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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 · What you can see tonight: the stars above the horizon of a place and a moment that the Sun's light, the sky's darkness and the air still let through, with the twilight, each star's altitude and azimuth and how easy it is to see

sunPositionfunction

The Sun's right ascension and declination of date, in degrees, from the Almanac's low-precision formula (0.01 degree from 1950 to 2050). No clock is read: the moment is passed in.

Import it

import { sunPosition } from "@johnmorrisdotca/hoshi-stars/tonight";

Definition

function sunPosition(when: When): { rightAscension: number; declination: number; }

Parameters

NameTypeDescription
whenWhen

The moment, a Date or milliseconds since 1970.

Returns

{ rightAscension: number; declination: number; }

{ rightAscension, declination } of the equinox of the date, in degrees.

Examples

import { sunPosition } from "@johnmorrisdotca/hoshi-stars/tonight";

// the June solstice: the Sun is as far north as it gets, 23.4 degrees
console.log(sunPosition(Date.UTC(2026, 5, 21, 8, 24)).declination.toFixed(1)); // 23.4
23.4

What it prints (run when this page was built)

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