Dust disks around Vega-like stars comma Part 3

scientific abstract the iras fluxes for the calibration star vega (alpha lyrae, hr7001) showed that the star had excess flux over that expected for a normal main sequence star. the infrared excess has been interpreted as a dust disk left over from the formation of the star. several other main sequence stars show a similar excess in their iras fluxes. beta pic (hr2020) has been the only star around which the dust disk has been detected at shorter wavelengths and studied, and this disk is seen edgeon. isophot gives us the opportunity to investigate the structure of the dust disks around several of these stars, using multiaperture and mapping observations, and to investigate deviations of the energy distribution from that expected from a blackbody with multifilter observations. spectra will be taken of all the stars, to look for dust features. observation summary the proposal is split into three parts, this is part 3. the times used in this part of the proposal are calculated using the manual. a 5 x 5 raster map will be performed with pht32, using an oversampling factor of 2, which results in a map area 258 x 138 being covered. an integration time of 2 seconds/chopper plateau is used, which means that the time per raster position is 26 seconds (13 chopper steps/raster position). truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]