We present a comprehensive re-analysis of stellar photometric variability in the field of the open cluster M37 following the application of a new photometry and de-trending method to the MMT/Megacam image archive. This new analysis allows a rare opportunity to explore photometric variability over a broad range of timescales, from minutes to a month. The intent of this work is to examine the entire sample of more than 30000 objects for periodic, aperiodic, and sporadic behaviors in their light curves. We show a modified version of the fast {chi}^2^ periodogram algorithm (F{chi}^2^) and change-point analysis as tools for detecting and assessing the significance of periodic and non-periodic variations. The benefits of our new photometry and analysis methods are evident. A total of 2306 stars exhibit convincing variations that are induced by flares, pulsations, eclipses, starspots, and unknown causes in some cases. This represents a 60% increase in the number of variables known in this field. Moreover, 30 of the previously identified variables are found to be false positives resulting from time-dependent systematic effects. The new catalog includes 61 eclipsing binary systems, 92 multiperiodic variable stars, 132 aperiodic variables, and 436 flare stars, as well as several hundreds of rotating variables. Based on extended and improved catalog of variables, we investigate the basic properties (e.g., period, amplitude, type) of all variables. The catalog can be accessed through the web interface (http://stardb.yonsei.ac.kr/).

Cone search capability for table J/AJ/150/27/table7 (436 flare stars)

Cone search capability for table J/AJ/150/27/table5 (Candidate frequencies identified in 92 multiperiodic light curves)

Cone search capability for table J/AJ/150/27/table6 (Long-term 132 aperiodic variable candidates with timescales of >1 month)

Cone search capability for table J/AJ/150/27/table1 (New catalog of 2306 variable stars in M37 field)

Cone search capability for table J/AJ/150/27/table2 (List of 30 stars whose variability turns out to be false)

Cone search capability for table J/AJ/150/27/table4 (List of new 15 eclipsing binary candidates from the Change-Point Analysis (CPA) analysis)