IY UMa Figure 5.

Figure 5. Sample blow-ups of individual eclipses. All this data (in contrast to the above V-band data) was obtained through a Schott BG38 filter, which for an intrinsically blue star has an effective "wide B" passband. Eclipse numbers are shown at upper right. The differential photometry is rendered on an intensity scale. Each eclipse has four rapid phases (white dwarf ingress, bright spot ingress, white dwarf egress, bright spot egress), plus a more gradual event (disk eclipse?). Phase zero is defined as the white dwarf's mid-eclipse, which can be timed to very high accuracy (~3 s); the bright spot's center of light is displaced to much later phase, as can easily be seen. The points are at ~17 s intervals.

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