Improved Photometric Calibrations for Red Stars Observed with the SDSS Photometric Telescope

We present a new set of photometric transformations for red stars observed with the Sloan Digital Sky Survey (SDSS) 0.5 m Photometric Telescope (PT) and the SDSS 2.5 m telescope at the Apache Point Observatory in New Mexico. Nightly PT observations of US Naval Observatory standards are used to determine extinction corrections and calibration terms for SDSS 2.5 m photometry. Systematic differences between the PT and native SDSS 2.5 m ugriz photometry require conversions between the two systems which have previously been undefined for the reddest stars. By matching ∼43,000 stars observed with both the PT and SDSS 2.5 m, we extend the present relations to include low-mass stars with colors 0.6 ≤ r - i ≤ 1.7. These corrections will allow us to place photometry of bright, low-mass trigonometric parallax stars previously observed with the PT on the 2.5 m system. We present new transformation equations and discuss applications of these data to future low-mass star studies using the SDSS.

[1]  Andrew A. West,et al.  Stellar SEDs from 0.3 to 2.5 μm: Tracing the Stellar Locus and Searching for Color Outliers in the SDSS and 2MASS , 2007, 0707.4473.

[2]  J. Davenport,et al.  Sloan/Johnson‐Cousins/2MASS Color Transformations for Cool Stars , 2006, astro-ph/0611087.

[3]  Andrew A. West,et al.  Low-Mass Dwarf Template Spectra from the Sloan Digital Sky Survey , 2006, astro-ph/0610639.

[4]  J. Bochanski,et al.  Using the Galactic Dynamics of M7 Dwarfs to Infer the Evolution of Their Magnetic Activity , 2006, astro-ph/0609001.

[5]  Walter A. Siegmund,et al.  # 2006. The American Astronomical Society. All rights reserved. Printed in U.S.A. THE 2.5 m TELESCOPE OF THE SLOAN DIGITAL SKY SURVEY , 2005 .

[6]  Pennsylvania State University,et al.  Seventy-One New L and T Dwarfs from the Sloan Digital Sky Survey , 2006, astro-ph/0601089.

[7]  S. Hawley,et al.  Updated Colors for Cool Stars in the Sloan Digital Sky Survey , 2005 .

[8]  Andrew A. West,et al.  The χ Factor: Determining the Strength of Activity in Low‐Mass Dwarfs , 2004, astro-ph/0410422.

[9]  A. Szalay,et al.  SDSS data management and photometric quality assessment , 2004, astro-ph/0410195.

[10]  J. Brinkmann,et al.  Spectroscopic Properties of Cool Stars in the Sloan Digital Sky Survey: An Analysis of Magnetic Activity and a Search for Subdwarfs , 2004, astro-ph/0403486.

[11]  Ž. Ivezić,et al.  Astrometric Calibration of the Sloan Digital Sky Survey , 2002, astro-ph/0211375.

[12]  Johns Hopkins University,et al.  Characterization of M, L, and T Dwarfs in the Sloan Digital Sky Survey , 2002, astro-ph/0204065.

[13]  Kazuhiro Shimasaku,et al.  The ugriz Standard-Star System , 2002 .

[14]  D. York,et al.  The u'g'r'i'z' Standard Star Network , 2002, astro-ph/0201143.

[15]  J. Gunn,et al.  A Photometricity and Extinction Monitor at the Apache Point Observatory , 2001, astro-ph/0106511.

[16]  Walter A. Siegmund,et al.  The Sloan Digital Sky Survey: Technical Summary , 2000, astro-ph/0006396.

[17]  et al,et al.  The Discovery of a Field Methane Dwarf from Sloan Digital Sky Survey Commissioning Data , 1999, astro-ph/9905391.

[18]  Xiaohui Fan,et al.  Simulation of Stellar Objects in SDSS Color Space , 1999, astro-ph/9902063.

[19]  Walter A. Siegmund,et al.  The Sloan Digital Sky Survey Photometric Camera , 1998, astro-ph/9809085.

[20]  M. Fukugita,et al.  The Sloan Digital Sky Survey Photometric System , 1996 .

[21]  Lee.  The Astronomische Nachrichten , 1858 .

[22]  John E. Davis,et al.  Sloan Digital Sky Survey: Early Data Release , 2002 .

[23]  Paolo Persi,et al.  The Impact of Large Scale Near-IR Sky Surveys , 1997 .