m3_B_20120402_00013dfw.fits
TARGET  = 'M3      '           / target
EXPTIME =              3.0E+02 / exposure time (seconds)
FILTER  = ' (2) B (375-490) '  / filter
DATE-OBS= '2012-04-03T04:38:36' / date of observation (UT)

m3_R_20120402_00014dfw.fits
TARGET  = 'M3      '           / target
EXPTIME =              3.0E+02 / exposure time (seconds)
FILTER  = ' (4) R (570-690) '  / filter
DATE-OBS= '2012-04-03T04:30:55' / date of observation (UT)

m3_V_20120402_00015dfw.fits
TARGET  = 'M3      '           / target
EXPTIME =              3.0E+02 / exposure time (seconds)
FILTER  = ' (3) V (490-580) '  / filter
DATE-OBS= '2012-04-03T04:25:12' / date of observation (UT)