... ATNF Home . About ATNF . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Parkes radio telescope . ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... We discuss variations of the atmospheric extinction coefficients and transformation equations to the standard UBVRI system based on observations of standard stars during 1996-1997 at Siding Spring Observatory using a thinned SITe CCD and coloured glass filters. ... Standard System Transformations . ...

... The absolute flux calibration of NICMOS will be calculated from observations of standard stars with known flux distributions F( ). ... In order to expand the set of IR standard stars in the appropriate flux range for NICMOS, M. Rieke, R. Thompson, and collaborators at the University of Arizona are making photometric observations of solar-analog stars, which will be used to normalize the solar spectrum to the observed IR magnitudes. ... Relative flux references accurate to 1.5% for standard...

... Public . Science . ... Science Users Information > Observing with ESO Telescopes > Observing Tools and Services > Archives and Catalogues . ... Public Surveys . Publications with ESO Data . ... Large Programmes . ... Public Surveys Programmes . ... The following Archives and Catalogues can be helpful for proposal preparation and for preparing an observing run. ... For a comprehensive overview of the on-line ESO/ST-ECF archives and catalogues please refer to the Science Archive Facility . ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... Updates to HST Standard-Star Fluxes . ... These data are in an STScI data base named CRCALSPEC and have been divided into two categories to help the user understand the origin and accuracy of these flux distributions. ... 1990, ApJS, 73, 413) and Oke (1990, AJ, 99, 1621) spectra are available. Oke (1990) used the DoubleSpectrograph on the 5-m Hale Telescope to obtain these spectra for HST calibration; and these data are identified in the HST data bases by the keyword OBSMODE=OKE DBSP. ...

Peremennye Zvezdy", . ... 6, N 19 (2006) . ... Star Name: . ... Fourier-decomposition of the light curves shows frequency peaks at 1.55 c/d and its ?1.0 day aliases. ... V lightcurve and B-V, V-R C , V-I C colour index curves are shown, folded with the period of P=0.645 days. ... 2006, IBVS 5709 . ... Light Curve . USNO-B1.0 1305-0178165 relative V light curve and relative B-V , V-R C and V-I C colour index curves, from top to bottom, respectively, folded with the 0.645d period of the variation. ...

System of astrometric databases of Pulkovo observatory. ... The purpose of these observations is the determination of precise coordinates of Solar system bodies, which is necessary for development and improvement of motion theories, and for studying the evolution of the Solar system. ... Accuracy of photographical observations is about 0.2-0.3 arcsec for equatorial coordinates and 0.1-0.3 for relative coordinates of planetary satellites, depending on object and observational conditions. ...