rs cvn objects belong to an interesting class of close binaries which have spots covering a significant fraction of the surface area of the component stars leading to photometric variation. the infrared studies of these binaries are not as numerous as the optical studies. photometric observations in the infrared reveal that some of the systems have ir excesses, mostly observed in the k and 12 micron bands. the nature of the ir excess, its origin and its relationship to other indicators of spot activity or circumstellar matter are not known. we propose to investigate this aspect by obtaining a homogeneous set of data on the spectra of a selected sample of rs cvn binaries using the iso instruments. we have chosen a sample of 14 rs cvns which are known to have ir excess. we propose to obtain medium resolution spectra in the 2.5-12 micron range using the isophot pht-s spectrometer. for the brighter systems the spectrum will be extended to longer wavelength by making photometric observations at 25 and 50 micron enabling one to investigate the colour excesses. for most of these sources, the spectral type of each component is known; for 3 sources, the individual v magnitudes are also known. hence one can reliably estimate the expected photospheric spectrum which can be subtracted from the observed one yielding the excess spectrum and colours. these along with any spectral features seen will help to probe the nature and origin of the excess, and the circumstellar material if any.
Instrument
PHT03 , PHT22 , PHT40
Temporal Coverage
1996-12-11T01:22:16Z/1997-01-31T00:40:13Z
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.
