astronomy-js/lib/constants.js

A lightweight javascript library for astronomical calculations.

export const Constants = {
  SOLAR_SYSTEM_OBJECT: "SOLAR_SYSTEM_OBJECT",
  GREENWICH_OBSERVATORY_COORDINATES: {
    LATITUDE: 51.476852,
    LONGITUDE: -0.0005,
    RADIUS: 6371000 + 46,
  },
  KIRUNA_COORDINATES: {
    LATITUDE: 67.85,
    LONGITUDE: 20.21,
    RADIUS: 6371000 + 500,
  },
  EPHEMERIS_TYPE: {
    RISE: {
      NAME: "RISE",
      ALTITUDE: "-0.833",
      IS_GOING_UP: true,
    },
    SET: {
      NAME: "SET",
      ALTITUDE: "-0.833",
      IS_GOING_UP: false,
    },
    TRANSIT: {
      NAME: "TRANSIT",
      ALTITUDE: null,
      IS_GOING_UP: null,
    },
    CIVIL_TWILIGHT_START: {
      NAME: "CIVIL_TWILIGHT_START",
      ALTITUDE: "-6",
      IS_GOING_UP: true,
    },
    CIVIL_TWILIGHT_END: {
      NAME: "CIVIL_TWILIGHT_END",
      ALTITUDE: "-6",
      IS_GOING_UP: false,
    },
    NAUTICAL_TWILIGHT_START: {
      NAME: "NAUTICAL_TWILIGHT_START",
      ALTITUDE: "-12",
      IS_GOING_UP: true,
    },
    NAUTICAL_TWILIGHT_END: {
      NAME: "NAUTICAL_TWILIGHT_END",
      ALTITUDE: "-12",
      IS_GOING_UP: false,
    },
    ASTRONOMICAL_TWILIGHT_START: {
      NAME: "ASTRONOMICAL_TWILIGHT_START",
      ALTITUDE: "-18",
      IS_GOING_UP: true,
    },
    ASTRONOMICAL_TWILIGHT_END: {
      NAME: "ASTRONOMICAL_TWILIGHT_END",
      ALTITUDE: "-18",
      IS_GOING_UP: false,
    },
  },
  MS_PER_HOUR: 3600 * 1000,
  MS_PER_DAY: 3600 * 1000 * 24,
  MS_PER_YEAR: 3600 * 1000 * 24 * 365.2422,
  JULIAN_DAY_OFFSET: 2440587.5,
  JULIAN_DAY_2000: 2451545,
  JULIAN_DAY_2010: 2451545 + 3652.5,
  EPS: Math.pow(10, -9),
  DEGREE: Math.PI / 180,
  NUMBERS_OF_ATTEMPT_TO_GET_POSITIONAL_EPHEMERIS: 5,
  ARC_SECONDS_IN_A_DEGREE: 3600,
  DAYS_PER_JULIAN_CENTURY: 36525,
};