Calculates the geocentric ecliptic coordinates of the Sun. The returned coordinates are based on the true equinox of date (the instantaneous intersection of the Earth's equatorial plane and the ecliptic plane at the given time).
Value
A list containing:
- elon
Ecliptic longitude in degrees.
- elat
Ecliptic latitude in degrees.
- vec
A list with Cartesian coordinates:
- x
X-coordinate in AU.
- y
Y-coordinate in AU.
- z
Z-coordinate in AU.
- t
Time as
POSIXct.
Details
This function accounts for light travel time from the Sun and corrects for precession and nutation of the Earth's axis.
Examples
time <- as.POSIXct("2025-03-20 09:00:00", tz = "UTC")
astro_sun_position(time)
#> $elon
#> [1] 359.999
#>
#> $elat
#> [1] 6.651003e-05
#>
#> $vec
#> $vec$x
#> [1] 0.995888
#>
#> $vec$y
#> [1] -1.734101e-05
#>
#> $vec$z
#> [1] 1.156046e-06
#>
#> $vec$t
#> [1] "2025-03-20 09:00:00 UTC"
#>
#>