Solar Astrometry Service

This Service had been dedicated to monitoring the Earth's rotation but due to current scientific needs it has evolved to carry out the systematic study of the parameters of the Sun. In the last years, as part of international cooperation, this instrument has been used to observe the upper and lower limbs of the Sun in its E and W transits for the +45º almicantarat in order to determine the apparent variations of its diameter. Once this collaboration finished, the instrument remains operative to carry out new projects.

The modified Danjon Astrolabe, equipped with an azimuth-positioner automatic system and a CCD camera, is an instrument that can be used in the R.O.A. despite the environmental adverse conditions for astronomical observations. The daily determination of the solar diameter is of great importance for the confirmation of the astrophysical theories that describe the physical behaviour of the Sun. The detection of significant changes in the value of the solar diameter is of considerable importance for the understanding of solar physics and the Earth's atmosphere response to solar activity.