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We describe the Yale/San Juan Southern Proper Motion (SPM) Catalog 1.0, which provides positions, absolute proper motions, and photographic BV photometry for 58,880 objects at the South Galactic pole. The sky coverage of the SPM Catalog 1.0 is about 720 deg2 in the magnitude range 5 \ V \ 18.5. About 55% of all catalog stars are randomly chosen, whereas the remainder contains numerous astrophysically interesting objects drawn from various lists and databases. The accuracy of positions and absolute proper motions is 40È150 mas and 3È8 mas yr~1, respectively, depending on the starÏs magnitude. The high-end astrometric accuracy applies to the stars brighter than V \ 15. A great deal of e †ort was put into correcting positions and proper motions for the magnitude-dependent systematic errors. The catalog can be used for Galactic structure studies and deep CCD-frame astrometric calibration and as a database for stars, galaxies, and other objects at the south Galactic pole. The catalog is supplemented by calibrated CCD BV photometry in selected 13@ ] 13@ areas.

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This paper reports X-ray spectral observations of a relatively nearby (z ¼ 0:048) BL Lac object 1ES 1959+65, which is a potential TeV emitter. The observations include 31 short pointings made by the Unconventional Stellar Aspect (USA) experiment on board the Advanced Research and Global Observation Satellite (ARGOS), and 17 pointings by the Proportional Counter Array (PCA) on board the Rossi X-Ray Timing Explorer (RXTE). Most of these observations were spaced by less than 1 day. 1ES 1959+65 was detected by the ARGOS USA detector in the range 1-16 keV, and by the PCA in the 2-16 keV range but at different times. During the closely spaced RXTE observations beginning on 2000 July 28, the ending of one flare and the start of another are visible, associated with spectral changes, where the photon index C ranges between $1.4 and $1.7, and the spectrum is harder when the source is brighter. This implies that 1ES 1959+65 is an X-rayselected BL Lac type (XBL) blazar, with the X-ray emission likely to originate via the synchrotron process. The USA observations reveal another flare that peaked on 2000 November 14 and doubled the flux within a few days, again associated with spectral changes of the same form. The spectral variability correlated with the flux and timing characteristics of this object that are similar to those of other nearby BL Lac objects and suggest relativistic beaming with a Doppler factor ! 1:6 and magnetic fields on the order of a few milligauss. We also suggest that the steady component of the X-ray emission-present in this object as well as in other XBLs-may be due to the large-scale relativistic jet (such as measured by Chandra in many radio-loud active galactic nuclei) but pointing very closely to our line of sight.