Here's and example for a few days around the Winter Solstice.
Date..................Distance
Nov 14 0.9893178 A.U
21 0.9877909
28 0.9864777
Dec 5 0.9854100
12 0.9845386
19 0.9838419
26 0.9834050
31 0.9832777
Multiply the distance above by the mean distance to the Sun to get its actual distance in miles or kilometers. There is a great 'solar Ephemeris' calculator at the Osservatorio Astronomico di Capodimonte in Italy as of May 2000. Enter your date and time, and it calculates the heliographic coordinates including the diameter of the Sun, and its distance in Astronomical Units
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