The following document lists the file abstract/PHAMMERS_PSNSTAR.abs
from catalogue VI/111.
A plain copy of the file
(without headers/trailers) may be downloaded.
SCIENTIFIC ABSTRACT The aim is to obtain accurate monochromatic fluxes for a representative sample of star classes and spectral types, over a wide wavelength range. The stars should be normal in the sense that they are single and have no known infrared excesses. The recognition of 'normal stars ' which have infrared excesses less than 1% is not easy. A few stars with large excesses, such as Vega, are known to exist, but little is known on the proportion with smaller excesses. This study will help to establish normal stars. We wish to compare the measured fluxes with model atmospheres and then use the Infrared Flux method to determine angular diameters and effective temperatures. OBSERVATION SUMMARY We wish to observe stars with a 2.2 micron fluxes of between 2700Jy and 30Jy. The fluxes have been estimated by extrapolating these fluxes to longer wavelengths assuming a normal photosphere. If the star has an excess these fluxes will be under estimates. At 10 microns the flux range is 272Jy to 3Jy and at 100 microns it is 3.7 to 0.04Jy. We wish to obtain photometry using PHT-P. We wish to use 5 filters aperture combinations in the PHT03 AOT. They are 10 microns/13.8", 16 microns/18", 25 microns/23", 60 microns/52" and 100 microns/99". The fluxes from the stars will be far larger than the background at the shorter wavelengths, the integration times will be 32 seconds and staring mode will be used. However at the longer wavelengths (60 and 100 microns) chopping will be required and for the fainter objects an increased integration time is needed to obtain high S/N. We wish to uses both gratings of PHOT-S. The integration for the brighter stars will be 32 seconds but this will be increased to 128 seconds for the faintest stars. The SWS spectra are required to identify and measure blocking features. We require medium resolution and the AOT SWS01 with a total integration time of 12.7 mins will be sufficient.