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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 whole sky on one wide 2:1 map: galactic or equatorial, Mollweide, Hammer or plate carrée, with lines cut cleanly at the seam

allSkyUnprojectfunction

The sky under a point of the picture: the inverse of allSkyProject, with the same options.

Import it

import { allSkyUnproject } from "@johnmorrisdotca/hoshi-stars/all-sky";

Definition

function allSkyUnproject(point: AllSkyPoint, options: AllSkyOptions): SkyPoint | undefined

Parameters

NameTypeDescription
pointAllSkyPoint

A point of the picture, x from the left and y from the top.

optionsAllSkyOptions

The same options that drew the picture.

Returns

SkyPoint | undefined

The sky position (right ascension 0 up to 360 and declination, in degrees, J2000), or undefined when the point is outside the oval (or the box, for the plain rectangle).

Examples

import { allSkyProject, allSkyUnproject } from "@johnmorrisdotca/hoshi-stars/all-sky";

const options = { width: 1000, frame: "equatorial" } as const;
const spot = allSkyProject({ rightAscension: 88.79, declination: 7.41 }, options); // Betelgeuse
console.log(allSkyUnproject(spot, options)); // about { rightAscension: 88.79, declination: 7.41 }
{ rightAscension: 88.79000000000002, declination: 7.409999999999998 }

What it prints (run when this page was built)

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