@astroilin
That is huge, so it would take about 1200 seconds for light to travel from one side to the other.
If it takes six seconds for light to travel from our Sun to Earth, a distance of 1AU
So a 100 AU radius would giver a 200 Au diameter, if we multiply that by six seconds we get 1200 seconds, so a photon would take 1200 seconds to move across the diameter of the star,
If that even makes sense.
Still pretty awesome though.
@zleap Note that the astrosphere is not the same as the star. Proxima Cen is a tiny star actually, about 0.2 solar radii. Otherwise, the calculation is correct.