An all-sky set of photometric calibrators for Schmidt surveys^*

GSPC2.1: First release

¹ Astronomical Observatory of Torino, Strada Osservatorio 20, 10025 Pino Torinese TO, Italy
² Space Telescope Science Institute, 3700 S. Martin Drive, Baltimore, MD 21218, USA
³ Gemini 8-M Telescope Project, 670 N. A'ohoku Place, Hilo, Hawaii, 96720, USA
⁴ Visiting Astronomer, Kitt Peak National Observatory, National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation
⁵ Science Programs, Computer Sciences Corporation
⁶ Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago, Chile
⁷ Visiting Astronomer, Cerro Tololo Inter-American Observatory, National Optical Astronomy Observatories, which is operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation
⁸ Leiden Observatory, University of Leiden, PO Box 9513, 2300 RA Leiden, The Netherlands
⁹ European Southern Observatory, Casilla 19001, Santiago 19, Chile

B. Bucciarelli

Received: 31 October 2000
Accepted: 5 December 2000

Abstract

We publish 622 CCD photometric sequences in the Johnson-Kron-Cousins standard system, distributed both in the northern and southern hemispheres, useful for the calibration of photographic photometry of Schmidt survey plates. The collection and reduction of the CCD data presented here are part of a long-term program devoted to the construction of the Second Guide Star Photometric Catalog (GSPC-II). The GSPC-II is an all-sky catalog of photometric stellar sequences with a limiting magnitude of or fainter, in the , V, and R passbands of the Johnson-Kron-Cousins system. Standard photometric errors are at the level of ∼0.07 for a magnitude star. These sequences are being used by teams of the Space Telescope Science Institute (STScI) and the Osservatorio Astronomico of Torino (OATo) for the photometric calibration of the Second Guide Star Catalog.