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The Subaru Seminar is usually held in Room 104 of the Hilo Base Facility, adjacent to the main lobby. Everyone is welcome to attend. If you are interested in giving a seminar, please contact Masayuki Akiyama by email.

Augast 11, Monday at 10:00am

"A spectro-astrometric study of pre-main sequence stars
--- Probing AU-scale structure --- "

Michihiro Takami (University of Hertfordshire, UK)

The circumstellar environment within 10 AU of young stars is of particular interest for studies of star and planet formation. In this region, the star accretes the material from the circumstellar disk, and drives an energetic jet/wind. In the circumstellar disk, planets may be growing and tidally interacting with the circumstellar environment. In a significant number of objects, this region also contains a stellar companion. The population, mass distribution, and orbital parameters of these companions could give useful constraints on the understanding of binary formation. However, even the Hubble Space Telescope or adaptive optics on 10-m telescopes cannot resolve this scale in the nearest star-forming regions. To obtain spatial information at such high resolutions, we use the technique of ``spectro-astrometry''. By use of a standard long-slit spectrograph, the seeing position relative to the continuum is measured in emission/absorption features with an extremely high accuracy (~1 mas). We have proved that this method is capable of discovering pre-main sequence binaries, determining kinematics of outflows and providing evidence for gaps in circumstellar disks --- all down to AU scales. I summarise our progress to date, and present some recent results obtained at the SUBARU 8.2-m telescope.



Seminars are also held at JAC, CFHT, and IfA.



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