3 Conclusions

4276 digital CCD observations of the solar diameter during 12 months from July 1998 to June 1999 were made. The mean apparent semi-diameter is 959$.\!''$07 $\pm$ 0 $\hbox{$.\!\!^{\prime\prime}$ }$02. The difference between mean East and West apparent semi-diameters is 0 $\hbox{$.\!\!^{\prime\prime}$ }$03, which is non significant face the measurements errors.

Since 1997 near 9000 observations have been made. The mean value of the apparent semi-diameter for the entire series is 959$.\!''$13 $\pm$ 0 $\hbox{$.\!\!^{\prime\prime}$ }$01.

The error of a single observation of semi-diameter for the period of 1998-1999 is 0 $\hbox{$.\!\!^{\prime\prime}$ }$51 for the East and 0 $\hbox{$.\!\!^{\prime\prime}$ }$43 for West observations. The standard error of the daily mean observed semi-diameter is 0 $\hbox{$.\!\!^{\prime\prime}$ }$14.

Further observations are highly desirable to study the measured variations in time of the solar semi-diameter.

Acknowledgements

This work was partially supported by the CNPq/Brazil - CNRS/France binational agreement No. 910172/95-1. S.P. and E.G.J. thank CNPq/Brazil for the financial support under the contracts 300016/93-0 and 300017/93-6. This work was partially supported by FAPERJ.