solstice

Documentation

Overview

Solstice: Chapter 27: Equinoxes and Solstices.

Index

• func December(y int) float64
• func December2(y int, e *pp.V87Planet) float64
• func June(y int) float64
• func June2(y int, e *pp.V87Planet) float64
• func March(y int) float64
• func March2(y int, e *pp.V87Planet) float64
• func September(y int) float64
• func September2(y int, e *pp.V87Planet) float64

Examples

• June
• June2

Functions

func December

func December(y int) float64

December returns the JDE of the December solstice for a given year.

Results are valid for the years -1000 to +3000.

Accuracy is within one minute of time for the years 1951-2050.

func December2

func December2(y int, e *pp.V87Planet) float64

December2 returns a more accurate JDE of the December solstice.

Result is accurate to one second of time.

Parameter e must be a V87Planet object representing Earth, obtained with the package planetposition and code similar to

e, err := planetposition.LoadPlanet(planetposition.Earth, "")
    if err != nil {
        ....

See example under June2.

func June

func June(y int) float64

June returns the JDE of the June solstice for the given year.

Results are valid for the years -1000 to +3000.

Accuracy is within one minute of time for the years 1951-2050.

Example

package main

import (
	"fmt"

	"github.com/soniakeys/meeus/v3/solstice"
)

func main() {
	// Example 27.a, p. 180
	fmt.Printf("%.5f\n", solstice.June(1962))
}

Output:

2437837.39245

func June2

func June2(y int, e *pp.V87Planet) float64

June2 returns a more accurate JDE of the June solstice.

Result is accurate to one second of time.

Parameter e must be a V87Planet object representing Earth, obtained with the package planetposition.

Example

// Example 27.b, p. 180.
e, err := pp.LoadPlanet(pp.Earth)
if err != nil {
	fmt.Println(err)
	return
}
j := solstice.June2(1962, e)
t := j - 2437836.5 // 0h 1962 June 21
// result is VSOP87 result given in example 27.a, p. 180
fmt.Println(sexa.FmtTime(unit.TimeFromDay(t)))

Output:

21ʰ24ᵐ42ˢ

func March

func March(y int) float64

March returns the JDE of the March equinox for the given year.

Results are valid for the years -1000 to +3000.

Accuracy is within one minute of time for the years 1951-2050.

func March2

func March2(y int, e *pp.V87Planet) float64

March2 returns a more accurate JDE of the March equinox.

Result is accurate to one second of time.

Parameter e must be a V87Planet object representing Earth, obtained with the package planetposition and code similar to

e, err := planetposition.LoadPlanet(planetposition.Earth, "")
    if err != nil {
        ....

See example under June2.

func September

func September(y int) float64

September returns the JDE of the September equinox for the given year.

Results are valid for the years -1000 to +3000.

Accuracy is within one minute of time for the years 1951-2050.

func September2

func September2(y int, e *pp.V87Planet) float64

September2 returns a more accurate JDE of the September equinox.

Result is accurate to one second of time.

Parameter e must be a V87Planet object representing Earth, obtained with the package planetposition and code similar to

e, err := planetposition.LoadPlanet(planetposition.Earth, "")
    if err != nil {
        ....

See example under June2.