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15.5.18 astrf

astrf(coords [, equinox, /julian, /besselian] [, /fromequatorial, /fromecliptical, /fromgalactic] [, /toequatorial, /toecliptical, /togalactic])

Transforms between the main astronomical coordinate systems (with all coordinates measured in degrees). coords(0,/all) are longitudes or right ascensions. coords(1,/all) are latitudes or declinations. Where relevant, the coordinates are assumed to be or are returned relative to the indicated equinox, which is a Julian Date (if neither /julian nor /besselian is specified), or a Julian year (e.g., 2000.0 = J2000.0) if /julian is specified, or a Besselian year (e.g., 1875.0 = B1875.0) if /besselian is specified. Besselian years are taken to be 365.2421988 days long, and B1950.0 corresponds to JDE 2433282.4235. If equinox is not specified, then J2000.0 is assumed. The result has the same structure as coords. By default, /fromequatorial, /toecliptical is assumed.

See also: astron, precess