feat: Added Transit type to transit module in @observerly/astrometry.

feat: Added Transit type to transit module in @observerly/astrometry.

src/transit.ts

@@ -26,6 +26,43 @@ export interface Parameters {
 
 /*****************************************************************************************************************/
 
+export interface  Transit {
+  /**
+   * 
+   * 
+   * The local sidereal time of rise.
+   * 
+   * 
+   */
+  LSTr: number
+  /**
+   * 
+   * 
+   * The local sidereal time of set.
+   * 
+   * 
+   */
+  LSTs: number
+  /**
+   * 
+   * 
+   * The azimuthal angle (in degrees) of the object at rise.
+   * 
+   * 
+   */
+  R: number
+  /**
+   * 
+   * 
+   * The azimuthal angle (in degrees) of the object at set.
+   * 
+   * 
+   */
+  S: number
+}
+
+/*****************************************************************************************************************/
+
 /**
  *
  * isBodyCircumpolar()
@@ -174,3 +211,46 @@ export const doesBodyRiseOrSet = (
 }
 
 /*****************************************************************************************************************/
+
+export const getTransit = (
+  observer: GeographicCoordinate,
+  target: EquatorialCoordinate,
+) => :
+  """
+  Determines the local sidereal time and azimuthal angle of rise and set for an object.
+
+  :param observer: The geographic coordinate of the observer.
+  :param target: The equatorial coordinate of the observed object.
+  :return either None when the object does not rise or set or the transit timings.
+  """
+  # Convert the right ascension to hours:
+  ra = target["ra"] / 15
+
+  # Get the transit parameters:
+  obj = get_does_object_rise_or_set(observer, target)
+
+  if not obj:
+      return None
+
+  H1 = obj["H1"]
+
+  H2 = degrees(acos(-H1)) / 15
+
+  # Get the azimuthal angle of rise:
+  R = degrees(acos(obj["Ar"]))
+
+  # Get the azimuthal angle of set:
+  S = 360 - R
+
+  # The local sidereal time of rise:
+  LSTr = 24 + ra - H2
+
+  if LSTr > 24:
+      LSTr -= 24
+
+  LSTs = ra + H2
+
+  if LSTs > 24:
+      LSTs -= 24
+
+  return {"LSTr": LSTr, "LSTs": LSTs, "R": R, "S": S}