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diff --git a/ast/pal/palRvgalc.c b/ast/pal/palRvgalc.c
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+/*
+*+
+*  Name:
+*     palRvgalc
+
+*  Purpose:
+*     Velocity component in a given direction due to the rotation
+*     of the Galaxy.
+
+*  Language:
+*     Starlink ANSI C
+
+*  Type of Module:
+*     Library routine
+
+*  Invocation:
+*     double palRvgalc( double r2000, double d2000 )
+
+*  Arguments:
+*     r2000 = double (Given)
+*        J2000.0 mean RA (radians)
+*     d2000 = double (Given)
+*        J2000.0 mean Dec (radians)
+
+*  Returned Value:
+*     Component of dynamical LSR motion in direction R2000,D2000 (km/s).
+
+*  Description:
+*     This function returns the Component of dynamical LSR motion in
+*     the direction of R2000,D2000. The result is +ve when the dynamical
+*     LSR is receding from the given point on the sky.
+*
+*  Notes:
+*     - The Local Standard of Rest used here is a point in the
+*     vicinity of the Sun which is in a circular orbit around
+*     the Galactic centre.  Sometimes called the "dynamical" LSR,
+*     it is not to be confused with a "kinematical" LSR, which
+*     is the mean standard of rest of star catalogues or stellar
+*     populations.
+*
+*  Reference:
+*     - The orbital speed of 220 km/s used here comes from Kerr &
+*     Lynden-Bell (1986), MNRAS, 221, p1023.
+
+*  Authors:
+*     PTW: Pat Wallace (STFC)
+*     DSB: David Berry (JAC, Hawaii)
+*     {enter_new_authors_here}
+
+*  History:
+*     2012-02-16 (DSB):
+*        Initial version.
+*        Adapted with permission from the Fortran SLALIB library.
+*     {enter_further_changes_here}
+
+*  Copyright:
+*     Copyright (C) 1995 Rutherford Appleton Laboratory
+*     Copyright (C) 2012 Science and Technology Facilities Council.
+*     All Rights Reserved.
+
+*  Licence:
+*     This program is free software: you can redistribute it and/or
+*     modify it under the terms of the GNU Lesser General Public
+*     License as published by the Free Software Foundation, either
+*     version 3 of the License, or (at your option) any later
+*     version.
+*
+*     This program is distributed in the hope that it will be useful,
+*     but WITHOUT ANY WARRANTY; without even the implied warranty of
+*     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+*     GNU Lesser General Public License for more details.
+*
+*     You should have received a copy of the GNU Lesser General
+*     License along with this program.  If not, see
+*     <http://www.gnu.org/licenses/>.
+
+*  Bugs:
+*     {note_any_bugs_here}
+*-
+*/
+
+#include "pal.h"
+#include "pal1sofa.h"
+
+double palRvgalc( double r2000, double d2000 ){
+
+/* Local Variables: */
+   double vb[ 3 ];
+
+/*
+*  LSR velocity due to Galactic rotation
+*
+*  Speed = 220 km/s
+*  Apex  = L2,B2  90deg, 0deg
+*        = RA,Dec  21 12 01.1  +48 19 47  J2000.0
+*
+*  This is expressed in the form of a J2000.0 x,y,z vector:
+*
+*      VA(1) = X = -SPEED*COS(RA)*COS(DEC)
+*      VA(2) = Y = -SPEED*SIN(RA)*COS(DEC)
+*      VA(3) = Z = -SPEED*SIN(DEC)
+*/
+
+   double va[ 3 ] = { -108.70408, +97.86251, -164.33610 };
+
+/* Convert given J2000 RA,Dec to x,y,z. */
+   eraS2c( r2000, d2000, vb );
+
+/* Compute dot product with LSR motion vector. */
+   return eraPdp( va, vb );
+}