Night-by-night VHE (E>400GeV) light curve for Mrk 421 from 1995 to 2009, based on measurements made with the Whipple 10m imaging atmospheric-Cherenkov telescope.
The data-point values for the plot are provided in plain ASCII form in the file here. For each of the 783 nights on which Whipple 10m observations of Mrk 421 were carried out, the file contains contains six values: the entry number (1-783); Ti, the time (Modified Julian Date, MJD) at which Mrk 421 observations began; Tf, the time (MJD) at which Mrk 421 observations ended; T, the mean time (MJD) of the Mrk 421 observations (in some cases, T does not lie midway between Ti and Tf because of gaps in the Mrk 421 observations on the night); R, the gamma-ray rate above 400 GeV, in units of the Crab Nebula flux above 400 GeV; dR, the statistical uncertainty on the rate.
These data are provided as supplementary material to the Acciari et al paper [here]: Astroparticle Physics 54, 1, (2014). If you wish to make use of the data, we ask that you advise us of your plans by emailing the VERITAS spokesperson and acknowledge the source of the information by citing the Acciari et al paper and by referencing this webpage [http://veritas.sao.arizona.edu/veritas-science/mrk-421-long-term-lightcurve].