Near-Infrared Coronagraphic Observations of the T Tauri Binary System UY Aur
| Autor: | Yumiko Oasa, Satoshi Mayama, Tomoyuki Kudo, Miki Ishii, Saeko S. Hayashi, Tae-Soo Pyo, Misato Fukagawa, Tomonori Hioki, Yoichi Itoh, Hitoshi Funayama, Masahiko Hayashi, Takayuki Nishikawa, Motohide Tamura |
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| Rok vydání: | 2007 |
| Předmět: |
Physics
Brightness Astrophysics::High Energy Astrophysical Phenomena Astrophysics (astro-ph) FOS: Physical sciences Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Astrophysics Radius Orbital period Accretion (astrophysics) T Tauri star Space and Planetary Science Magnitude (astronomy) Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Binary system Circumbinary planet Astrophysics::Galaxy Astrophysics |
| Zdroj: | The Astronomical Journal. 134:880-885 |
| ISSN: | 1538-3881 0004-6256 |
| Popis: | We present a near-infrared image of UY Aur, a 0.9" separated binary system, using the Coronagraphic Imager with Adaptive Optics on the Subaru Telescope. Thanks to adaptive optics, the spatial resolution of our image was ~0.1" in the full width at half maximum of the point spread function, the highest achieved. By comparison with previous measurements, we estimated that the orbital period is ~1640 yrs and the total mass of the binary is ~1.73 solar mass. The observed H-band magnitude of the secondary varies by as much as 1.3 mag within a decade, while that of the primary is rather stable. This inconstancy may arise from photospheric variability caused by an uneven accretion rate or from the rotation of the secondary. We detected a half-ring shaped circumbinary disk around the binary with a bright southwest part but a barely detectable northeast portion. The brightness ratio is ~57. Its inner radius and inclination are about 520 AU and 42, respectively. The disk is not uniform but has remarkable features, including a clumpy structure along the disk, circumstellar material inside the inner cavity, and an extended armlike structure. The circumstellar material inside the cavity probably corresponds to a clump or material accreting from the disk onto the binary. The armlike structure is a part of the disk, created by the accretion from the outer region of the disk or encounters with other stellar systems. 16 pages, 6 figures; accepted for publication in AJ |
| Databáze: | OpenAIRE |
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