| #include "astro.h" |
| |
| |
| void |
| venus(void) |
| { |
| double pturbl, pturbb, pturbr; |
| double lograd; |
| double dele, enom, vnom, nd, sl; |
| double v0, t0, m0, j0, s0; |
| double lsun, elong, ci, dlong; |
| |
| /* |
| * here are the mean orbital elements |
| */ |
| |
| ecc = .00682069 - .00004774*capt + 0.091e-6*capt2; |
| incl = 3.393631 + .0010058*capt - 0.97e-6*capt2; |
| node = 75.779647 + .89985*capt + .00041*capt2; |
| argp = 130.163833 + 1.408036*capt - .0009763*capt2; |
| mrad = .7233316; |
| anom = 212.603219 + 1.6021301540*eday + .00128605*capt2; |
| motion = 1.6021687039; |
| |
| /* |
| * mean anomalies of perturbing planets |
| */ |
| |
| v0 = 212.60 + 1.602130154*eday; |
| t0 = 358.63 + .985608747*eday; |
| m0 = 319.74 + 0.524032490*eday; |
| j0 = 225.43 + .083090842*eday; |
| s0 = 175.8 + .033459258*eday; |
| |
| v0 *= radian; |
| t0 *= radian; |
| m0 *= radian; |
| j0 *= radian; |
| s0 *= radian; |
| |
| incl *= radian; |
| node *= radian; |
| argp *= radian; |
| anom = fmod(anom, 360.)*radian; |
| |
| /* |
| * computation of long period terms affecting the mean anomaly |
| */ |
| |
| anom += |
| (2.761-0.022*capt)*radsec*sin( |
| 13.*t0 - 8.*v0 + 43.83*radian + 4.52*radian*capt) |
| + 0.268*radsec*cos(4.*m0 - 7.*t0 + 3.*v0) |
| + 0.019*radsec*sin(4.*m0 - 7.*t0 + 3.*v0) |
| - 0.208*radsec*sin(s0 + 1.4*radian*capt); |
| |
| /* |
| * computation of elliptic orbit |
| */ |
| |
| enom = anom + ecc*sin(anom); |
| do { |
| dele = (anom - enom + ecc * sin(enom)) / |
| (1 - ecc*cos(enom)); |
| enom += dele; |
| } while(fabs(dele) > converge); |
| vnom = 2*atan2(sqrt((1+ecc)/(1-ecc))*sin(enom/2), |
| cos(enom/2)); |
| rad = mrad*(1 - ecc*cos(enom)); |
| |
| lambda = vnom + argp; |
| |
| /* |
| * perturbations in longitude |
| */ |
| |
| icosadd(venfp, vencp); |
| pturbl = cosadd(4, v0, t0, m0, j0); |
| pturbl *= radsec; |
| |
| /* |
| * perturbations in latidude |
| */ |
| |
| pturbb = cosadd(3, v0, t0, j0); |
| pturbb *= radsec; |
| |
| /* |
| * perturbations in log radius vector |
| */ |
| |
| pturbr = cosadd(4, v0, t0, m0, j0); |
| |
| /* |
| * reduction to the ecliptic |
| */ |
| |
| lambda += pturbl; |
| nd = lambda - node; |
| lambda = node + atan2(sin(nd)*cos(incl),cos(nd)); |
| |
| sl = sin(incl)*sin(nd); |
| beta = atan2(sl, pyth(sl)) + pturbb; |
| |
| lograd = pturbr*2.30258509; |
| rad *= 1 + lograd; |
| |
| |
| motion *= radian*mrad*mrad/(rad*rad); |
| |
| /* |
| * computation of magnitude |
| */ |
| |
| lsun = 99.696678 + 0.9856473354*eday; |
| lsun *= radian; |
| elong = lambda - lsun; |
| ci = (rad - cos(elong))/sqrt(1 + rad*rad - 2*rad*cos(elong)); |
| dlong = atan2(pyth(ci), ci)/radian; |
| mag = -4 + .01322*dlong + .0000004247*dlong*dlong*dlong; |
| |
| semi = 8.41; |
| |
| helio(); |
| geo(); |
| } |