NOAO >   Observing Info >   Approved Programs >   2010A-0459

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Proposal Information for 2010A-0459


PI: Tsuyoshi Sakamoto, Japan Spaceguard Association, sakamoto@spaceguard.or.jp
Address: Bisei Spaceguard Center, 1716-3, Ookura, Bisei, Ibara, Okayama 714-1411, Japan

CoI: Takashi Hasegawa, Gunma Astronomical Observatory

Title: Stellar dynamics in the Milky Way out to the solar radius

Abstract: Dynamical properties of stars in Galactic disk provide important clues in understanding the gravitational fields of the bar and spiral arm as well as their dynamical evolution. Previous works showed that some of the disk stars have non-circular motion and they are closely related to the evolution of the bar and spiral arm. However, the formation process of the non-circular motion still remain unclear due to the limited size of sample or its spatial extent. Short-period Mira variable (SP-Miras) stars are good tracers for determination of the dynamical properties because they are a luminous and relatively old population and their periods are good distance indicators. We suggested that the systematic motion toward the anti-Galactic center exists in the Galactic radius, R=5-7 kpc along the major axis of the bar on the basis of the full space motions of the SP-Miras. In this semester, we propose to measure the radial velocities for 43 SP-Miras with no radial velocities in R=7-9 kpc along the major axis of the bar, and set limits on whether or not the non-circular motion in R=5-7 kpc and solar neighborhood is related to the bar.


National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360



NOAO >   Observing Info >   Approved Programs >   2010A-0459

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