UVBRI imaging photometry of Eta Carinae region

Abstract

CCD Images of a large area of the Eta Car Nebula are presented. The area covers some 60 by 30 arcmin. The images presented here were taken with a Tektronix 1024 x 1024, blue sensitive CCD on the 1m Swope Telescope of the Las Campanas Observatory. The images are sampled to .67 arcsec per pixel. The average seeing during the observing run was of the order of 1.3 arcsec. Conditions were, in general, not photometric but individual frames have been calibrated with previous photometry reported in several papers by Feinstein and Co-workers. Our survey has a dynamic interval of some 8 magnitudes and includes stars to a limit of m=20 in B and V m=18 in U, R and I. Preliminary photometric calibrations indicate that we are observing the main sequence down to a mass limit approximately 0.5 M⊙. When combined with JHK photometry (see Roth et al., this meeting) we expect to determine in greater detail the characteristics of the interstellar reddening, based on a much bigger sample of stars and colors than currently available. These data information will also enable us to construct more accurately the Initial Mass-Function of this young region.