.
With the given data, in general case, the distance to the star CAN NOT be determined.
In order for it COULD be determined, at least one additional input value should be given : the angle between the direction
of the diameter at that time and the averaged direction to the star.
What CAN BE estimated and calculated, is the maximum possible distance
d = = = approximately = = 1.23*10^11 kilometers, based on the given data.
Notice that the nearest star to the Earth, Proxima Centauri, is, actually, 40,208,000,000,000 km away from the Earth,
according to VERY RELIABLE sources (see, for example, https://imagine.gsfc.nasa.gov/features/cosmic/nearest_star_info.html )
So, the post gives TOTALLY WRONG input data and represents, thus, a F A K E P R O B L E M.