1月12日（火）13：30～15：00 太陽系小天体セミナー zoom
Jan 12 Tue Solar System Minor Body Seminar
1月13日（水）13：30～15：00 NAOJ Science Colloquium zoom
Jan 13 Wed
1月13日（水）15：00～16：00 ALMA-J seminar zoom
Jan 13 Wed
詳細は以下をご覧下さい。
1月12日（火）
- キャンパス
- 三鷹
- セミナー名
- 太陽系小天体セミナー
- 定例・臨時の別
- 定例
- 日時
- 1月12日（火曜日）13時30分～15時
- 場所
- zoom
- 連絡先
- 名前：渡部潤一
- 備考
- テレビ会議またはスカイプによる参加も可
1月13日（水）
- Campus
- Mitaka
- Seminar
- NAOJ Science Colloquium
- Regularly Scheduled/Sporadic
- Every Wednesday
- Date
- 2021 January 13
- Time
- 13:30-15:00
- Place
- Zoom
- Speaker
- Haruka Hoshino (U. of Tokyo)
- Title
- Stellar mass dependence of the planetary system formed by giant impact
- Abstract
- Recently, much attention has been paid to planet formation in stars that are lighter than the Sun, especially M-type stars. So far, many so-called super-Earths, which are about ten times the mass of the Earth, have been discovered. These planets have been found relatively close to the central star, about 0.01-0.5 AU, and are known to be very compact in the case of multiple-planet systems. This feature is not found in terrestrial planets in the solar system, which is also a multiple-planet system. Besides, low-mass stars such as M-type stars have a habitable zone close to the star where liquid water can exist on the surface, so there is a high probability that terrestrial planets will be found within the habitable zone. However, until now, there have been few systematic studies on the effect of the mass of the central star on the planetary system. In particular, the orbital structure of the planetary system has not been investigated much. Therefore, we have been investigating the dependence of the orbital structure of planets on the central star mass. In our previous research, we confirmed that the orbital structure of planets becomes more unstable when the central star mass is small, and more collisions occur. However, the disk model was not sufficient, so we improved it this time. We have developed a new disk model according to the MMEN model and studied the process of giant impact of protoplanets in N-body simulations.
- Facilitator
- -Name：Akimasa Kataoka
1月13日(水）
- Campus
- Mitaka
- Seminar
- ALMA-J seminar
- Regularly Scheduled/Sporadic
- Every Wednesday
- Date and time
- 2021 Jan 13 15:00-16:00
- Place
- Zoom
- Speaker
- Ryo Kandori
- Affiliation
- Astrobiology Center of NINS
- Title
- Near Infrared Polarimetry of Molecular Cloud Cores with SIRPOL
- Abstract
-
I present a study of the magnetic field structure of molecular cloud cores based on the wide-field near-infrared polarimetry of background stars with IRSF/SIRPOL.
After the discovery of hourglass-shaped magnetic fields in a starless core in 2017, the number of reports of distorted core’s magnetic fields increases. The three dimensional analysis of hourglass fields makes it possible to estimate the line-of-sight inclination angle of the core’s magnetic axis for the first time. This leads to an accurate assessment of the kinematical stability of cores, including the effects of magnetic fields. Furthermore, based on the comparison of observations with the theory of hourglass fields, we can estimate and discuss the initial physical parameters for core formation. I also present a study to constrain the radiative torque grain alignment theory based on the near-infrared polarization-extinction relationship in cold and dense environments. - Facilitator
- Hiroshi Nagai, Xing Lu