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author | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
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committer | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
commit | fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 (patch) | |
tree | bdda434976bc09c864f2e4fa6f16ba1952b1e555 /math/slalib/rvlsrd.f | |
download | iraf-linux-fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4.tar.gz |
Initial commit
Diffstat (limited to 'math/slalib/rvlsrd.f')
-rw-r--r-- | math/slalib/rvlsrd.f | 96 |
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diff --git a/math/slalib/rvlsrd.f b/math/slalib/rvlsrd.f new file mode 100644 index 00000000..720d6c9c --- /dev/null +++ b/math/slalib/rvlsrd.f @@ -0,0 +1,96 @@ + REAL FUNCTION slRVLD (R2000, D2000) +*+ +* - - - - - - - +* R V L D +* - - - - - - - +* +* Velocity component in a given direction due to the Sun's motion +* with respect to the dynamical Local Standard of Rest. +* +* (single precision) +* +* Given: +* R2000,D2000 r J2000.0 mean RA,Dec (radians) +* +* Result: +* Component of "peculiar" solar motion in direction R2000,D2000 (km/s) +* +* Sign convention: +* The result is +ve when the Sun is receding from the given point on +* the sky. +* +* Note: The Local Standard of Rest used here is the "dynamical" LSR, +* a point in the vicinity of the Sun which is in a circular +* orbit around the Galactic centre. The Sun's motion with +* respect to the dynamical LSR is called the "peculiar" solar +* motion. +* +* There is another type of LSR, called a "kinematical" LSR. A +* kinematical LSR is the mean standard of rest of specified star +* catalogues or stellar populations, and several slightly +* different kinematical LSRs are in use. The Sun's motion with +* respect to an agreed kinematical LSR is known as the "standard" +* solar motion. To obtain a radial velocity correction with +* respect to an adopted kinematical LSR use the routine slRVLK. +* +* Reference: Delhaye (1965), in "Stars and Stellar Systems", vol 5, +* p73. +* +* Called: +* slCS2C, slVDV +* +* P.T.Wallace Starlink 9 March 1994 +* +* Copyright (C) 1995 Rutherford Appleton Laboratory +* +* License: +* This program is free software; you can redistribute it and/or modify +* it under the terms of the GNU General Public License as published by +* the Free Software Foundation; either version 2 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 General Public License for more details. +* +* You should have received a copy of the GNU General Public License +* along with this program (see SLA_CONDITIONS); if not, write to the +* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, +* Boston, MA 02110-1301 USA +* +* Copyright (C) 1995 Association of Universities for Research in Astronomy Inc. +*- + + IMPLICIT NONE + + REAL R2000,D2000 + + REAL VA(3), VB(3) + + REAL slVDV + +* +* Peculiar solar motion from Delhaye 1965: in Galactic Cartesian +* coordinates (+9,+12,+7) km/s. This corresponds to about 16.6 km/s +* towards Galactic coordinates L2 = 53 deg, B2 = +25 deg, or RA,Dec +* 17 49 58.7 +28 07 04 J2000. +* +* The solar motion is expressed here in the form of a J2000.0 +* equatorial Cartesian vector: +* +* VA(1) = X = -SPEED*COS(RA)*COS(DEC) +* VA(2) = Y = -SPEED*SIN(RA)*COS(DEC) +* VA(3) = Z = -SPEED*SIN(DEC) + + DATA VA / +0.63823, +14.58542, -7.80116 / + + + +* Convert given J2000 RA,Dec to x,y,z + CALL slCS2C(R2000,D2000,VB) + +* Compute dot product with solar motion vector + slRVLD=slVDV(VA,VB) + + END |