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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 · How well each value of a star is known: the source and error of its position, magnitude, colour, parallax and proper motion, and a grade A, B or C

StarAccuracytype

Everything starAccuracy says of one star.

Import it

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

Definition

interface StarAccuracy {
    layer: "bright" | "nearby";
    grade: StarGrade;
    modernPosition: boolean;
    position: FieldAccuracy;
    magnitude: FieldAccuracy;
    colour: FieldAccuracy;
    parallax: FieldAccuracy;
    distance: DistanceAccuracy;
    properMotion: FieldAccuracy;
}

Members

NameTypeDescription
layer"nearby" | "bright"

The tier the star is from: bright (the 5,080, @johnmorrisdotca/hoshi-stars) or nearby (/nearby).

gradeStarGrade

The grade, by GRADE_RULES.

modernPositionboolean

Whether the position is modern by GRADE_RULES.modernPositionArcsec: the one thing that keeps a well-measured distance from grade A.

positionFieldAccuracy

The J2000 position, in arc-seconds.

magnitudeFieldAccuracy

The V magnitude, in magnitudes.

colourFieldAccuracy

The B-V colour index, in magnitudes. Only the bright tier has one.

parallaxFieldAccuracy

The parallax, in milliarcseconds.

distanceDistanceAccuracy

The distance the parallax makes.

properMotionFieldAccuracy

The proper motion, in milliarcseconds a year.

Examples

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

const sirius: StarAccuracy = starAccuracy(starByName("Sirius")!);
console.log(sirius.layer, sirius.grade);
bright A

What it prints (run when this page was built)

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