starAccuracyfunction

How well each value of a star is known, and its grade. The grade is a rule on the stated figures, not a verdict on the star: A a distance known to under 5% and a modern position (an error, or where none is stated a resolution, of 2 arc-seconds or less), B a distance known to 20% or better, C anything else (a position and a rough distance, or no distance). A parallax with no stated error is never better than rough, except a dynamical one, which is fair. Sirius is grade A, Betelgeuse (a paper's distance, known to about 14%) is grade B and Rigel (a range of 590 to 1,480 light-years) is grade C.

import { starAccuracy } from "@johnmorrisdotca/hoshi-stars/accuracy";

function starAccuracy(star: Star | NearbyStar): StarAccuracy

import { starByName } from "@johnmorrisdotca/hoshi-stars";
import { starAccuracy } from "@johnmorrisdotca/hoshi-stars/accuracy";

const sirius = starAccuracy(starByName("Sirius")!);
console.log(sirius.grade, sirius.parallax.source, sirius.distance.quality, starAccuracy(starByName("Rigel")!).grade);

A GCTP good C