@observerly/astrometry/dist/night.js

observerly's lightweight, zero-dependency, type safe astrometry library written in Typescript for calculating the position of celestial objects in the sky.

import { convertEquatorialToHorizontal as w } from "./coordinates.js";
import { g as C } from "./epoch-nmyjNjKp.js";
import { getCorrectionToHorizontalForRefraction as m } from "./refraction.js";
import { getSolarEquatorialCoordinate as J } from "./sun.js";
import { c as e, e as H } from "./utilities-BM-rBPno.js";
const R = (n, o) => {
  const { latitude: a, longitude: c } = o, l = C(n), r = Math.ceil(l - (2451545 + 9e-4) + 69.184 / 86400) - c / 360, t = (357.5291 + 0.98560028 * r) % 360, M = 1.9148 * Math.sin(e(t)) + 0.02 * Math.sin(e(2 * t)) + 3e-4 * Math.sin(e(3 * t)), h = (t + M + 180 + 102.9372) % 360, s = 2451545 + r + 53e-4 * Math.sin(e(t)) - 69e-4 * Math.sin(e(2 * h)), i = H(Math.asin(Math.sin(e(h)) * Math.sin(e(23.45)))), g = H(Math.acos(Math.sin(e(-0.833) - Math.sin(e(a)) * Math.sin(e(i))) / Math.cos(e(a)) * Math.cos(e(i)))), f = s - g / 360, D = s + g / 360;
  return {
    sunrise: new Date((f - 24405875e-1) * 86400 * 1e3),
    noon: new Date((s - 24405875e-1) * 86400 * 1e3),
    sunset: new Date((D - 24405875e-1) * 86400 * 1e3),
    J: r,
    ha: g
  };
}, T = (n, o, a = -12, c = 288.15, l = 101325) => {
  n = new Date(new Date(n.setHours(0, 0, 0, 0)).getTime());
  const { sunrise: u, noon: r, sunset: t } = R(n, o);
  if (u === null || t === null)
    return { sunrise: null, noon: null, sunset: null };
  let M = null;
  for (let s = -120; s <= 120; s++) {
    const i = new Date(u.getTime() + 6e4 * s), { ra: g, dec: f } = J(i), D = w(i, o, {
      ra: g,
      dec: f
    });
    if (m(D, c, l).alt > a && M === null) {
      M = i;
      break;
    }
  }
  let h = null;
  for (let s = -120; s <= 120; s++) {
    const i = new Date(t.getTime() + 6e4 * s), { ra: g, dec: f } = J(i), D = w(i, o, {
      ra: g,
      dec: f
    });
    if (m(D, c, l).alt < a && h === null) {
      h = i;
      break;
    }
  }
  return { sunrise: M || u, noon: r, sunset: h || t };
}, F = (n, o, a = -12, c = 288.15, l = 101325) => {
  const { sunset: u } = T(n, o, a, c, l), { sunrise: r } = T(new Date(n.getTime() + 6e4 * 60 * 24), o, a, c, l);
  return {
    start: u,
    end: r
  };
}, N = (n, o, a = -12, c = 288.15, l = 101325) => {
  const u = new Date(n.getFullYear(), n.getMonth(), n.getDate(), n.getHours(), n.getMinutes(), n.getSeconds(), n.getMilliseconds()), { sunrise: r, sunset: t } = T(n, o, a, c, l);
  return r === null || t === null ? !1 : u.getTime() <= r.getTime() || u.getTime() >= t.getTime();
};
export {
  R as getGeneralizedSolarTransit,
  F as getNight,
  T as getSolarTransit,
  N as isNight
};
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