Setting UBVRI Photometric Zero-Points Using Sloan Digital Sky Survey ugriz Magnitudes

Abstract

We discuss the use of Sloan Digital Sky Survey (SDSS) ugriz point-spread function (PSF) photometry for setting the zero points of UBVRI CCD images. From a comparison with the Landolt (1992) standards and our own photometry we find that there is a fairly abrupt change in B, V, R, & I zero points around g, r, i ~ 14.5, and in the U zero point at u ~ 16. These changes correspond to where there is significant interpolation due to saturation in the SDSS PSF fluxes. There also seems to be another, much smaller systematic effect for stars with g, r > 19.5. The latter effect is consistent with a small Malmquist bias. Because of the difficulties with PSF fluxes of brighter stars, we recommend that comparisons of ugriz and UBVRI photometry should only be made for unsaturated stars with g, r and i in the range 14.5 - 19.5, and u in the range 16 - 19.5. We give a prescription for setting the UBVRI zero points for CCD images, and general equations for transforming from ugriz to UBVRI.

13 pages. 6 figures. Accepted for publication in the Astronomical Journal

References in corpus (3)

• Empirical Color Transformations Between SDSS Photometry and Other Photometric Systems
• Improved $u^{\prime }{g}^{\prime }{r}^{\prime }{i}^{\prime }{z}^{\prime }$ to $UBV{R}_C{I}_C$ Transformation Equations for Main Sequence Stars
• Improved Photometric Calibrations for Red Stars Observed with the SDSS Photometric Telescope

Cited by in corpus (25)

• Multi-Element Abundance Measurements from Medium-Resolution Spectra. II. Catalog of Stars in Milky Way Dwarf Satellite Galaxies
• A Dynamical Analysis of the Kepler-80 System of Five Transiting Planets
• A Revised Broad-Line Region Radius and Black Hole Mass for the Narrow-Line Seyfert 1 NGC 4051
• PHOTOMETRYPIPELINE: An Automated Pipeline for Calibrated Photometry
• Supernovae 2016bdu and 2005gl, and their link with SN 2009ip-like transients: another piece of the puzzle
• Updated 34-Band Photometry for the SINGS/KINGFISH Samples of Nearby Galaxies
• A search for stellar tidal debris of defunct dwarf galaxies around globular clusters in the inner Galactic halo
• SN 2016X: A Type II-P Supernova with A Signature of Shock Breakout from Explosion of A Massive Red Supergiant
• Comprehensive Wide-Band Magnitudes and Albedos for the Planets, With Applications to Exo-Planets and Planet Nine
• The complex star cluster system of NGC 1316 (Fornax A)
• A Survey of Satellite Galaxies around NGC 4258
• SN 2017ivv: two years of evolution of a transitional Type II supernova
• Towards a fully consistent Milky Way disc model - II. The local disc model and SDSS data of the NGP region
• GRB 050502B optical afterglow: a jet break at high redshift
• Globular Clusters: DNA of Early-Type galaxies?
• Photometric and spectroscopic evolution of the peculiar Type IIn SN 2012ab
• SNhunt151: an explosive event inside a dense cocoon
• An Optical-UV-IR Survey of the North Celestial Cap: I. The Catalogue
• Observations of A Fast-Expanding and UV-Bright Type Ia Supernova SN 2013gs
• Bridging the Ultraviolet and Optical Regions: Transformation Equations between {\it GALEX} and {\it UBV} Photometric Systems
• The main sequence from F to K stars of the solar neighbourhood in SDSS colours
• Photometric Calibration of the $[\alpha /$Fe] Element: II. Calibration with SDSS Photometry
• Metallicity and absolute magnitude calibrations for F-G type main-sequence stars in the Gaia era
• Photometric observations of the supernova 2009nr
• Absolute Magnitude Calibration for Dwarfs Based on the Colour-Magnitude Diagrams of Galactic Clusters