The point set for star1k consists of the locations of the nearest 1,000 stars in the Gaia DR1 instance of the TSP. The xyz triples of coordinates are listed in each of the following two files, one star per per line.
• star1k.xyz, list of coordinates
• star1k.tsp, the coordinates in TSPLIB format.
To match the points in the TSP data to the original astronomy databases, in the following file we list for each entry the corresponding Hipparcos or Tycho-2 ID, together with the xyz-coordinates used in the TSP model.
An optimal tour for star1k is given in the following files.
• star1k_tour.txt, a list of integers from 1 up to 1,000, giving the order the stars appear in the tour,
• star1k_order.txt, the points for star1k permuted in the tour order,
• star1k.tour, the tour in TSPLIB format.
To create an instance of the TSP, we need to specify precisely the point-to-point distances we use. For this we adopt the standard TSPLIB norm for 3D Euclidean data. This norm takes the straight-line distance between two points and rounds the resulting value to the nearest integer. In our case, the star-to-star distance is therefore measured to the nearest 1/10th parsec. Here is a simplified version of the computer code used in Concorde for the distance calculation.
Rotating -- See the point set rotating in 3-space. Stars are represented by twinkling points.