�y��vlog

In the latter case, being determined by observations of the sun, it is taken to begin with the passage of the mean sun over the meridian of the place, or at mean noon, while the civil day begins at midnight.

The circles on the tracks indicate the position of the storm centres at Greenwich mean noon on successive days.

The + sign indicates that the real sun reaches the meridian after mean noon; the − sign before mean noon.

There you find the Right Ascension of the Mean Sun at Greenwich Mean Noon for every day in the year.

The result will be the distance in sidereal time the star is from your meridian i.e., the time interval from local mean noon expressed in units of sidereal time.