These hex plots presume that the distance between the center of one hex and the center of another is 1.0 parsec, thus the inner radius is 1/2 parsec and the outer radius is 1/sqrt(3) parsec.

Alpha Centauri is moving, and Proxima Centauri, in "far companion" orbit of Alpha Centauri, is moving with it. By Imperial Year (3rd Imperium) 6000 or so, Proxima will be close enough that it will be in our adjacent hex, not the hex after that. Unfortunately, hex maps fall down a little when used this way, as the distance from the far edge of one hex to the most distant edge of the adjacent hex is 2 parsec, though everything with in both hexes is Jump-1 away. So this is for fun, but it shows another difficulty of trying to map the real world into Traveller - it's not just a 3d-2d thing, but a "hex quantization" problem as well.

That said, the scale of a hex is an interesting topic. Here the Sun, the orbit of Sedna (80-800 au orbit around the sun), and Alpha Centauri A+B (barycenter) and Proxima Centauri, presently >12000 AU away from Alpha Centauri) are plotted against the dimensions of a hex.

The leftmost hex is Terra's. You can barely see in the center of the hex the orbit of Sedna - far, far beyond the orbit of Neptune or Pluto yet still a tiny speck compared to the area a hex represents.

The Orange and Red lines represent Alpha and Proxima Centauri, respectively. They are solid lines from their positions now (AD 2017) to imperial year 1116, and then dashed lines representing their paths for the next 22000 years. You can see that the orbital motion of Proxima around Alpha Centauri A+B is so slow that in the 26000 years or so being plotted, it barely moves in relative position to Alpha Centauri. The orbital period of Proxima is about 547,000 years - by the time Proxima completes an orbit it will be dozens of light years away from Terra.