galpy.util.bovy_coords.pmrapmdec_to_pmllpmbb¶
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galpy.util.bovy_coords.
pmrapmdec_to_pmllpmbb
(pmra, pmdec, ra, dec, degree=False, epoch=2000.0)[source]¶ NAME:
pmrapmdec_to_pmllpmbbPURPOSE:
rotate proper motions in (ra,dec) into proper motions in (l,b)INPUT:
pmra - proper motion in ra (multplied with cos(dec)) [mas/yr]
pmdec - proper motion in dec [mas/yr]
ra - right ascension
dec - declination
degree - if True, ra and dec are given in degrees (default=False)
epoch - epoch of ra,dec (right now only 2000.0 and 1950.0 are supported when not using astropy’s transformations internally; when internally using astropy’s coordinate transformations, epoch can be None for ICRS, ‘JXXXX’ for FK5, and ‘BXXXX’ for FK4)
OUTPUT:
(pmll x cos(b),pmbb) for vector inputs [:,2]HISTORY:
2010-04-07 - Written - Bovy (NYU)
2014-06-14 - Re-written w/ numpy functions for speed and w/ decorators for beauty - Bovy (IAS)