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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 · The faint stars: about 3 million of UCAC4's, to magnitude 12, in sky tiles loaded for the part of the sky you show

FaintStartype

One faint star.

Import it

import type { FaintStar } from "@johnmorrisdotca/hoshi-stars/faint";

Definition

interface FaintStar {
    rightAscension: number;
    declination: number;
    magnitude: number;
    colourIndex: number | undefined;
}

Members

NameTypeDescription
rightAscensionnumber

Right ascension in degrees at J2000 (the ICRS), 0 up to 360, good to a fraction of an arc-second.

declinationnumber

Declination in degrees at J2000, -90 to 90.

magnitudenumber

The magnitude to 0.05: APASS DR10's V for a bright star it holds (V 7.0 to 10.2, south of declination +20.0), else APASS V as UCAC4 carries it where it is APASS's own, else UCAC4's own model magnitude (between V and R). Smaller is brighter.

colourIndexnumber | undefined

B-V in magnitudes from APASS, to 0.0125, or undefined where UCAC4 has no APASS B and V for the star (about one star in ten).

Examples

import type { FaintStar } from "@johnmorrisdotca/hoshi-stars/faint";

const show = (star: FaintStar): string => `${star.magnitude.toFixed(2)} at ${star.rightAscension.toFixed(4)}, ${star.declination.toFixed(4)}`;
console.log(show({ rightAscension: 83.8, declination: -5.4, magnitude: 11.2, colourIndex: 0.7 }));
11.20 at 83.8000, -5.4000

What it prints (run when this page was built)

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