Observations of HIPPARCOS Eclipsing Variables: EF Bootis, VZ Piscium, V417 Aquilae and BX Andromedae

We report ground-based observations and analysis of the HIPPARCOS eclipsing binaries EF Boo [HIP 71107] and VZ Psc [HIP 115819]. These systems were observed at Cerro Tololo InterAmerican Observatory in 1995 and at Lowell Observatory in 1999. Over 1200 observations were obtained in each of U, B and V filters for EF Boo and over 300 observations in each of U,B,V,R,I filters for VZ Psc. The precision was better than 1% in all pass bands. The photometry was transformed to the standard Johnson-Cousins UBVR_cI_c system. Absolute magnitudes were determined for VZ Psc. A period study and a complete synthetic light curve analysis are presented for each. Radial velocity curves are included in the analyses of VZ Psc. These data along with the authors's published UBV photometry of V417 Aql [HIP 96349] and BX And [HIP 10027] are compared to HIPPARCOS catalog data. We acknowledge partial support by a grant from NASA and administered by the American Astronomical Society. NWG participated in the Research Experiences for Undergraduates (REU) program at the Southeastern Association for Research in Astronomy (SARA) and sponsored by the National Science Foundation (NSF grant AST9619939).