\documentstyle{article}
  \title{Analysis of the Sun's observations with prismatic astrolabe}
\author{N.V. Leister
P.C.R. Poppe\\
Instituto Astronomico e Geofisico\\
Universidade de Sao Paulo\\
Caixa Postal 9638, 01065-970\\
Sao Paulo, Brazil}
\date{}


\begin{document}
\maketitle

  We show the results of a regular programme of observations of the
transits of the solar limbs through an equal altitude circle, with a
Danjon modified astrolabe.
A program of the observations of the Sun has been under way since 1974
at the Abrahao de Moraes Observatory ($-23^{\circ} 00,1',3h07m52s W$) of the Uni
-versity of Sao Paulo. The main purpose of this programme is to deter
-mine corrections E and A to the FK5 equinox and equator, as well as to
the Earth's orbital constants. However, the successive observations of
the transits of both limbs through the same altitude circle yield the
solar diameter as well. The first point we discuss here is the
determination of the equator and equinox corrections based on
observations of the Sun at mean epoch from 1988 to 1994. The values of
E and A indicate the corrections $0.10" \pm 0.04"$ and $0.07" \pm 0.07"$, 
respectively. Secondly, we present the possible variations of the solar
radius, wich are of interest, both because of their astrophysical
significance, and because of their  potential relation to the
terrestrial climate.


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Matthews (editors), 59-97 (1991) 

\end{document}
