Up: Observations of the Sun
After prior modifications the Danjon astrolabe is a reliable instrument
for solar observations (Laclare 1983). A program of astrometric
observations of the Sun at
and
zenith distances is
in progress since 1990 with the astrolabe of the National Astronomical
Observatory of Cerro Calán at Santiago, Chile. This program is a
contribution to the research of the orbital elements of the Earth-Moon
system. However, since the results of the observations are sensible to
the adopted semidiameter of the Sun, eventual variations of the apparent
solar radius can be also disclosed
(Noël 1997). The modifications
introduced in the Danjon astrolabe of Santiago, as well as the program
of solar observations and the reduction method, were described by
Chollet & Noël (1993). All the individual results of the observations made
since the beginning of the solar program in 1990, have been published
elsewhere and are available in electronic form
(Noël 1993, 1994, 1995).
With this paper the data set of solar observations results of Santiago
is updated with the results obtained during the period 1995-1997.
Up: Observations of the Sun
Copyright The European Southern Observatory (ESO)