Class: Astronoby::Libration

Inherits:

Object

• Object
• Astronoby::Libration

Defined in:

lib/astronoby/libration.rb

Overview

Geocentric libration of the Moon: the small oscillations that let an observer on Earth see slightly more than half of the lunar surface over time. Holds the total (optical + physical) libration in longitude and latitude.

Instance Attribute Summary

• #latitude ⇒ Astronoby::Angle readonly

  Libration in latitude (b), positive towards the Moon’s north pole.

• #longitude ⇒ Astronoby::Angle readonly

  Libration in longitude (l), positive towards the Moon’s Mare Crisium (east limb).

Instance Method Summary

• #initialize(longitude:, latitude:) ⇒ Libration constructor

  A new instance of Libration.

Constructor Details

#initialize(longitude:, latitude:) ⇒ Libration

Returns a new instance of Libration.

Parameters:

• longitude (Astronoby::Angle) —

  libration in longitude

• latitude (Astronoby::Angle) —

  libration in latitude

# File 'lib/astronoby/libration.rb', line 19

def initialize(longitude:, latitude:)
  @longitude = longitude
  @latitude = latitude
  freeze
end

Instance Attribute Details

#latitude ⇒ Astronoby::Angle (readonly)

Returns libration in latitude (b), positive towards the Moon’s north pole.

Returns:

• (Astronoby::Angle) —

  libration in latitude (b), positive towards the Moon’s north pole

# File 'lib/astronoby/libration.rb', line 15

def latitude
  @latitude
end

#longitude ⇒ Astronoby::Angle (readonly)

Returns libration in longitude (l), positive towards the Moon’s Mare Crisium (east limb).

Returns:

• (Astronoby::Angle) —

  libration in longitude (l), positive towards the Moon’s Mare Crisium (east limb)

# File 'lib/astronoby/libration.rb', line 11

def longitude
  @longitude
end