1 PRINT "From the November 1985 SKY & TELESCOPE, pp. 470-1."
2 PRINT
3 PRINT "This program calculates the 1950.0 rectangular coordinates of the"
4 PRINT "Sun."
5 PRINT
6 PRINT "INPUT:  Julian Day number (J), Julian Day fractional part (F)."
7 PRINT
8 PRINT "OUTPUT:  X, Y (directed along the celestial equator), Z (directed"
9 PRINT "         along the celestial poles) (AU)."
10 PRINT
500 REM    X,Y,Z OF THE SUN
501 REM    (EQUINOX 1950.0)
502 REM
503 INPUT "J,F ";J,F
504 J8=J-2415020!: R1=3.14159265#/180
505 T=(J8+F)/36525!
506 P0=1.396041+.000308*(T+.5)
507 P0=P0*(T-.499998)
508 A=100: GOSUB 529: G0=A+358.475833#
509 L0=A+279.696678#-P0
510 A=1336: GOSUB 529  
511 C0=A+270.434164#-P0
512 A=162: GOSUB 529  
513 V0=A+212.603219#
514 A=53: GOSUB 529: M0=A+319.529425#
515 A=8: GOSUB 529: J0=A+225.444651#
516 G=G0+T*(-.95025-.00015*T)
517 C=C0+T*(307.883142#-.001133*T)
518 L=L0+T*(.76892+.000303*T)
519 V=V0+T*(197.803875#+.001286*T)
520 M=M0+T*(59.8585+.000181*T)
521 J=J0+T*154.906654#
522 G=G*R1: C=C*R1: L=L*R1
523 V=V*R1: M=M*R1: J=J*R1
524 GOSUB 532  
525 PRINT "X: ";X
526 PRINT "Y: ";Y
527 PRINT "Z: ";Z
528 RUN "ASTRMENU.BAS"
529 REM   NORMALIZATION
530 A=360*(A*T-INT(A*T)): RETURN
531 REM
532 X=.000011*COS(2*G-L-2*J)
533 X=X+.000011*COS(2*G+L-2*V)
534 X=X-.000012*COS(G+L-V)
535 X=X-.000012*COS(4*G-L-8*M+3*J)
536 X=X+.000012*COS(4*G+L-8*M+3*J)
537 X=X-.000014*COS(C-2*L)
538 X=X+.000017*COS(C)
539 X=X+.000018*SIN(2*G+L-2*V)
540 X=X-.000021*T*COS(G+L)
541 X=X-.000026*SIN(G-L-J)
542 X=X+.000035*COS(2*G-L)
543 X=X+.000063*T*COS(G-L)
544 X=X+.000105*COS(2*G+L)
545 X=X+.008374*COS(G+L)
546 X=X-.025127*COS(G-L)
547 X=X+.99986*COS(L)
548 REM
549 Y=.00001*SIN(2*G+L-2*V)
550 Y=Y-.00001*SIN(2*G-L-2*J)
551 Y=Y-.000011*SIN(G+L-V)
552 Y=Y+.000011*SIN(4*G-L-8*M+3*J)
553 Y=Y+.000011*SIN(4*G+L-8*M+3*J)
554 Y=Y+.000013*SIN(C-2*L)
555 Y=Y+.000016*SIN(C)
556 Y=Y-.000017*COS(2*G+L-2*V)
557 Y=Y-.000019*T*SIN(G+L)
558 Y=Y-.000024*COS(G-L-J)
559 Y=Y-.000032*SIN(2*G-L)
560 Y=Y-.000057*T*SIN(G-L)
561 Y=Y+9.699999E-05*SIN(2*G+L)
562 Y=Y+.007683*SIN(G+L)
563 Y=Y+.023053*SIN(G-L)
564 Y=Y+.917308*SIN(L)
565 REM
566 Z=-.00001*COS(G-L-J)
567 Z=Z-.000014*SIN(2*G-L)
568 Z=Z-.000025*T*SIN(G-L)
569 Z=Z+.000042*SIN(2*G+L)
570 Z=Z+.003332*SIN(G+L)
571 Z=Z+.009998*SIN(G-L)
572 Z=Z+.397825*SIN(L)
573 RETURN