Class Moon

Calculates the moon's sky position at a given time. When instantiated, the class members are set to the sky position of the moon at the given time. The calculation is done using libnova's ln_get_lunar_equ_coords. A different time can be provided by the user. The sky coordinates are stored together with the time. A function is provided to convert the moon's position to celestial coordinates. A function to calculate the illuminated fraction of the moon's disk.
Defined in: Moon.js.

Class Summary
Constructor Attributes	Constructor Name and Description
	Moon(time)

Field Summary
Field Attributes	Field Name and Description
<constant>	dec Declination of the moon in degrees.
<constant>	ra Right ascension of the moon in hours.
<constant>	time Time corresponding to the calculated sky coordinates of the moon.

Method Summary
Method Attributes	Method Name and Description
<static>	Moon.disk(time) Calculates the illuminated fraction of the moon's disk.
<static>	Moon.horizon(time) Calculate moon rise, set and transit times.
	toLocal() Converts the moon's sky coordinates to celestial coordinates.

Class Detail

Moon(time)

Author: Thomas Bretz.

   var moon = new Moon();
   var local = moon.toLocal();

Parameters:
{Date} time Optional, Default: new Date(): Reference time for the calculation of the moon's position.

Field Detail

<constant> {Number} dec

Declination of the moon in degrees.

<constant> {Number} ra

Right ascension of the moon in hours.

<constant> {Date} time

Time corresponding to the calculated sky coordinates of the moon.

Method Detail

<static> {Number} Moon.disk(time)

Calculates the illuminated fraction of the moon's disk. Calculates the illuminated fraction of the moon's disk for the provided time. If no time is provided, the current system time is used. The calculation is done using libnova's ln_get_lunar_disk.

Parameters:
{Date} time Optional, Default: new Date(): Time for which the moon disk should be calculated. If no time is given, the current time is used.

Returns:: The illuminated fraction of the moon's disk corresponding to the time argument

<static> Moon.horizon(time)

Calculate moon rise, set and transit times. Calculates the moon rise and set time, above and below horizon, and the time of culmination (transit time) for the given time. The calculation is done using libnova's ln_get_lunar_rst and is always performed for the FACT site at La Palma.

   var date = new Date("2012-10-25 16:30 GMT"); // Date in UTC
   console.out(JSON.stringify(Moon.horizon(date));

Parameters:
{Date} time Optional, Default: new Date(): Date for which the times should be calculated. Note that the date is converted to UTC and the times are calculated such that the Date (yy/mm/dd) is identical for all returned values.

Returns:: An object with the following properties is returned: time {Date} the provided time; rise, transit, set {Date} times of rise, set and transit; isUp {Boolean} whether the moon is above or below horizon at the provided time. If the moon does not rise or set, the properties rise, transit and set will be undefined.

{Local} toLocal()

Converts the moon's sky coordinates to celestial coordinates. As observatory location the FACT telescope is assumed. For the time, the time corresponding to the stored sky coordinates is used. The conversion is done using libnova's ln_get_hrz_from_equ.

Returns:: {Local} A Local object with the converted coordinates and the corresponding time.

Classes

Class Moon