BIB-VERSION:: AST-PP-v1.0
ID:: epreps.stsci//prep1218
ENTRY:: March 9, 1998
TITLE::  New Distance Determination to the LMC 
SUBTITLE:: 
AUTHOR:: Panagia, Nino
AFFIL:: Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA On assignment from the Astrophysics Division, Space Science Department of ESA
DATE:: February 1998
JOURNAL:: To appear in: 
SUBMITTED::
ACCEPTED::
OTHER_ACCESS:: 
COPYRIGHT:: Copyright 1998 The Association of Universities for Research in Astronomy, Inc.  All Rights Reserved.
LANGUAGE:: English
ABSTRACT::

Using the new reductions of the IUE light curves by Sonneborn et
al (1997) and an extensive set of HST images of SN 1987A we have
repeated and improved Panagia <I>et al</I> (1991) 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<FONT SIZE=-1><SUB>abs</SUB></FONT>&nbsp;=&nbsp;(6.23&plusmn;0.08)
&times;10<FONT SIZE=-1><SUP>17</SUP></FONT>&nbsp;cm and an angular
size R"&nbsp;=&nbsp;808&plusmn;17&nbsp;mas, which give a distance
to the supernova d(SN 1987A)&nbsp;=&nbsp;51.4&plusmn;1.2&nbsp;kpc and
a distance modulus m-M(SN 1987A)=18.55&plusmn;0.05.
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)&nbsp;=&nbsp;52.0&plusmn;1.3&nbsp;kpc,
which corresponds to a distance modulus of m-M(LMC)=18.58&plusmn;0.05.
Revising accordingly the zero point of the Cepheid distance scale,
and using the SNIa measured by Sandage and collaborators, one finds 
a value of the Hubble constant
<NOBR>H<FONT SIZE=-1><SUB>0</SUB></FONT> = 
60&plusmn;6 km s<FONT SIZE=-1><SUP>-1</SUP></FONT> Mpc<FONT SIZE=-1><SUP>-1</SUP></FONT>.</NOBR>

END:: epreps.stsci//prep1218