Skip to the content

Wakusei Planets惑星

The Sun, the planets and their moons as a clean line drawing, a shaded realistic drawing or a painted surface map, with real sizes, tilt and rotation, and the moons where they are at any date and time.

Wakusei is the Japanese word 惑星 for a planet. About the name

Contents

Reference · Julian dates (and the julian package's functions), calendars, time scales, sidereal time and Mars time

equationOfTheEquinoxesfunction

The equation of the equinoxes in degrees: the nutation in longitude times the cosine of the obliquity, what apparent sidereal time has over mean (about 1 second of time at most).

Import it

import { equationOfTheEquinoxes } from "@johnmorrisdotca/wakusei-planets/time";

Definition

function equationOfTheEquinoxes(when: When): number

Parameters

NameTypeDescription
whenWhen

A Date or milliseconds since 1970 (UTC).

Returns

number

Degrees, between about -0.0013 and 0.0013.

Examples

import { equationOfTheEquinoxes } from "@johnmorrisdotca/wakusei-planets/time";

console.log((equationOfTheEquinoxes(Date.UTC(1987, 3, 10)) * 240).toFixed(4));
-0.2363

What it prints (run when this page was built)

View sourceEdit on GitHubMade from the source of @johnmorrisdotca/wakusei-planets 0.24.0.