planetary

Documentation

Overview

Planetary: Chapter 36, The Calculation of some Planetary Phenomena.

Incomplete: Some functions unimplemented for lack of test data.

Index

• func JupiterConj(y float64) (jde float64)
• func JupiterOpp(y float64) (jde float64)
• func MarsOpp(y float64) (jde float64)
• func MarsStation2(y float64) (jde float64)
• func MercuryEastElongation(y float64) (jde float64, elongation unit.Angle)
• func MercuryInfConj(y float64) (jde float64)
• func MercurySupConj(y float64) (jde float64)
• func MercuryWestElongation(y float64) (jde float64, elongation unit.Angle)
• func NeptuneConj(y float64) (jde float64)
• func NeptuneOpp(y float64) (jde float64)
• func SaturnConj(y float64) (jde float64)
• func SaturnOpp(y float64) (jde float64)
• func UranusConj(y float64) (jde float64)
• func UranusOpp(y float64) (jde float64)
• func VenusInfConj(y float64) (jde float64)

Examples

• MarsStation2
• MercuryInfConj
• MercuryWestElongation
• SaturnConj

Functions

func JupiterConj

func JupiterConj(y float64) (jde float64)

JupiterConj returns the time of an conjunction of Jupiter. 计算木星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func JupiterOpp

func JupiterOpp(y float64) (jde float64)

JupiterOpp returns the time of an opposition of Jupiter. 计算木星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func MarsOpp

func MarsOpp(y float64) (jde float64)

MarsOpp returns the time of an opposition of Mars. 计算火星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func MarsStation2

func MarsStation2(y float64) (jde float64)

Example

package main

import (
	"fmt"
	"math"
	"time"

	"github.com/mooncaker816/learnmeeus/v3/julian"
	"github.com/mooncaker816/learnmeeus/v3/planetary"
)

func main() {
	// Example 36.d, p. 254
	j := planetary.MarsStation2(1997.3)
	fmt.Printf("%.3f\n", j)
	y, m, df := julian.JDToCalendar(j)
	d, f := math.Modf(df)
	fmt.Printf("%d %s %d, at %dʰ\n", y, time.Month(m), int(d), int(f*24+.5))
}

Output:

2450566.255
1997 April 27, at 18ʰ

func MercuryEastElongation

func MercuryEastElongation(y float64) (jde float64, elongation unit.Angle)

MercuryEastElongation returns the time and elongation of a greatest eastern elongation of Mercury. 水星最大东角距

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func MercuryInfConj

func MercuryInfConj(y float64) (jde float64)

MercuryInfConj returns the time of an inferior conjunction of Mercury. 计算水星的下合日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

Example

package main

import (
	"fmt"
	"math"
	"time"

	"github.com/mooncaker816/learnmeeus/v3/julian"
	"github.com/mooncaker816/learnmeeus/v3/planetary"
)

func main() {
	// Example 36.a, p. 252
	j := planetary.MercuryInfConj(1993.75)
	fmt.Printf("%.3f\n", j)
	y, m, df := julian.JDToCalendar(j)
	d, f := math.Modf(df)
	fmt.Printf("%d %s %d, at %dʰ\n", y, time.Month(m), int(d), int(f*24+.5))
}

Output:

2449297.645
1993 November 6, at 3ʰ

func MercurySupConj

func MercurySupConj(y float64) (jde float64)

MercurySupConj returns the time of a superior conjunction of Mercury. 计算水星的上合日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func MercuryWestElongation

func MercuryWestElongation(y float64) (jde float64, elongation unit.Angle)

MercuryWestElongation returns the time and elongation of a greatest western elongation of Mercury. 水星最大西角距

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

Example

// Example 36.c, p. 253
j, e := planetary.MercuryWestElongation(1993.9)
fmt.Printf("%.2f\n", j)
y, m, df := julian.JDToCalendar(j)
d, f := math.Modf(df)
fmt.Printf("%d %s %d, at %dʰ\n", y, time.Month(m), int(d), int(f*24+.5))
fmt.Printf("%.4f deg\n", e.Deg())
fmt.Printf("%m\n", sexa.FmtAngle(e))

Output:

2449314.14
1993 November 22, at 15ʰ
19.7506 deg
19°45′

func NeptuneConj

func NeptuneConj(y float64) (jde float64)

NeptuneConj returns the time of an conjunction of Neptune. 计算海王星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func NeptuneOpp

func NeptuneOpp(y float64) (jde float64)

NeptuneOpp returns the time of an opposition of Neptune. 计算海王星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func SaturnConj

func SaturnConj(y float64) (jde float64)

SaturnConj returns the time of a conjunction of Saturn. 计算土星的合日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

Example

package main

import (
	"fmt"
	"math"
	"time"

	"github.com/mooncaker816/learnmeeus/v3/julian"
	"github.com/mooncaker816/learnmeeus/v3/planetary"
)

func main() {
	// Example 36.b, p. 252
	j := planetary.SaturnConj(2125.5)
	fmt.Printf("%.3f\n", j)
	y, m, df := julian.JDToCalendar(j)
	d, f := math.Modf(df)
	fmt.Printf("%d %s %d, at %dʰ\n", y, time.Month(m), int(d), int(f*24+.5))
}

Output:

2497437.904
2125 August 26, at 10ʰ

func SaturnOpp

func SaturnOpp(y float64) (jde float64)

SaturnOpp returns the time of an opposition of Saturn. 计算土星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func UranusConj

func UranusConj(y float64) (jde float64)

UranusConj returns the time of an conjunction of Uranus. 计算天王星的合日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func UranusOpp

func UranusOpp(y float64) (jde float64)

UranusOpp returns the time of an opposition of Uranus. 计算天王星的冲日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)

func VenusInfConj

func VenusInfConj(y float64) (jde float64)

VenusInfConj returns the time of an inferior conjunction of Venus. 计算金星的下合日

Result is time (as a jde) of the event nearest the given time (as a decimal year.)