set angles degrees
unset grid

f(a,b,dec,ra)=acos(((sin(a)-sin(b)*sin(dec))/(cos(b)*cos(dec))))/15+ra/15
f24(a,b,dec,ra)=24-acos(((sin(a)-sin(b)*sin(dec))/(cos(b)*cos(dec))))/15+ra/15

set label "29" at 18.9668,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "28" at 18.961,43.5849 center font "Symbol,9" tc rgb "red" front
set label "28" at 18.879,46.9811 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "27" at 18.9386,40.7547 center font "Symbol,9" tc rgb "red" front
set label "27" at 18.851,44.1509 center font "Symbol,9" tc rgb "red" front
set label "27" at 18.7635,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "26" at 18.8467,40.7547 center font "Symbol,9" tc rgb "red" front
set label "26" at 18.7544,44.1509 center font "Symbol,9" tc rgb "red" front
set label "26" at 18.6612,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "25" at 18.7544,40.7547 center font "Symbol,9" tc rgb "red" front
set label "25" at 18.6573,44.1509 center font "Symbol,9" tc rgb "red" front
set label "25" at 18.5584,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "24" at 18.6617,40.7547 center font "Symbol,9" tc rgb "red" front
set label "24" at 18.5598,44.1509 center font "Symbol,9" tc rgb "red" front
set label "24" at 18.455,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "23" at 18.5686,40.7547 center font "Symbol,9" tc rgb "red" front
set label "23" at 18.4618,44.1509 center font "Symbol,9" tc rgb "red" front
set label "23" at 18.3511,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "22" at 18.4751,40.7547 center font "Symbol,9" tc rgb "red" front
set label "22" at 18.3633,44.1509 center font "Symbol,9" tc rgb "red" front
set label "22" at 18.2465,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "21" at 18.3811,40.7547 center font "Symbol,9" tc rgb "red" front
set label "21" at 18.2642,44.1509 center font "Symbol,9" tc rgb "red" front
set label "21" at 18.1413,47.5472 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "20" at 18.2866,40.7547 center font "Symbol,9" tc rgb "red" front
set label "20" at 18.1646,44.1509 center font "Symbol,9" tc rgb "red" front
set label "19" at 18.1916,40.7547 center font "Symbol,9" tc rgb "red" front
set label "" at 0,0 center font "Symbol,9" tc rgb "red" front
set label "18" at 18.096,40.7547 center font "Symbol,9" tc rgb "red" front

set label "" at 0,0 center font "Symbol,9" tc rgb "blue" front
set label "19" at 18.0218,41.3208 center font "Symbol,9" tc rgb "blue" front
set label "18" at 18.248,41.3208 center font "Symbol,9" tc rgb "blue" front
set label "17" at 18.451,41.3208 center font "Symbol,9" tc rgb "blue" front
set label "" at 0,0 center font "Symbol,9" tc rgb "blue" front
set label "16" at 18.6375,41.3208 center font "Symbol,9" tc rgb "blue" front
set label "16" at 18.0618,44.3774 center font "Symbol,9" tc rgb "blue" front
set label "15" at 18.8113,41.3208 center font "Symbol,9" tc rgb "blue" front
set label "15" at 18.225,44.717 center font "Symbol,9" tc rgb "blue" front
set label "14" at 18.8177,42.4528 center font "Symbol,9" tc rgb "blue" front
set label "14" at 18.2164,45.8491 center font "Symbol,9" tc rgb "blue" front
set label "13" at 18.8243,43.5849 center font "Symbol,9" tc rgb "blue" front
set label "13" at 18.2074,46.9811 center font "Symbol,9" tc rgb "blue" front
set label "12" at 18.8309,44.717 center font "Symbol,9" tc rgb "blue" front
set label "12" at 18.198,48.1132 center font "Symbol,9" tc rgb "blue" front
set label "11" at 18.8377,45.8491 center font "Symbol,9" tc rgb "blue" front
set label "11" at 18.2033,49.1887 center font "Symbol,9" tc rgb "blue" front
set label "10" at 18.6537,48.1132 center font "Symbol,9" tc rgb "blue" front
set label "9" at 18.6552,49.2453 center font "Symbol,9" tc rgb "blue" front
set label "8" at 18.7603,49.8113 center font "Symbol,9" tc rgb "blue" front

set label "" at 0,0 center font "Symbol,9" tc rgb "green" front
set label "49" at 18.0974,48.6792 center font "Symbol,9" tc rgb "green" front
set label "48" at 18.1227,46.9811 center font "Symbol,9" tc rgb "green" front
set label "" at 0,0 center font "Symbol,9" tc rgb "green" front
set label "47" at 18.1425,45.283 center font "Symbol,9" tc rgb "green" front
set label "47" at 18.3238,48.6792 center font "Symbol,9" tc rgb "green" front
set label "46" at 18.1573,43.5849 center font "Symbol,9" tc rgb "green" front
set label "46" at 18.3454,46.9811 center font "Symbol,9" tc rgb "green" front
set label "" at 0,0 center font "Symbol,9" tc rgb "green" front
set label "45" at 18.1677,41.8868 center font "Symbol,9" tc rgb "green" front
set label "45" at 18.362,45.283 center font "Symbol,9" tc rgb "green" front
set label "45" at 18.5532,48.6792 center font "Symbol,9" tc rgb "green" front
set label "44" at 18.2746,41.8868 center font "Symbol,9" tc rgb "green" front
set label "44" at 18.4727,45.283 center font "Symbol,9" tc rgb "green" front
set label "44" at 18.6692,48.6792 center font "Symbol,9" tc rgb "green" front
set label "43" at 18.382,41.8868 center font "Symbol,9" tc rgb "green" front
set label "43" at 18.5841,45.283 center font "Symbol,9" tc rgb "green" front
set label "43" at 18.786,48.6792 center font "Symbol,9" tc rgb "green" front
set label "42" at 18.49,41.8868 center font "Symbol,9" tc rgb "green" front
set label "42" at 18.6963,45.283 center font "Symbol,9" tc rgb "green" front
set label "42" at 18.9037,48.6792 center font "Symbol,9" tc rgb "green" front
set label "41" at 18.5985,41.8868 center font "Symbol,9" tc rgb "green" front
set label "41" at 18.8093,45.283 center font "Symbol,9" tc rgb "green" front
set label "" at 0,0 center font "Symbol,9" tc rgb "green" front
set label "40" at 18.7078,41.8868 center font "Symbol,9" tc rgb "green" front
set label "" at 0,0 center font "Symbol,9" tc rgb "green" front
set label "39" at 18.8177,41.8868 center font "Symbol,9" tc rgb "green" front
set label "" at 0,0 center font "Symbol,9" tc rgb "green" front

set parametric
set view 0, 359, 1, 1
set samples 100, 100
set isosamples 160, 160
unset surface
set contour base
unset clabel
set mapping cartesian
unset hidden3d
set cntrparam levels auto 100
set cntrparam points 5
set trange [ 0.000000 : 90.0000 ] noreverse nowriteback
set urange [ 0.000000 : 90.0000 ] noreverse nowriteback
set vrange [ 0.000000 : 90.0000 ] noreverse nowriteback
set xlabel "x lha"=20
set xrange [ 18.0000 : 19.0000 ] noreverse nowriteback
set ylabel "y lat"=20
set yrange [ 40.0000 : 50.0000 ] noreverse nowriteback
set zlabel "z alt"=20
set zrange [ 5.00000 : 60.0000 ] noreverse nowriteback

f(u,v,dec,ra)=acos(   (sin(u)-sin(v)*sin(dec))  /  (cos(v)*cos(dec)) )/15+ra/15

GNUTERM = "win"
se vi map
splot f24(u,v,29.14086,2.21),v,u  t 'Alpheratz' , f(u,v,-26.45,247.5),v,u t "Antares", f(u,v,49.2666,206.98),v,u t "Alkaid" w l lc rgb "green"