sunpy.coordinates.get_sun_L0(time='now')[source] [edit on github]

Return the L0 angle for the Sun at a specified time, which is the Carrington longitude of the Sun-disk center as seen from Earth.


Due to apparent disagreement between published references, the returned L0 may be inaccurate by up to ~2 arcmin, which translates in the worst case to a shift of ~0.5 arcsec in helioprojective coordinates for an observer at 1 AU. Until this is resolved, be cautious with analysis that depends critically on absolute (as opposed to relative) values of Carrington longitude.

Parameters:time (various) – Time to use as Time or in a parse_time-compatible format
Returns:out (Longitude) – The Carrington longitude