scientific abstract with iso, we propose to study the physical nature and evolutionary history of dust debris clouds around solar mass stars. these clouds, discovered by iras, are thought to be related to planetary systems. the program will consist of: (i) a photometric study of selected a, f, g, and k-type main sequence stars within 20 pc of the sun. 160 stars have been selected with various ages and multiplicity. (ii) a study of the evolutionary history of debris clouds from observations of 174 young open cluster stars and weak-line t tauri stars. (iii) search for excess emission from 34 known young main sequence field stars beyond 20 pc. (iv) search for possible dust disks around 12 degenerate stars. (v) search for infrared excess from 23 bright star catalog a & f stars which were not observed by iras. the investigation will clarify the relationship of the debris clouds, specific properties of stars, and place the phenomenon in the context of planetary formation. observation summary we will investigate the excess emission from main sequence and the other field stars at 60 micron and 100 micron using c100 in isophot, using the triangular chopping mode. for the cluster stars we will use a sparse map and c100 (pht37, pht38, and pht39). each observation consists of a single stare on the object and then a corresponding stare on an adjacent sky, separated by 2 arcmin. for stability of the detectors, all observations in a sequence will be done at one wavelength and then a repeated reverse sequence at a second wavelength; the two sequences are concatenated together. integration times on each of the source and sky will be typically 128 sec at 60 micron and 128 sec at 100 micron. the required signal to noise for these cluster stars is unknown, since the photosphere will not be seen and the amount of excess depends on the unknown dust density. we expect that the photosphere will be detected for most stars stars with a s/n > 5. for the degenerate white dwarfs and pulsars, the s/n will depend on the amount of circumstellar dust, which is uncertain. acquisition\t\t\t180 sec initial instrument setup\t 15 sec stability of detector\t\t 90 sec filter change (2 pos)\t\t 20 sec fcs exposures (for 2 filters)\t 32 sec integration at 60 micron\t256 sec integration at 100 micron\t256 sec total time\t\t\t849 sec
Instrument
PHT22 , PHT37 , PHT38 , PHT39
Temporal Coverage
1997-05-19T09:08:26Z/1998-02-04T17:05:09Z
Version
1.0
Mission Description
The Infrared Space Observatory (ISO) was the worlds 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.
