From 40e5a5811c6ffce9b0974e93cdd927cbcf60c157 Mon Sep 17 00:00:00 2001 From: Joe Hunkeler Date: Tue, 11 Aug 2015 16:51:37 -0400 Subject: Repatch (from linux) of OSX IRAF --- math/slalib/doc/pa.hlp | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 math/slalib/doc/pa.hlp (limited to 'math/slalib/doc/pa.hlp') diff --git a/math/slalib/doc/pa.hlp b/math/slalib/doc/pa.hlp new file mode 100644 index 00000000..a7ee7357 --- /dev/null +++ b/math/slalib/doc/pa.hlp @@ -0,0 +1,36 @@ +.help pa Jun99 "Slalib Package" +.nf + + DOUBLE PRECISION FUNCTION slPA (HA, DEC, PHI) + + - - - + P A + - - - + + HA, Dec to Parallactic Angle (double precision) + + Given: + HA d hour angle in radians (geocentric apparent) + DEC d declination in radians (geocentric apparent) + PHI d observatory latitude in radians (geodetic) + + The result is in the range -pi to +pi + + Notes: + + 1) The parallactic angle at a point in the sky is the position + angle of the vertical, i.e. the angle between the direction to + the pole and to the zenith. In precise applications care must + be taken only to use geocentric apparent HA,Dec and to consider + separately the effects of atmospheric refraction and telescope + mount errors. + + 2) At the pole a zero result is returned. + + P.T.Wallace Starlink 16 August 1994 + + Copyright (C) 1995 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp -- cgit