`SkyBody`型

リファレンスの説明と例は英語です。見出しと目次は日本語です。

One body to draw over the stars: a planet, the Moon, a dwarf planet. Everything is given by the page (this package computes no positions).

phase is the lit fraction of the disc, 0 (new, dark) to 1 (full, or a planet with no visible phase). A body drawn as a disc (the Moon, always; any other whose disc is 4 pixels wide or more) shows it: the lit part is a crescent below 0.5 and gibbous above. brightLimb says on which side it is lit.

インポート

import type { SkyBody } from "@johnmorrisdotca/hoshi-stars/chart";

定義

interface SkyBody {
    id: string;
    names: SkyBodyNames;
    ra: number;
    dec: number;
    magnitude: number;
    phase: number;
    brightLimb?: number | undefined;
    size?: number | undefined;
}

メンバー

名前	型	説明
`id`	`string`	What a pick says it was (`hoshi-pick`'s `id`). The Moon is `moon`: it is drawn as a disc with its phase, a little larger than its true size so that the phase can be seen.
`names`	`SkyBodyNames`	The name written beside it, in English and in Japanese; the chart's language chooses.
`ra`	`number`	Where, in degrees: right ascension 0 to 360 and declination -90 to 90 (J2000, the frame the stars are in). A body whose number is not finite is not drawn.
`dec`	`number`
`magnitude`	`number`	The apparent visual magnitude (the Moon's is about -12.7 when full, Venus's about -4, Mars's 1.8 at its faintest). A body fainter than the chart's magnitude setting (5), made fainter by 2.5 for each tenfold of zoom as a telescope does, is left out.
`phase`	`number`	The lit fraction of the disc, 0 to 1. A value outside it is held to it; one that is not a number counts as 1 (full).
`brightLimb` (省略可)	`number \| undefined`	Where the lit side is: the position angle of the middle of the bright limb in degrees, measured from celestial north through east (the Almanac's convention; 90 is east, the side of the next star to rise). When left out, the lit side is the right of the chart.
`size` (省略可)	`number \| undefined`	The apparent diameter in arc-seconds. Left out, the body is a dot sized by its magnitude like a star; given, the disc is drawn at its true size where that is bigger than the dot.

例

import type { SkyBody } from "@johnmorrisdotca/hoshi-stars/chart";

const moon: SkyBody = { id: "moon", names: { en: "Moon", ja: "月" }, ra: 83.2, dec: 21.4, magnitude: -11.7, phase: 0.25, brightLimb: 250, size: 1860 };
console.log(moon.names.en, moon.phase);
// Moon 0.25

Moon 0.25

出力（このページを作ったときに実行した結果）

ソースを見る GitHub で編集@johnmorrisdotca/hoshi-stars 0.47.0 のソースから作成しました。

この日本語は、まだ日本語を母語とする方の確認を受けていません。訂正を歓迎します。

SkyBody型

定義

メンバー

例

`SkyBody`型