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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 big a Messier object is on the sky and which way it lies, and its outline

DeepSkyShapetype

How big a deep-sky object is on the sky and which way it lies. Each part is a measurement or it is undefined: nothing is guessed. Where the minor axis or the angle is missing, the object is known to be at least that large and no more.

Import it

import type { DeepSkyShape } from "@johnmorrisdotca/hoshi-stars/deep-sky/shape";

Also exported from: @johnmorrisdotca/hoshi-stars/deep-sky/ngc-ic-shape

Definition

interface DeepSkyShape {
    majorArcmin: number | undefined;
    minorArcmin: number | undefined;
    positionAngle: number | undefined;
    source: DeepSkyShapeSource | undefined;
}

Members

NameTypeDescription
majorArcminnumber | undefined

The longest way across, in arc-minutes, or undefined where no catalogue gives one.

minorArcminnumber | undefined

The shortest way across, in arc-minutes, or undefined where it is not measured (then the object is drawn round, at the major diameter).

positionAnglenumber | undefined

The angle of the major axis in degrees, 0 up to 180, measured from north through east (90 is east-west), or undefined where it is not measured.

sourceDeepSkyShapeSource | undefined

The catalogue of the major axis, or undefined with it.

Examples

import { deepSkyShape } from "@johnmorrisdotca/hoshi-stars/deep-sky/shape";
import { deepSkyObject } from "@johnmorrisdotca/hoshi-stars/deep-sky";

const shape = deepSkyShape(deepSkyObject("M31")!);
console.log(shape.majorArcmin, shape.minorArcmin, shape.positionAngle, shape.source);
190.5 61.7 35 RC3

What it prints (run when this page was built)

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