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HyperLEDA documentation: parameter: pa

Position angle on the sky of the apparent major axis: pa

pa is the position angle of the major axis of the isophote 25 mag/arcsec**2 in the B-band for galaxies. It is counted from the North (pa=0) toward East between 0 and 180.

The position angle is defined in the B1950 coordinate system, but the differences introduced by the precession are generally within the precision of the measurements.

The length of the major axis is defined in the parameter logd25, and the axis ratio in the parameter logr25.

pa is available for 894383 objects (May 2003 version of the database).

HyperLeda

Questions: prugniel@obs.univ-lyon1.fr