究では、海外の研究者と協力し、MOA-IIなどの従来からのマイクロレンズ観測に加え、大口径望遠鏡の補償光学系を用いて主星を直接観測することで、質量の絶対値を決定する。これにより、氷境界外側の冷たい惑星の質量分布及び、その主星質量依存性を初めて明らかにする。本研究により、他の系外惑星探査手法を用いた氷境界内側の観測統計結果や惑星形成理論モデルとの直接比較が可能となり、惑星形成過程の理解が大幅に進む。

Outline of Annual Research Achievements

本研究では、ニュージーランドのMOA-II望遠鏡を用いたマイクロレンズ系外惑星探査を実施し、合計約12個の惑星を含む高増光イベントを検出する。それらをPRIMEなどの近赤外線望遠鏡で追加観測することで近赤外線での光度曲線を取得し、従来の可視光観測だけでなく近赤外線においてもソース天体の明るさを測定することが重要な点である。2023年度よりPRIME望遠鏡で観測可能となったが、検出器の半分が読み出し回路の不具合により使用できず、23年6月に米国共同研究者らとPRIME-Camのメンテナンスを行なった。全ての検出器で画像取得が可能となり23年度後半はMOAとの同時観測が期待された。しかし、カメラ内部において想定よりも温度が高く、検出器温度をノミナル値まで下げることができず、暗電流値が高いままでの観測となった。非線形な振る舞いをする暗電流値を含む画像処理ソフトウェアの開発は非常に困難であったが、1次処理までできるようになった。

また、ソース天体のレンズ天体を分離するための高空間分解撮像データとして、Keck望遠鏡で取得した画像解析をするためのソフトウェア開発を進め、あるイベントに対してレンズ-ソースの分離及び、レンズ天体のフラックス測定に成功した。

さらに、銀河系モデルを用いた統計解析により、主星質量に対する惑星頻度の依存性についての研究を進めた。

Current Status of Research Progress

3: Progress in research has been slightly delayed.

Reason

COVID-19の影響によりPRIMEのファーストライトは当初の予定より遅れた。また、検出器読み出し回路の不具合への対処や、想定よりも高い検出器温度での運用による非線形な暗電流値への対処等で時間がかかり、PRIMEでの定常観測開始は当初の予定より3年ほど遅れている。しかし、非線形な暗電流値を含む画像処理ソフトウェアの開発で得られた知見は、今後の様々な赤外線観測装置で役立つ可能性がある。
MOA-IIで検出されたマイクロレンズイベントの光度曲線に、異なる測光ソフトウェアが使われていることがわかり、イベント検出効率の解析をやり直す必要がある。再解析に時間を要しているが、一方で、銀河系モデルと先行研究の惑星サンプルを用いる統計解析手法を確立した。当初予定していなかった新たな解析手法を用いた結果が得られたが、やや遅れているとした。

Strategy for Future Research Activity

当初の予定より遅れているが、24年度以降はPRIMEのデータが取得できる。PRIMEの画像からマイクロレンズイベントを検出し、可視光のデータと含めてイベント解析を進める。
一方で、23年度後半からは、マウントジョン天文台での様々な問題で、MOA-II望遠鏡は運用を停止している。24年度半ばから観測が再開できる見込みである。Keckの画像解析も引き続き進める。

Research Products

• [Int'l Joint Research] マッセー大学/オークランド大学/カンタベリー大学(ニュージーランド)
• [Int'l Joint Research] NASA / GSFC(米国)
• [Journal Article] Three sub-Jovian-mass microlensing planets: MOA-2022-BLG-563Lb, KMT-2023-BLG-0469Lb, and KMT-2023-BLG-0735Lb (2024)
  • Author(s): Han Cheongho、Jung Youn Kil、Bond Ian A.、et al.
  • Journal Title: Astronomy & Astrophysics Volume: 683 Pages: A115-A115
  • DOI: 10.1051/0004-6361/202347951
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2014-BLG-0221Lb: A Jupiter Mass Ratio Companion Orbiting Either a Late-type Star or a Stellar Remnant (2024)
  • Author(s): Kirikawa Rintaro、Sumi Takahiro、Bennett David P.、et al.
  • Journal Title: The Astronomical Journal Volume: 167 Issue: 4 Pages: 154-154
  • DOI: 10.3847/1538-3881/ad2703
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MOA-2020-BLG-208Lb: Cool Sub-Saturn-mass Planet within Predicted Desert (2023)
  • Author(s): Olmschenk G. et al. (including Fukui A.)
  • Journal Title: The Astronomical Journal Volume: 165 Issue: 4 Pages: 175-175
  • DOI: 10.3847/1538-3881/acbcc8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Kepler K2 Campaign 9 - II. First space-based discovery of an exoplanet using microlensing (2023)
  • Author(s): Specht D. et al. (including Fukui A.)
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 520 Issue: 4 Pages: 6350-6366
  • DOI: 10.1093/mnras/stad212
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MOA-2022-BLG-249Lb: Nearby microlensing super-Earth planet detected from high-cadence surveys (2023)
  • Author(s): Han Cheongho、Gould Andrew、Jung Youn Kil、et al.
  • Journal Title: Astronomy & Astrophysics Volume: 674 Pages: A89-A89
  • DOI: 10.1051/0004-6361/202346166
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Prediction of Planet Yields by the PRime-focus Infrared Microlensing Experiment Microlensing Survey (2023)
  • Author(s): Kondo Iona、Sumi Takahiro、Koshimoto Naoki、Rattenbury Nicholas J.、Suzuki Daisuke、Bennett David P.
  • Journal Title: The Astronomical Journal Volume: 165 Issue: 6 Pages: 254-254
  • DOI: 10.3847/1538-3881/acccf9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-1150Lb: Microlensing planet detected through a densely covered planetary-caustic signal (2023)
  • Author(s): Han Cheongho、Jung Youn Kil、Bond Ian A.、et al.
  • Journal Title: Astronomy & Astrophysics Volume: 675 Pages: A36-A36
  • DOI: 10.1051/0004-6361/202346596
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Probable brown dwarf companions detected in binary microlensing events during the 2018?2020 seasons of the KMTNet survey (2023)
  • Author(s): Han Cheongho、Kil Jung Youn、Kim Doeon、et al.
  • Journal Title: Astronomy & Astrophysics Volume: 675 Pages: A71-A71
  • DOI: 10.1051/0004-6361/202245455
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2022-BLG-0440Lb: A new <i>q</i> &amp;lt; 10?4 microlensing planet with the central-resonant caustic degeneracy broken (2023)
  • Author(s): Zhang Jiyuan、Zang Weicheng、Jung Youn Kil、et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 522 Issue: 4 Pages: 6055-6069
  • DOI: 10.1093/mnras/stad1398
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2022-BLG-0475Lb and KMT-2022-BLG-1480Lb: Microlensing ice giants detected via the non-caustic-crossing channel (2023)
  • Author(s): Han Cheongho、Lee Chung-Uk、Bond Ian A.、et al.
  • Journal Title: Astronomy &amp; Astrophysics Volume: 676 Pages: A97-A97
  • DOI: 10.1051/0004-6361/202346667
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Systematic KMTNet Planetary Anomaly Search. IX. Complete Sample of 2016 Prime-field Planets (2023)
  • Author(s): Shin In-Gu、Yee Jennifer C.、Zang Weicheng、et al.
  • Journal Title: The Astronomical Journal Volume: 166 Issue: 3 Pages: 104-104
  • DOI: 10.3847/1538-3881/ace96d
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Terrestrial- and Neptune-mass Free-Floating Planet Candidates from the MOA-II 9 yr Galactic Bulge Survey (2023)
  • Author(s): Koshimoto Naoki、Sumi Takahiro、Bennett David P.、et al.
  • Journal Title: The Astronomical Journal Volume: 166 Issue: 3 Pages: 107-107
  • DOI: 10.3847/1538-3881/ace689
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Free-floating Planet Mass Function from MOA-II 9 yr Survey toward the Galactic Bulge (2023)
  • Author(s): Sumi Takahiro、Koshimoto Naoki、Bennett David P.、et al.
  • Journal Title: The Astronomical Journal Volume: 166 Issue: 3 Pages: 108-108
  • DOI: 10.3847/1538-3881/ace688
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2019-BLG-0825: Constraints on the Source System and Effect on Binary-lens Parameters Arising from a Five-day Xallarap Effect in a Candidate Planetary Microlensing Event (2023)
  • Author(s): Satoh Yuki K.、Koshimoto Naoki、Bennett David P.、et al.
  • Journal Title: The Astronomical Journal Volume: 166 Issue: 3 Pages: 116-116
  • DOI: 10.3847/1538-3881/ace908
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-1547Lb: Giant microlensing planet detected through a signal deformed due to source binarity (2023)
  • Author(s): Han Cheongho、Zang Weicheng、Jung Youn Kil、et al.
  • Journal Title: Astronomy &amp; Astrophysics Volume: 678 Pages: A101-A101
  • DOI: 10.1051/0004-6361/202347366
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Brown dwarf companions in binaries detected in the 2021 season high-cadence microlensing surveys (2023)
  • Author(s): Han Cheongho、Jung Youn Kil、Bond Ian A.、et al.
  • Journal Title: Astronomy &amp; Astrophysics Volume: 678 Pages: A190-A190
  • DOI: 10.1051/0004-6361/202347014
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Systematic reanalysis of KMTNet microlensing events, paper I: Updates of the photometry pipeline and a new planet candidate (2023)
  • Author(s): Yang Hongjing、Yee Jennifer C、Hwang Kyu-Ha、et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 528 Issue: 1 Pages: 11-27
  • DOI: 10.1093/mnras/stad3672
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Mass Production of 2021 KMTNet Microlensing Planets. III. Analysis of Three Giant Planets (2023)
  • Author(s): Shin, In-Gu; Yee, Jennifer C.; Gould, Andrew and Suzuki, Daisuke et al.
  • Journal Title: The Astronomical Journal Volume: 165 Issue: 1 Pages: 8-8
  • DOI: 10.3847/1538-3881/ac9d93
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Brown dwarf companions in microlensing binaries detected during the 2016-2018 seasons (2022)
  • Author(s): Han, Cheongho; Ryu, Yoon-Hyun; Shin, In-Gu and Suzuki, Daisuke et al.
  • Journal Title: Astronomy & Astrophysics Volume: 667 Pages: A64-A64
  • DOI: 10.1051/0004-6361/202244186
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-0171Lb and KMT-2021-BLG-1689Lb: two microlensing planets in the KMTNet high-cadence fields with followup observations (2022)
  • Author(s): Yang, Hongjing; Zang, Weicheng; Gould, Andrew and Suzuki, Daisuke et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 516 Issue: 2 Pages: 1894-1909
  • DOI: 10.1093/mnras/stac2023
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MOA-2020-BLG-135Lb: A New Neptune-class Planet for the Extended MOA-II Exoplanet Microlens Statistical Analysis (2022)
  • Author(s): Ishitani Silva, Stela; Ranc, Clement; Bennett, David P. and Suzuki, Daisuke et al.
  • Journal Title: The Astronomical Journal Volume: 164 Issue: 3 Pages: 118-118
  • DOI: 10.3847/1538-3881/ac82b8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MOA-2019-BLG-008Lb: A New Microlensing Detection of an Object at the Planet/Brown Dwarf Boundary (2022)
  • Author(s): Bechelet, E.; Tsapras, Y. ; Gould, Andrew; Suzuki, Daisuke et al.
  • Journal Title: The Astronomical Journal Volume: 164 Issue: 3 Pages: 75-75
  • DOI: 10.3847/1538-3881/ac78ed
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2018-BLG-0799Lb: a q ~ 2.7 × 10^-3 planet with Spitzer parallax (2022)
  • Author(s): Zang, Weicheng; Shvartzvald, Yossi; Udalski, Andrzej and Suzuki, Daisuke et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 514 Issue: 4 Pages: 5952-5968
  • DOI: 10.1093/mnras/stac1631
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Asteroid Lightcurves from the MOA-II Survey: A pilot study (2022)
  • Author(s): Cordwell A J., et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 674 Issue: 2 Pages: 1-1
  • DOI: 10.1093/mnras/stac674
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Four sub-Jovian-mass planets detected by high-cadence microlensing surveys (2022)
  • Author(s): Han, Cheongho; Kim, Doeon; Gould, Andrew and Suzuki, Daisuke et al.
  • Journal Title: Astronomy & Astrophysics Volume: 664 Pages: A33-A33
  • DOI: 10.1051/0004-6361/202243484
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Systematic KMTNet planetary anomaly search. V. Complete sample of 2018 prime-field (2022)
  • Author(s): Gould, Andrew; Han, Cheongho; Zang, Weicheng and Suzuki Daisuke et al.
  • Journal Title: Astronomy & Astrophysics Volume: 664 Pages: A13-A13
  • DOI: 10.1051/0004-6361/202243744
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An Isolated Mass-gap Black Hole or Neutron Star Detected with Astrometric Microlensing (2022)
  • Author(s): Lam, Casey; Y. Lu, Jessica R.; Udalski, Andrzej and Suzuki, Daisuke et al.
  • Journal Title: The Astrophysical Journal Letters Volume: 933 Issue: 1 Pages: L23-L23
  • DOI: 10.3847/2041-8213/ac7442
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An Isolated Stellar-mass Black Hole Detected through Astrometric Microlensing (2022)
  • Author(s): Sahu, Kailash C.; Anderson, Jay; Casertano, Stefano and Suzuki, Daisuke et al.
  • Journal Title: The Astrophysical Journal Volume: 933 Issue: 1 Pages: 83-83
  • DOI: 10.3847/1538-4357/ac739e
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Precision measurement of a brown dwarf mass in a binary system in the microlensing event. OGLE-2019-BLG-0033/MOA-2019-BLG-035 (2022)
  • Author(s): Herald, A. ; Udalski, A. ; Bozza, V. and Suzuki, D. et al.
  • Journal Title: Astronomy & Astrophysics Volume: 663 Pages: A100-A100
  • DOI: 10.1051/0004-6361/202243490
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2016-BLG-1093Lb: A Sub-Jupiter-mass Spitzer Planet Located in the Galactic Bulge (2022)
  • Author(s): Shin, In-Gu; Yee, Jennifer C.; Hwang, Kyu-Ha and Suzuki, Daisuke et al.
  • Journal Title: The Astronomical Journal Volume: 163 Issue: 6 Pages: 254-254
  • DOI: 10.3847/1538-3881/ac6513
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-1077L: The fifth confirmed multiplanetary system detected by microlensing (2022)
  • Author(s): Han, Cheongho; Gould, Andrew; Bond, Ian A. and Suzuki, Daisuke et al.
  • Journal Title: Astronomy & Astrophysics Volume: 662 Pages: A70-A70
  • DOI: 10.1051/0004-6361/202243550
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2014-BLG-0319: A Sub-Jupiter-mass Planetary Event Encountered Degeneracy with Different Mass Ratios and Lens-source Relative Proper Motions (2022)
  • Author(s): Miyazaki Shota, et al.
  • Journal Title: The Astronomical Journal Volume: 163 Issue: 3 Pages: 123-123
  • DOI: 10.3847/1538-3881/ac4960
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Systematic KMTNet Planetary Anomaly Search. II. Six New q &lt; 2 × 10^?4 Mass-ratio Planets (2022)
  • Author(s): Hwang Kyu-Ha, et al.
  • Journal Title: The Astronomical Journal Volume: 163 Issue: 2 Pages: 43-43
  • DOI: 10.3847/1538-3881/ac38ad
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-0912Lb: a microlensing super Earth around a K-type star (2022)
  • Author(s): Han Cheongho, et al.
  • Journal Title: Astronomy &amp; Astrophysics Volume: 658 Pages: A94-A94
  • DOI: 10.1051/0004-6361/202142495
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An Earth-mass planet in a time of COVID-19: KMT-2020-BLG-0414Lb (2021)
  • Author(s): Zang Weicheng, et al.
  • Journal Title: Research in Astronomy and Astrophysics Volume: 21 Issue: 9 Pages: 239-239
  • DOI: 10.1088/1674-4527/21/9/239
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2019-BLG-0960 Lb: the Smallest Microlensing Planet (2021)
  • Author(s): Yee Jennifer C., et al.
  • Journal Title: The Astronomical Journal Volume: 162 Issue: 5 Pages: 180-180
  • DOI: 10.3847/1538-3881/ac1582
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2021-BLG-0322: Severe degeneracy between triple-lens and higher-order binary-lens interpretations (2021)
  • Author(s): Han Cheongho, et al.
  • Journal Title: Astronomy &amp; Astrophysics Volume: 655 Pages: A24-A24
  • DOI: 10.1051/0004-6361/202141939
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Systematic KMTNet Planetary Anomaly Search. I. OGLE-2019-BLG-1053Lb, a Buried Terrestrial Planet (2021)
  • Author(s): Zang Weicheng, et al.
  • Journal Title: The Astronomical Journal Volume: 162 Issue: 4 Pages: 163-163
  • DOI: 10.3847/1538-3881/ac12d4
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] New giant planet beyond the snow line for an extended MOA exoplanet microlens sample (2021)
  • Author(s): Ranc Clement, et al.
  • Journal Title: Monthly Notices of the Royal Astronomical Society Volume: 506 Issue: 1 Pages: 1498-1506
  • DOI: 10.1093/mnras/stab1787
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] No Large Dependence of Planet Frequency on Galactocentric Distance (2021)
  • Author(s): Koshimoto, Naoki; Bennett, David P. ; Suzuki, Daisuke; Bond, Ian A.
  • Journal Title: The Astrophysical Journal Letters Volume: 918, Issue 1, id.L8 Issue: 1 Pages: L8-L8
  • DOI: 10.3847/2041-8213/ac17ec
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] OGLE-2018-BLG-1185b: A Low-mass Microlensing Planet Orbiting a Low-mass Dwarf (2021)
  • Author(s): Kondo Iona et al.
  • Journal Title: The Astronomical Journal Volume: 162 Issue: 2 Pages: 77-77
  • DOI: 10.3847/1538-3881/ac00ba
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] MOA-2006-BLG-074: Recognizing Xallarap Contaminants in Planetary Microlensing (2021)
  • Author(s): Rota P. et al.
  • Journal Title: The Astronomical Journal Volume: 162 Issue: 2 Pages: 59-59
  • DOI: 10.3847/1538-3881/ac0155
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2019-BLG-0371 and the Limits of Bayesian Analysis (2021)
  • Author(s): Kim Yun Hak, et al.
  • Journal Title: The Astronomical Journal Volume: 162 Issue: 1 Pages: 17-17
  • DOI: 10.3847/1538-3881/abf930
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2019-BLG-1715: Planetary Microlensing Event with Three Lens Masses and Two Source Stars (2021)
  • Author(s): Han Cheongho, et al.
  • Journal Title: The Astronomical Journal Volume: 161 Issue: 6 Pages: 270-270
  • DOI: 10.3847/1538-3881/abf4d0
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] J-GEM optical and near-infrared follow-up of gravitational wave events during LIGO’s and Virgo’s third observing run (2021)
  • Author(s): Sasada Mahito et al.
  • Journal Title: Progress of Theoretical and Experimental Physics Volume: 007 Issue: 5 Pages: 1-25
  • DOI: 10.1093/ptep/ptab007
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Wide-orbit Exoplanet OGLE-2012-BLG-0838Lb (2020)
  • Author(s): Poleski R.、Suzuki Daisuke、et al.
  • Journal Title: The Astronomical Journal Volume: 159 Issue: 6 Pages: 261-261
  • DOI: 10.3847/1538-3881/ab8a49
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Bayesian Approach for Determining Microlens System Properties with High-angular-resolution Follow-up Imaging (2020)
  • Author(s): Koshimoto Naoki、Bennett David P.、Suzuki Daisuke
  • Journal Title: The Astronomical Journal Volume: 159 Issue: 6 Pages: 268-268
  • DOI: 10.3847/1538-3881/ab8adf
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] One Planet or Two Planets? The Ultra-sensitive Extreme-magnification Microlensing Event KMT-2019-BLG-1953 (2020)
  • Author(s): Han Cheongho、Kim Doeon、Jung Youn Kil、et al.
  • Journal Title: The Astronomical Journal Volume: 160 Issue: 1 Pages: 17-17
  • DOI: 10.3847/1538-3881/ab91ac
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] A Gas Giant Planet in the OGLE-2006-BLG-284L Stellar Binary System (2020)
  • Author(s): Bennett David P.、Udalski Andrzej、Bond Ian A. et al.
  • Journal Title: The Astronomical Journal Volume: 160 Issue: 2 Pages: 72-72
  • DOI: 10.3847/1538-3881/ab9cb9
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2017-BLG-0406: Spitzer Microlens Parallax Reveals Saturn-mass Planet Orbiting M-dwarf Host in the Inner Galactic Disk (2020)
  • Author(s): Hirao Yuki、Bennett David P.、Ryu Yoon-Hyun、 et al.
  • Journal Title: The Astronomical Journal Volume: 160 Issue: 2 Pages: 74-74
  • DOI: 10.3847/1538-3881/ab9ac3
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] OGLE-2018-BLG-1269Lb: A Jovian Planet with a Bright I = 16 Host (2020)
  • Author(s): Jung Youn Kil、Gould Andrew、Udalski Andrzej, et al.
  • Journal Title: The Astronomical Journal Volume: 160 Issue: 3 Pages: 148-148
  • DOI: 10.3847/1538-3881/abacc8
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] KMT-2019-BLG-0842Lb: A Cold Planet below the Uranus/Sun Mass Ratio (2020)
  • Author(s): Jung Youn Kil、Udalski Andrzej、Zang Weicheng、et al.
  • Journal Title: The Astronomical Journal Volume: 160 Issue: 6 Pages: 255-255
  • DOI: 10.3847/1538-3881/abbe93
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Dependence of Planet Frequency on Star Mass and Galactic Distance (2024)
  • Author(s): Kansuke Nunota
  • Organizer: 26th International Microlensing Conference
  • Int'l Joint Research
• [Presentation] Status of the PRIME Near-Infrared Microlensing Survey: First year (2024)
  • Author(s): Naoki Koshimoto
  • Organizer: 26th International Microlensing Conference
  • Int'l Joint Research
• [Presentation] すばる望遠鏡HSCを用いた銀河系中心方向のダスト減光の研究(2) (2023)
  • Author(s): 鈴木大介
  • Organizer: 日本天文学会2023年秋季年会
• [Presentation] PRIME 望遠鏡の近赤外線検出器 (H4RG-10) の非線形性補正 (2023)
  • Author(s): 濱田龍星
  • Organizer: 日本天文学会2023年秋季年会
• [Presentation] Extinction study toward the inner milky way with Subaru HSC (2022)
  • Author(s): Daisuke Suzuki
  • Organizer: The dawn of astrometric microlensing From cold exoplanets to black-holes
  • Int'l Joint Research
• [Presentation] OGLE-2019-BLG-0825 ; Identified Xallarap Effect of ~5.5 days Affects Binary-lens Parameters in Planetary Candidate Microlensing Event (2022)
  • Author(s): Yuki Satoh
  • Organizer: The dawn of astrometric microlensing From cold exoplanets to black-holes
  • Int'l Joint Research
• [Presentation] Cold Planet Demographics from 12 yrs MOA-II Microlensing Survey Data (2020)
  • Author(s): Daisuke Suzuki
  • Organizer: EXOPLANET DEMOGRAPHICS
  • Int'l Joint Research
• [Presentation] すばる望遠鏡Hyper Suprime-Camを用いた銀河系中心方向のダスト減光の研究 (2020)
  • Author(s): 鈴木大介
  • Organizer: 日本天文学会2020年春季年会
• [Remarks] 遠い軌道を回る冷たい系外惑星が銀河系内の広い範囲で存在することを解明
  • URL: https://resou.osaka-u.ac.jp/ja/research/2021/20210827_2