V and R Magnitudes for Planetary Nebula Central Stars in the MACHO Project Galactic Bulge Fields

Session 53 - SNs, Planetaries and Circumstellar Disks.
Display session, Wednesday, June 10
Atlas Ballroom,

[53.09] V and R Magnitudes for Planetary Nebula Central Stars in the MACHO Project Galactic Bulge Fields

J. Lutz (WSU), D. Alves (LLNL), A. Becker (UW), T. Vandehei, K. Griest (UCSD), M. Lehner (Sheffield), C. Alcock, K. Cook, S. Marshall, D. Minniti (LLNL), R. Allsman, K. Freeman, B. Peterson, A. Rodgers (MSSSO), M. Pratt (MIT), C. Stubbs, A. B. Tomaney (UW), D. Bennett (Notre Dame), P. Quinn (ESO), W. Sutherland (Oxford), D. Welch (McMaster)

The MACHO Project has been monitoring selected fields in the galactic bulge since 1992. About 35 planetary nebulae (PN) with observable central stars are located within these fields. These PN are well worth investigating both for improvements in magnitude measurements and especially to check the possibility of variability. This is a preliminary report on data for 22 of the PN central stars. Cousins V and R magnitudes were measured for each of the stars; the V magnitudes range from 13.47 to 18.20. The quality of the photometry and problems encountered with reducing the data (e.g. objects near the edge of a field, cosmic ray hits) will be discussed as part of our paper. One central star, that of the PN Hf 2-2 (MACHO ID 139.32591.211), appears to be variable with a period of 0.398571 days.

Program listing for Wednesday