= > otac solicited proposal = note: the project is an otac solicited proposal. the data will be made public within 1 month of despatch from esa on the public ftp/www server of the iso soc. one of the exciting discoveries made using iras was the dust disc around vega and other evolved stars. so far, only beta pic has had its disc confirmed optically. due to the low spatial resolution of iras, relatively little is known about the immediate environment of beta pic in the infrared. isophot is being used to make oversampled maps (pht32 at 60um and 90um, h. walker et al), as well as for long wavelength photometry and low resolution spectroscopy. the reduction of the otf from 10 to 2 arcsec has made high resolution scans possible. recently the p3 detector was used to scan vega at 60um, using an aperture below the diffraction limit and with a very small step size, giving a high resolution scan across the disc. this showed the extent of the disc very clearly when compared to the point source gamma dra (hr6705). this new observing technique, resulting from iso.s excellent pointing accuracy, means that the airy disc can be sampled with around 7 to 8 positions across it, revealing the extended dust disc with ease. we propose to use this method on beta pictoris at 25 and 60 microns to perform 4 scans across beta pic using the p3 detector as indicated above and 8 scans using the p2 detector at 25 microns. we also request the identical scan pattern to be repeated across gamma dra (hr6705), for confirmation of the behaviour of the detector for a genuine point source (from the influence of the tripod).
Instrument
PHT03
Temporal Coverage
1997-12-18T19:00:34Z/1997-12-21T03:48:03Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the world's first true orbiting infrared observatory. Equipped with four highly-sophisticated and versatile scientific instruments, it was launched by Ariane in November 1995 and provided astronomers world-wide with a facility of unprecedented sensitivity and capabilities for a detailed exploration of the Universe at infrared wavelengths.
