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#author("2025-07-09T15:25:01+00:00","default:wwwadm","wwwadm") #author("2025-08-12T00:26:08+00:00","default:wwwadm","wwwadm") * IoA Seminar 2025 / 令和7年度(2025年度) 東京大学天文学教育研究センター談話会 [#c9bc2851] #contents * 本談話会について [#c1b638ff] ** 趣旨 [#d48cd456] 東京大学・天文学教育研究センターでは2003年4月から談話会を開いています。 第一線で活躍されている研究者の方々を講師にお招きし、最先端の研究成果をお話しいただきます。 講師の方には、大学院生の参加者のことも考慮し、レビュー的な側面も含めた上で、ご自身の研究紹介をお願いしています。&br; なお、当談話会は天文学研究者・学生を対象に大学・大学院での 専門的な研究と教育を目的として開催されています。 一般の方は[[公開講座・講演会>https://www.u-tokyo.ac.jp/ja/society/visit-lectures/d04_01.html]]などにご参加いただければ幸いです。 **定例日時 [#ve668db6] - 木曜日 15:30-16:30 **場所 [#j9cedf34] - 天文センター講義室と zoom のハイブリッド開催を予定 **世話人（天文センター） [#q8bd3108] ML: semiadm _at_ ioa.s.u-tokyo.ac.jp please replace _at_ with @ - 2025年度 -- SAKON, Itsuki 左近 樹 isakon_at_ ioa.s.u-tokyo.ac.jp -- Kohno, Kotaro 河野孝太郎 kkohno_at_ioa.s.u-tokyo.ac.jp -- MOROKUMA, Kana 諸隈佳菜 kanamoro_at_ioa.s.u-tokyo.ac.jp **天文学教室談話会について [#ecc2eb80] - 天文学教室談話会については、[[こちら>http://www.astron.s.u-tokyo.ac.jp/seminar/seminar/]]をご覧ください。 * Upcoming Seminars [#ebd6a62d] --------------------------------------------------------- ** No. 430: July 24, 2025 (Thu) 15:30-16:30 [#dad05fe7] *** Place: Lecture Room, Institute of Astronomy, University of Tokyo / Zoom (hybrid) [#va7fc746] *** Speaker: Keiichi Ohnaka (Universidad Andrés Bello) [#d2a6b465] *** Title: Milliarcsecond-resolution near-infrared interferometric imaging of the rapidly changing red supergiant WOH G64 in the Large Magellanic Cloud [#cbd41df3] ** No. 431 (NAOJ談話会と共同開催): Aug 26, 2025 (Tue) 13:00-14:00 [#dad05fe7] *** Place: Large Seminar Room, Subaru Building, Mitaka/Tokyo Campus, NAOJ /Zoom (hybrid) [#va7fc746] *** Speaker: Gaspar Bakos (Princeton) [#d2a6b465] *** Title: Observing the Entire Visible Sky at High Precision with the HATPI Project [#kf065e92] Language: English Abstract: Intense mass loss at the red supergiant phase is crucial for better understanding the evolution of massive stars, particularly given that very early-phase spectra of supernovae (SNe) suggest significant increases in mass loss just before the SN explosion. WOH G64 is a rare, heavily dust-enshrouded red supergiant in the Large Magellanic Cloud (LMC) -- the brightest in the mid-IR in the LMC. We present milliarcsecond-resolution near-IR (2.0--2.45 micron) interferometric imaging of WOH G64 with the GRAVITY instrument at ESO's Very Large Telescope Interferometer (VLTI) -- the first close-up image of an individual star outside the Milky Way. The observed image reveals an elliptical ring-like structure and more compact, elongated inner emission with a size of ~4 x 2 mas. This elongated emission can be interpreted as a bipolar outflow or alternatively as a circumstellar envelope elongated due to a putative companion. Furthermore, based on our visible and near-IR photometric monitoring with the Rapid Eye Mount Telescope at La Silla since 2023 and the archival data, we found that a significant increase in the circumstellar dust should have started at some point between 2006 and 2016, perhaps due to episodic dust formation. Interestingly, another recent study reveals that the central star evolved from a red supergiant (3200 K) to a yellow hypergiant (4700 K) in 2014 within a year without an outburst or eruptive event. We will discuss ongoing and future observations to understand this unique object that provides a rare opportunity to witness the evolution of a massive star in real time and study the physics of the extreme mass loss. Abstract: Our team has recently commissioned the HATPI facility (www.hatpi.org) at Las Campanas Observatory in Chile. HATPI observes the entire visible sky 30 degrees above the horizon at moderately high spatial resolution, very high photometric precision, and with a fast cadence of 45 seconds. The instrument consists of 64 lenses, each equipped with a back illuminated CCD, and each lens unit capable of accurate micro-tracking. In brief, anything that happens in the night sky down to ~16th magnitude (at 45s cadence) or 18th magnitude (per night) is captured by HATPI. The scientific goal of HATPI is to observe the variable sky, while complementing LSST and TESS. In particular, the key science areas are i) transiting exoplanets and variable stars, ii) transient objects, such as gamma-ray burst afterglows iii) moving objects, such as near-earth asteroids and comets. I will summarize the exciting early science from the commissioning data of HATPI, and will eagerly await comments and suggestions. --------------------------------------------------------- * 今後の講演予定 [#ac94b97b] |BGCOLOR(cyan):#|BGCOLOR(cyan): Date|BGCOLOR(cyan):Speaker|BGCOLOR(cyan):Title|BGCOLOR(cyan):Chair| |430|2025年7月24日(木) 15:30-16:30 | Keiichi Ohnaka (Universidad Andrés Bello) | Milliarcsecond-resolution near-infrared interferometric imaging of the rapidly changing red supergiant WOH G64 in the Large Magellanic Cloud | I.Sakon | |431|2025年8月26日(火) 13:00-14:00 | Gaspar Bakos (Princeton) | Observing the Entire Visible Sky at High Precision with the HATPI Project | 国立天文台談話会と共同開催 | *終了した談話会(2025年度) [#h9b1f387] 詳細はこちら: [[令和7(2025)年度談話会]] |BGCOLOR(cyan):#|BGCOLOR(cyan): Date|BGCOLOR(cyan):Speaker|BGCOLOR(cyan):Title|BGCOLOR(cyan):Chair| |430|2025年7月24日(木) 15:30-16:30 | Keiichi Ohnaka (Universidad Andrés Bello) | Milliarcsecond-resolution near-infrared interferometric imaging of the rapidly changing red supergiant WOH G64 in the Large Magellanic Cloud | I.Sakon | |429|2025年4月17日(木) 15:30-16:30 | Eduardo Ibar (Universidad de Valparaíso) | The properties of emitting line galaxies discovered by the JWST Emission Line Survey (JELS) | I.Sakon | --------------------------------------------------------- *これまでの談話会 [#e657f394] -[[令和7(2025)年度談話会]] -[[令和6(2024)年度談話会]] -[[令和5(2023)年度談話会]] -[[令和4(2022)年度談話会]]（天文学教育研究センター・天文学教室合同談話会） -[[令和3(2021)年度談話会]]（天文学教育研究センター・天文学教室合同談話会） -[[令和2(2020)年度談話会]] -[[平成31(2019)年度談話会]] -[[平成30 (2018) 年度談話会]] -[[平成29 (2017) 年度談話会]] -[[平成28 (2016) 年度談話会]] -[[平成27 (2015) 年度談話会]] -[[平成26 (2014) 年度談話会]] -[[平成25 (2013) 年度談話会]] -[[平成24 (2012) 年度談話会]] -[[平成23 (2011) 年度談話会]] -[[平成22 (2010) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H22.html]] -[[平成21 (2009) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H21.html]] -[[平成20 (2008) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H20.html]] -[[平成19 (2007) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H19.html]] -[[平成18 (2006) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H18.html]] -[[平成17 (2005) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H17.html]] -[[平成16 (2004) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H16.html]] -[[平成15 (2003) 年度談話会:http://www.ioa.s.u-tokyo.ac.jp/danwakai//past/danwakai_H15.html]]
