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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 · Map projections for sky charts

ProjectionOptionstype

How to place and size the chart.

Import it

import type { ProjectionOptions } from "@johnmorrisdotca/hoshi-stars/projection";

Definition

interface ProjectionOptions {
    centre: SkyPoint;
    scale?: number;
    rotation?: number;
    mirror?: boolean;
}

Members

NameTypeDescription
centreSkyPoint

The point of the sky that lands at (0, 0). With north up, it is the middle of the chart.

scale (optional)number | undefined

The radius of the celestial sphere in drawing units; default 1. stereographic puts 90 degrees from the centre at 2 times this, orthographic at exactly this. For equirectangular to give degrees, pass 180 / Math.PI.

rotation (optional)number | undefined

Turns the finished chart anticlockwise by this many degrees (as drawn with y up); default 0.

mirror (optional)boolean | undefined

True for the map convention, east to the right. Default false: the sky seen looking up, east to the left.

Examples

import type { ProjectionOptions } from "@johnmorrisdotca/hoshi-stars/projection";

const options: ProjectionOptions = { centre: { rightAscension: 83.8, declination: -5.4 }, scale: 300 };
console.log(options.scale);
300

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/hoshi-stars 0.7.0.