Merge pull request #407 from observerly/refactor/abberation/getCorrectionToEquatorialForAnnualAbberation

refactor!: amend to getCorrectionToEquatorialForAnnualAbberation usage in abberation module in @observerly/astrometry

Author: michealroberts

src/abberation.ts

@@ -15,19 +15,19 @@ import { getEccentricityOfOrbit } from './earth'
 import { getJulianDate } from './epoch'
 
 import {
-    getLunarMeanEclipticLongitudeOfTheAscendingNode,
-    getLunarMeanGeometricLongitude
+  getLunarMeanEclipticLongitudeOfTheAscendingNode,
+  getLunarMeanGeometricLongitude
 } from './moon'
 
 import { getSolarMeanGeometricLongitude, getSolarTrueGeometricLongitude } from './sun'
 
-import { convertDegreesToRadians as radians } from './utilities'
+import { convertRadiansToDegrees as degrees, convertDegreesToRadians as radians } from './utilities'
 
 /*****************************************************************************************************************/
 
 /**
  *
- * getCorrectionToEquatorialForAbberation()
+ * getCorrectionToEquatorialForAnnualAbberation()
  *
  * Corrects the equatorial coordinate of a target for abberation in
  * longitude and obliquity due to the apparent motion of the Earth.
@@ -37,7 +37,7 @@ import { convertDegreesToRadians as radians } from './utilities'
  * @returns The corrected equatorial coordinate of the target.
  *
  */
-export const getCorrectionToEquatorialForAbberation = (
+export const getCorrectionToEquatorialForAnnualAbberation = (
   datetime: Date,
   target: EquatorialCoordinate
 ): EquatorialCoordinate => {
@@ -71,7 +71,7 @@ export const getCorrectionToEquatorialForAbberation = (
   const ε = radians(getObliquityOfTheEcliptic(datetime) + Δε / 3600)
 
   // Get the constant of abberation (in degrees):
-  const κ = 20.49552
+  const κ = radians(20.49552 / 3600)
 
   // Get the eccentricity of the Earth's orbit (dimensionless):
   const e = getEccentricityOfOrbit(datetime)
@@ -100,8 +100,8 @@ export const getCorrectionToEquatorialForAbberation = (
         Math.cos(ra) * Math.sin(dec) * Math.sin(ϖ))
 
   return {
-    ra: Δra / 3600,
-    dec: Δdec / 3600
+    ra: degrees(Δra),
+    dec: degrees(Δdec)
   }
 }
 

src/observation.ts

@@ -6,7 +6,7 @@
 
 /*****************************************************************************************************************/
 
-import { getCorrectionToEquatorialForAbberation } from './abberation'
+import { getCorrectionToEquatorialForAnnualAbberation } from './abberation'
 
 import { getHourAngle } from './astrometry'
 
@@ -58,7 +58,10 @@ export class Observation extends Object {
 
   public latitude = Number.NEGATIVE_INFINITY
 
-  constructor({ ra = Number.NEGATIVE_INFINITY, dec = Number.NEGATIVE_INFINITY }: EquatorialCoordinate, observer?: Observer) {
+  constructor(
+    { ra = Number.NEGATIVE_INFINITY, dec = Number.NEGATIVE_INFINITY }: EquatorialCoordinate,
+    observer?: Observer
+  ) {
     super()
 
     const { datetime, longitude, latitude } = observer || {
@@ -138,7 +141,7 @@ export class Observation extends Object {
   }
 
   private setEquatorialCoordinates(target: EquatorialCoordinate) {
-    const abberation = getCorrectionToEquatorialForAbberation(this.datetime, target)
+    const abberation = getCorrectionToEquatorialForAnnualAbberation(this.datetime, target)
 
     const nutation = getCorrectionToEquatorialForNutation(this.datetime, target)
 

src/q.ts

@@ -6,7 +6,7 @@
 
 /*****************************************************************************************************************/
 
-import { getCorrectionToEquatorialForAbberation } from './abberation'
+import { getCorrectionToEquatorialForAnnualAbberation } from './abberation'
 
 import { getAngularSeparation } from './astrometry'
 
@@ -136,7 +136,7 @@ export function getQIndex(
   const precession = getCorrectionToEquatorialForPrecessionOfEquinoxes(datetime, target)
 
   // Get the correction to the target's equatorial coordinates for abberation:
-  const abberation = getCorrectionToEquatorialForAbberation(datetime, target)
+  const abberation = getCorrectionToEquatorialForAnnualAbberation(datetime, target)
 
   // Get the correction to the target's equatorial coordinates for nutation:
   const nutation = getCorrectionToEquatorialForNutation(datetime, target)

tests/abberation.spec.ts

@@ -10,7 +10,7 @@ import { describe, expect, it } from 'vitest'
 
 /*****************************************************************************************************************/
 
-import { type EquatorialCoordinate, getCorrectionToEquatorialForAbberation } from '../src'
+import { type EquatorialCoordinate, getCorrectionToEquatorialForAnnualAbberation } from '../src'
 
 /*****************************************************************************************************************/
 
@@ -29,13 +29,13 @@ const betelgeuse: EquatorialCoordinate = { ra: 88.7929583, dec: 7.4070639 }
 
 /*****************************************************************************************************************/
 
-describe('getCorrectionToEquatorialForAbberation', () => {
+describe('getCorrectionToEquatorialForAnnualAbberation', () => {
   it('should be defined', () => {
-    expect(getCorrectionToEquatorialForAbberation).toBeDefined()
+    expect(getCorrectionToEquatorialForAnnualAbberation).toBeDefined()
   })
 
   it('should return the correct abberation correction for the J2000 default epoch', () => {
-    const { ra, dec } = getCorrectionToEquatorialForAbberation(
+    const { ra, dec } = getCorrectionToEquatorialForAnnualAbberation(
       new Date('2000-01-01T00:00:00+00:00'),
       betelgeuse
     )
@@ -44,7 +44,7 @@ describe('getCorrectionToEquatorialForAbberation', () => {
   })
 
   it('should return the correct abberation correction for the designated epoch', () => {
-    const { ra, dec } = getCorrectionToEquatorialForAbberation(datetime, betelgeuse)
+    const { ra, dec } = getCorrectionToEquatorialForAnnualAbberation(datetime, betelgeuse)
     expect(ra + betelgeuse.ra).toBe(88.78837512114575)
     expect(dec + betelgeuse.dec).toBe(7.406109156062398)
   })