5TH IMAGE AND PHOTOMETRIC VARIABILITY IN 2237+0305 (EINSTEIN CROSS)

CCD frames in R and I obtained with HRCam at the CFHT in 0."4 (FWHM) seeing on 1990 August 23.3 U.T. were combined to produce S/N > 500 images at 0."13/pixel sampling of the brighter components of the quasar gravitationally lensed by 2237 +/- 0305. Relative magnitudes (+/- < 0.01 mag), positions (+/- < 0."002) and angular sizes are derived for the four previously known quasar images and for the core of the lensing galaxy. Compared with Yee's [AJ, 95, 1331 [AJ, 95, 1331 (1988)] photometry, these data show components B brighter by 0.25 mag and C fainter by 0.15 mag while the brightness of A and D and the colors of all four images are unchanged. The general variability of all four components between 1986 and 1990 is discussed. The intrinsic dispersions of the intensity profiles are sigma < 0."08 for the quasar images and sigma = 0."21 X 0."15 +/- 0."05 (FWHM = 0."50 X 0."35) in P.A. = 83-degrees +/- 2-degrees for the galaxy core. Subtraction of these components leaves a fifth stellar image 4.5 +/- 0.3 mag fainter than component A and 0."07 +/- 0."035 SSE of the lensing galaxy center.