19 Aquarii must be rotating at least that fast. 19 Aquarii 19 Aquarii is a star in the constellation of Aquarius. With an apparent magnitude of about 5.7, the star is barely visible to the naked eye (see Bortle scale). Parallax estimates made by the Hipparcos spacecraft put it at a distance of about 300 light years (92 parsecs) away from the Earth. 19 Aquarii has a spectral type of A8V, meaning it is an A-type main-sequence star. These types of stars are bluish-white colored, and have effective temperatures between 7100 and 11500 K. It rotates fairly fast, as its projected rotational
Unit distance graph way (up to congruence) to place the vertices at distinct locations such that adjacent vertices are a unit distance apart, and this placement also puts the two endpoints of the missing spoke at unit distance . posed the problem of estimating how many pairs of points in a set of "n" points could be at unit distance from each other. In graph theoretic terms, how dense can a unit distance graph be? The hypercube graph provides a lower bound on the number of unit distances proportional to formula_1 By considering points in a square grid with carefully chosen spacing, Erdős