set output 'rrlyr_curve_b.ps' 
set term postscript enhanced color 'Helvetica,18'  
set style line 1 lt rgb 'red' lw 3  
set style line 2 lt rgb 'sea-green' lw 3  
set style line 3 lt rgb 'blue' lw 3  
set style line 4 lt rgb 'cyan' lw 3  
set style line 5 lt rgb 'violet' lw 3  
set grid 
set key top right 
set xlabel 'Time (days) ' 
set ylabel 'Instrumental magnitude ' 
set title 'TESS measurements of RR Lyr '
plot [1685:1690][7.7:7.0] 'rrlyr_sap.txt' using ($1):(20-2.5*(log10($2)))  ls 1 ps 0.2 t ''  
set output 
quit 
