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Session 45 - Supernovae.
Display session, Tuesday, January 14
We present the JHK photometric evolution of the supernova SN1987A in the Large Magellanic Cloud, based on almost 10 years of observations at CTIO. Our final data point at the time of the submission of this abstract is for day 3274 after explosion, where we find (JHK) = (17.14,17.28,17.14) with an error of 0.04 mag for psf photometry. The photometry was measured relative to star 2 (in the numbering system of Walker and Suntzeff, 1990, PASP, 102, 131) where we measured (K,J-K,H-K)=(15.17,0.05,-0.01) with an error of 0.03 mag. Star 3, a known Be star, is variable in the near-infrared.
The supernova is now barely declining in the near-infrared flux. Over the last 4 years, the decline in K has been roughly linear at 0.23\pm 0.02 mag year^-1. The supernova is clearly non-stellar in the images, and aperture photometry to a radius of 1.0\arcsec\ is 0.3 mag brighter than the psf photometry.
We also present a deep K,J-K color-magnitude diagram of the LMC field within 50\arcsec\ of the supernova.
Program listing for Tuesday