Infrared and submillimetre studies of Vega-excess stars |
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| Authors: | Coulson Walther & Dent |
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| Institution: | Joint Astronomy Centre, 660 N. Aohoku Place, Hilo, HI 96720, USA,;Gemini 8m Telescope Project, 180 Kinoole St., Suite 209, Hilo, HI 96720, USA,;Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ |
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| Abstract: | We report new infrared and submillimetre observations of a sample of 24 candidate Vega-excess stars, and derive CO masses, dust masses, gas to dust ratios and the strengths of various emission lines. Most of these stars have dustier discs than the class archetypes (Vega, Fomalhaut, β Pic, etc.), yet, like the archetypes, all the stars observed in CO show the gas content of their discs to be depleted compared with molecular cloud values. We discuss how the extra dust content might imply that these stars are less evolved than the archetypes, and use other infrared and submillimetre characteristics to support this contention. |
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| Keywords: | dust extinction ISM: molecules infrared: stars |
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