Characteristics of Blazhko stars from ZTF & LINEAR

A preliminary subsample of about ~500 stars was algorithmically preselected using various data quality and light curve statistics, and then 228 stars were confirmed visually as displaying the Blazhko effect.

This sample increases the number of field RR Lyrae stars displaying the Blazhko effect by more than 50% and places a lower limit of (11.4+/-0.8)% for their incidence rate. We find that ab type RR Lyrae that show the Blazhko effect have about 5% (0.030 day) shorter periods than starting sample, a 7.1{sigma} statistically significant difference. We find no significant differences in their light curve amplitudes and apparent magnitude (essentially, signal-to-noise ratio) distributions.