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Hoshi Stars星

The stars you can see without a telescope, with names, colours and distances; the 88 constellations with their lines and boundaries; the Messier objects; and seven map projections to draw them on.

Hoshi is the Japanese word 星 for a star. About the name

Contents

Reference · A constellation in 3D: its stars placed in space from their parallaxes, with the range each error allows and the Earth's lines of sight

Constellation3Dtype

A constellation's figure in space.

Import it

import type { Constellation3D } from "@johnmorrisdotca/hoshi-stars/constellation-3d";

Definition

interface Constellation3D {
    constellation: Constellation;
    viewpoint: {
        name: string | undefined;
        earth: Point3;
    };
    stars: StarIn3D[];
    segments: Array<[
        number,
        number
    ]>;
    counts: Record<DistanceQuality, number>;
    frame: {
        centre: Point3;
        up: Point3;
    };
    radius: number;
}

Members

NameTypeDescription
constellationConstellation

The constellation.

viewpoint{ name: string | undefined; earth: Point3; }

The viewpoint: its name where it is a star, and where the Earth is (earth), both relative to the viewpoint, which is the origin.

starsStarIn3D[]

The stars of the figure, each once, in the figure's order (the viewpoint star itself is left out).

segments[number, number][]

The lines of the figure as pairs of indexes into stars.

countsRecord<DistanceQuality, number>

How many stars have each quality of distance.

frame{ centre: Point3; up: Point3; }

The direction from the viewpoint to the middle of the figure, and the direction of "up" (celestial north, turned square to it): a unit vector each. From the middle of the figure looking along centre with up up, east is on the left, as on a sky chart.

radiusnumber

How far the figure's stars lie from centre, in degrees, at the most: the figure's angular radius.

Examples

import { constellationIn3D, type Constellation3D } from "@johnmorrisdotca/hoshi-stars/constellation-3d";

const orion: Constellation3D = constellationIn3D("Ori");
console.log(orion.stars.length, orion.segments.length, orion.counts);
8 8 { good: 0, fair: 1, rough: 6, none: 1 }

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/hoshi-stars 0.47.0.