VizieR Online Data Catalog: Catalogue of stellar ultraviolet fluxes (TD1): A compilation of absolute stellar fluxes measured by the Sky Survey Telescope (S2/68) aboard the ESRO satellite TD-1

The Belgian/UK Ultraviolet Sky Survey Telescope (S2/68) in the ESRO TD1 satellite carried out a controlled scan of the whole sky. It measured the absolute ultraviolet flux distribution between 2740A (274nm) and 1350A (135nm) of point sources down to tenth visual magnitude for unreddened early B stars. The S2/68 experiment has been described by Boksenberg et al. (=1973MNRAS.163..291B) and the absolute calibration by Humphries et al. (=1976A&A....49..389H). The catalog contains results from the sky-scan experiment in the TD1 satellite of the European Space Research Organization. The catalog lists the absolute ultraviolet fluxes in four passbands: --------------------------------------------------------- Passband Center: 274.0nm 236.5nm 196.5nm 156.5nm Effective Width: 31.0 33.0 33.0 33.0 --------------------------------------------------------- for 31215 stars. The stars have been selected subject to the constraint that the signal-to-noise ratio should be at least 10.0 in any one of the four passbands. Many of the fainter stars of spectral types later than A5 do not have significant signals in all of the spectrophotometric channels (particularly the 1565A channel). Consequently, after the removal of the background, they can randomly give rise to small negative values of flux. We have decided not to suppress these negative values but to give them together with their error as they can be significant when considered as part of a statistical sample. Although the sky coverage is essentially complete, the catalogue does not contain the fluxes for all stars that fall within the limit of the sensitivity of the instrument. If any star expected to be present is missing, then its signal is probably blended with that of a nearby star in which case the data have been discarded. The fluxes F(lambda), and errors, sigma(lambda), can be transformed to the visual magnitude scale using the absolute calibration of Haynes & Latham (=1975ApJ...197..593H): m(lambda) = -2.5 log10 F(lambda) - 21.175 sigma_m(lambda) = 1.086 sigma(lambda)/F(lambda) Also: F(nu) = 3.336x10^-19 lambda^2 F(lambda) m(nu) = -2.5 log10 F(lambda) - 5 log10 lambda - 18.724 sigma_m(nu) = 1.086 sigma(lambda)/F(lambda) where F(lambda) is in units of erg.cm^-2.s^-1.A^-1 (mW/m2/(0.1nm)) lambda is in Angstroms and F(nu) is in units of erg.cm^-2.s^-1.Hz^-1 (mW/m2/Hz = 10²³Jy) (1 data file).