CS-22966-043 - A BRIGHT NEW FIELD SX PHOENICIS STAR SIMILAR TO THOSE IN NGC-5053

CS 22966-043 is an ultra-short-period pulsating star with high velocit y (RV = -266 km s(-1)) discovered during the course of a search for sp ectroscopic binaries among blue metal-poor field stars, in progress si nce 1992. With respect to period (0.0374 days), mean color ((B-V) = 0. 24), and metal abundance ([Fe/H] approximate to -2.4), it closely rese mbles the SX Phoenicis stars found among the blue stragglers in NGC 50 53. CS 22966-043 also is the primary of a spectroscopic binary with (p robable) period of 430 days. Light-travel time across the projected or bit, as large as 0.0037 days, must be added to the times of observatio n to combine data obtained in different years with minimal phase dispe rsion. If CS 22966-043 is, indeed, a blue straggler formed by binary i nteraction as is now generally believed, then it seems most probable t hat the interaction was one of mass transfer from the present-day seco ndary during its post-main-sequence evolution rather than merger of a close binary. The latter option would require that this rare field sta r was, in addition, a member of a primordial triple system.