ref: e3aee39a389700ad821a1619f114e226c1bd42d0
dir: /sys/src/cmd/astro/stars.c/
#include "astro.h" char* startab = "/lib/sky/estartab"; void stars(void) { double lomoon, himoon, sd; int wrap, f, i; char *saop; static char saoa[100]; sd = 1000*radsec; lomoon = omoon.point[0].ra - sd; if(lomoon < 0) lomoon += pipi; himoon = omoon.point[NPTS+1].ra + sd; if(himoon > pipi) himoon -= pipi; lomoon *= 12/pi; himoon *= 12/pi; wrap = 0; if(lomoon > himoon) wrap++; f = open(startab, OREAD); if(f < 0) { fprint(2, "%s?\n", startab); return; } epoch = 1950.0; epoch = (epoch-1900.0) * 365.24220 + 0.313; saop = saoa; /* * read mean places of stars at epoch of star table */ loop: if(rline(f)) { close(f); return; } rah = atof(line+17); ram = atof(line+20); ras = atof(line+23); alpha = rah + ram/60 + ras/3600; if(wrap == 0) { if(alpha < lomoon || alpha > himoon) goto loop; } else if(alpha < lomoon && alpha > himoon) goto loop; sao = atof(line+0); sprint(saop, "%ld", sao); da = atof(line+30); dday = atof(line+37); dmin = atof(line+41); dsec = atof(line+44); dd = atof(line+50); px = atof(line+57); mag = atof(line+61); /* * convert rt ascension and declination to internal format */ delta = fabs(dday) + dmin/60 + dsec/3600; if(dday < 0) delta = -delta; star(); /* * if(fabs(beta) > 6.55*radian) * goto loop; */ sd = .0896833e0*cos(beta)*sin(lambda-1.3820+.00092422117*eday) + 0.99597*sin(beta); if(fabs(sd) > .0183) goto loop; for(i=0; i<=NPTS+1; i++) setobj(&ostar.point[i]); occult(&omoon, &ostar, 0); if(occ.t1 >= 0 || occ.t5 >= 0) { i = PTIME; if(mag > 2) i |= DARK; if(mag < 5) i |= SIGNIF; if(occ.t1 >= 0 && occ.e1 >= 0) event("Occultation of SAO %s begins at ", saop, "", occ.t1, i); if(occ.t5 >= 0 && occ.e5 >= 0) event("Occultation of SAO %s ends at ", saop, "", occ.t5, i); while(*saop++) ; } goto loop; }