planet: Compute coordinates of a planet in solar system.

In moonsun: Basic astronomical calculations with R

Description

This function computes equatorial coordinates for inner or outer planet for given Julian Day Number.

Usage

planet(jday = jd(), name = "", inner = FALSE, tp, ep, oo, e, a, i, om, th, mag)

Arguments

jday	Julian Day Number, default today
name	name of a planet (appended to dates in result)
inner	TRUE if it is inner, FALSE if outer planet
tp	period of a planet (tropical years)
ep	longitude at epoch 1990 January 0.00 (degrees)
oo	longitude of the perihelion (degrees)
e	eccentricity of the orbit
a	semi-major axis of the orbit (AU)
i	inclination of the orbit (degrees)
om	longitude of the ascending node (degrees)
th	angular diameter at 1 AU (arcsecs)
mag	visual magnitude at 1 AU

Details

The algorithm used here is fairly simple, it does not consider the Kepler equation, nor gravitational influences from other planets. See sun() for details.

This function is not called by user unless calculating a position for planetoid or modified data. The planets() function calls it with appropriate parameters automatically.

Value

An object of class eqc, containing position and other data for requested days, see planets() for details.

Author(s)

Lukasz Komsta

Examples

planets()

Example output

                            ra             d phase  angle  dist size  mag    
2019-11-23-Sun     15h 53m  3s -21* 45' 26''    NA     NA  0.99  0.5   NA Sco
2019-11-23-Moon    12h 42m 43s  -5* 30' 13''  17.1  113.1  0.95 32.7   NA Vir
2019-11-23-Mercury 14h 41m 22s -14* 52'  2''  36.1  114.9  0.85  7.9 -2.1 Lib
2019-11-23-Venus   17h 41m 47s -25* 25' 35''  90.3  -85.7  1.47 11.5 -4.1 Sgr
2019-11-23-Mars    13h 58m 33s -12* 39'  6''  97.9  111.5  2.43  3.9  1.5 Vir
2019-11-23-Jupiter 17h 48m 30s -24* 44' 27''  99.8  -89.2  6.10 32.3 -1.9 Sgr
2019-11-23-Saturn  19h 11m 56s -23* 42' 23''  99.9  -97.2 10.71 15.5  1.3 Sgr
2019-11-23-Uranus   2h  7m 53s  12* 23' 38'' 100.0 -110.7 18.96  3.5  5.7 Ari
2019-11-23-Neptune 23h  6m  4s  -7*  6' 49'' 100.0 -113.0 29.71  2.1  7.9 Aqr
2019-11-23-Pluto   18h 54m  6s -21*  3' 43'' 100.0  -97.4 33.56  0.2 14.2 Sgr
There were 19 warnings (use warnings() to see them)

moonsun documentation built on May 29, 2017, 12:17 p.m.