ISO Spectral Energy Distributions for Vega-type Stars

Session 47 - Circumstellar Disks & Shells.
Display session, Thursday, January 08
Exhibit Hall,

[47.13] ISO Spectral Energy Distributions for Vega-type Stars

N. Thakur, S. B. Fajardo-Acosta, R. E. Stencel (U. Denver-Astronomy), D. E. Backman (Franklin and Marshall College)

We present new infrared photometry of main-sequence stars in order to determine the frequency of mid- and far-infrared excesses in their spectral energy distributions. These observations constitute NASA Key Project VEGADISK (Stencel amp; Backman 1994, Apamp;SS, 212, 417). We used the Infrared Space Observatory's (ISO) ISOPHOT instrument at wavelengths of 3.6, 11.5, 20, 60, and for some stars, 90 \mum, with a uniform 52 arcsec aperture. Final calibration of ISOPHOT data is not available from the ISO Project, so we have compared the fluxes obtained from ISO, IRAS, and ground-based observations to standardize our preliminary flux values. On this basis, nearly 25% of our stars show infrared excesses in our sample. We will report on the correlation of these excesses with stellar age.

Program listing for Thursday