Session 19 - Source Surveys, Galaxy Surveys, Distance Scale II.
Display session, Wednesday, January 07
Exhibit Hall,

## [19.09] Improved Distance Determination to SN 1987A and the LMC

N. Panagia (STScI/ESA), R. Gilmozzi (ESO), R. P. Kirshner (CfA-Harvard), C. S. J. Pun, G. Sonneborn (GSFC), SINS Collaboration

Using the new reductions of the IUE light curves by Sonneborn et al (1997, ApJ, 477, 848) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al (1991, ApJ, 380, L23) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ring R_abs = (6.17 \pm 0.18) \times 10^17 cm and an angular size R^" = 808 \pm 17 mas, which give a distance to the supernova d(SN1987A) = 50.9 \pm 1.8 kpc and a distance modulus m-M(SN1987A) = 18.53 \pm 0.08. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to be d(LMC)=51.5\pm1.9 kpc, which corresponds to a distance modulus of m-M(LMC) = 18.56 \pm 0.08.