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diff --git a/math/slalib/doc/hfk5z.hlp b/math/slalib/doc/hfk5z.hlp new file mode 100644 index 00000000..a2bea786 --- /dev/null +++ b/math/slalib/doc/hfk5z.hlp @@ -0,0 +1,60 @@ +.help hfk5z Jun99 "Slalib Package" +.nf + + SUBROUTINE slHF5Z (RH,DH,EPOCH,R5,D5,DR5,DD5) + + - - - - - - + H F 5 Z + - - - - - - + + Transform a Hipparcos star position into FK5 J2000, assuming + zero Hipparcos proper motion. + + (double precision) + + Given: + RH d Hipparcos RA (radians) + DH d Hipparcos Dec (radians) + EPOCH d Julian epoch (TDB) + + Returned (all FK5, equinox J2000, epoch EPOCH): + R5 d RA (radians) + D5 d Dec (radians) + + Called: slDS2C, slDAVM, slDMXV, slDAVM, slDMXM, + slDIMV, slDVXV, slDC6S + + Notes: + + 1) The proper motion in RA is dRA/dt rather than cos(Dec)*dRA/dt. + + 2) The FK5 to Hipparcos transformation consists of a pure + rotation and spin; zonal errors in the FK5 catalogue are + not taken into account. + + 3) The published orientation and spin components are interpreted + as "axial vectors". An axial vector points at the pole of the + rotation and its length is the amount of rotation in radians. + + 4) It was the intention that Hipparcos should be a close + approximation to an inertial frame, so that distant objects + have zero proper motion; such objects have (in general) + non-zero proper motion in FK5, and this routine returns those + fictitious proper motions. + + 5) The position returned by this routine is in the FK5 J2000 + reference frame but at Julian epoch EPOCH. + + 6) See also slFK5H, slHFK5, slF5HZ. + + Reference: + + M.Feissel & F.Mignard, Astron. Astrophys. 331, L33-L36 (1998). + + P.T.Wallace Starlink 7 October 1998 + + Copyright (C) 1998 Rutherford Appleton Laboratory + Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. + +.fi +.endhelp |