Determines visibility of a celestial body relative to the Sun, as seen from the Earth. Returns information about the elongation angle and whether the body is best observed in the morning or evening.
Value
A list with the following elements:
- visibility
Integer flag indicating morning (0) or evening (1) visibility.
- elongation
The angle in degrees between the Earth-Sun and Earth-body vectors. Range: [0, 180].
- ecliptic_separation
The absolute difference in ecliptic longitude between the body and the Sun. Range: [0, 180].
- time
A POSIXct value representing the observation time.
- status
Status code from the underlying C function.
Examples
time <- as.POSIXct("2025-06-15 12:00:00", tz = "UTC")
astro_elongation(body = astro_body["MERCURY"], time = time)
#> $visibility
#> [1] 1
#>
#> $elongation
#> [1] 17.95865
#>
#> $ecliptic_separation
#> [1] 17.84749
#>
#> $time
#> [1] "2025-06-15 12:00:00 UTC"
#>
#> $status
#> [1] 0
#>