Calibrated griz magnitudes of Tycho stars: All-sky photometric calibration using bright stars
- Creators
- Ofek, Eran O.
Abstract
Photometric calibration to ~5% level is frequently needed at arbitrary celestial location. However, existing all-sky astronomical catalogs do not reach this accuracy, and time consuming photometric calibration procedures are required. I fitted the Hipparcos B-T and V-T magnitudes, along with the 2MASS J, H, and K magnitudes of Tycho-2-catalog stars with stellar spectral templates. From the best-fit spectral template derived for each star, I calculated its synthetic SDSS griz magnitudes and constructed an all-sky catalog of griz magnitudes of bright stars (V ≾ 12). Testing this method on SDSS photometric-telescope observations, I find that the photometric accuracy, for a single star, is usually about 0.12, 0.12, 0.10, and 0.08 mag (1 σ), for the g, r, i, and z-bands, respectively. However, by using ~10 such stars, the typical errors per calibrated field (systematic + statistical) can be reduced to about 0.04, 0.03, 0.02, and 0.02 mag, in the g, r, i, and z-bands, respectively. Therefore, in cases for which several calibration stars can be observed in the field of view of an instrument, accurate photometric calibration is possible.
Additional Information
© 2008 Astronomical Society of the Pacific. Received 2008 June 06; accepted 2008 August 13; published 2008 October 2. I would like to thank the referee for constructive comments. I thank Shri Kulkarni for expressing the need for an all-sky catalog of standard stars, and to Avishay Gal-Yam, Dovi Poznanski, Orly Gnat, and Andrew Pickles for valuable discussions. This work is supported in part by grants from NSF and NASA.Attached Files
Published - OFEpasp08.pdf
Files
Name | Size | Download all |
---|---|---|
md5:eeebb15e2d22fc2fceee353b008ebb91
|
139.2 kB | Preview Download |
Additional details
- Eprint ID
- 13615
- Resolver ID
- CaltechAUTHORS:OFEpasp08
- NSF
- NASA
- Created
-
2009-03-04Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field