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Published October 20, 2001 | Accepted Version + Published
Journal Article Open

Millimeter-Wave Aperture Synthesis Imaging of Vega: Evidence for a Ring Arc at 95 AU


We present the first millimeter-wave aperture synthesis map of dust around a main-sequence star. A 3'' resolution image of 1.3 mm continuum emission from Vega reveals a clump of emission 12'' from the star at a position angle (P.A.) of 45°, consistent with the location of maximum 850 μm emission in a lower resolution James Clerk Maxwell Telescope/Submillimeter Common-User Bolometric Array (SCUBA) map. The flux density is 4.0 ± 0.9 mJy. Adjacent 1.3 mm peaks with flux densities of 3.4 ± 1.0 and 2.8 ± 0.9 mJy are located 14'' and 13'' from the star at P.A.'s of 67° and 18°, respectively. An arclike bridge connects the two strongest peaks. There is an additional 2.4 ± 0.8 mJy peak to the southwest, 11'' from the star at P.A. = 215°, and a marginal detection, 1.4 ± 0.5 mJy, at the stellar position, consistent with photospheric emission. An extrapolation from the 850 μm flux, assuming F_(1.3-0.85 mm) ∝ λ^(-2.8), agrees well with the total detected flux for Vega at 1.3 mm and implies a dust emissivity index β of 0.8 We conclude that we have detected all but a very small fraction of the dust imaged by SCUBA in our aperture synthesis map and that these grains are largely confined to segments of a ring of radius 95 AU.

Additional Information

© 2001 The American Astronomical Society. Received 2001 August 14; accepted 2001 September 6; published 2001 September 25. We are grateful to all OVRO postdoctoral scholars and visiting astronomers who helped in acquiring the data, but especially to Kartik Sheth. The OVRO millimeter array is supported by the NSF through grant AST 99-8154. OVRO research on other solar systems is also supported by the Norris Planetary Origins Project and NASA Origins grant NAG5-9530.

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Published - Koerner_2001_ApJ_560_L181.pdf

Accepted Version - 0109424.pdf


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August 19, 2023
October 20, 2023