Description
In January 1997, at the Observatsrio Nacional (ON), Rio de Janeiro, Brazil, digital CCD observations of the solar diameter began with a Danjon astrolabe adapted for solar observations and equipped with a variable angle reflecting prism. The prism enables observations of the Sun several times per day and all year round at the southern latitude {phi}=-22{deg} 54'. As of June 1999, about 9000 observations have been made. The mean value of the apparent semi-diameter is 959.13"+/-0.01". Here we report on the results obtained between July 1998 and June 1999. In 162 days 4276 observations were made. For this period the mean apparent semi-diameter is 959.07"+/-0.02". No significant difference between the apparent semi-diameters is found as observed on the East and West sides of the meridian.
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