AAVSO: American Association of Variable Star Observers

High Occurrence Optical Spikes and Quasi-Periodic Pulses (QPPs) on X-ray Star 47 Cas

Volume 47 number 2 (2019)

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Gary Vander Haagen
Stonegate Observatory, 825 Stonegate Road, Ann Arbor, MI 48103; garyvh2@gmail.com


The high cadence flare search of X-ray star 47 Cas revealed 46 B-band flares at 0.26 to 0.78 mag peak above the mean. Durations of the very short flares or spikes ranged from 20 to 220 ms and energy levels from 22.7 to 199.5 × 10^31 ergs. The study collected 2.6 × 10^7 photometric measurements over 32.3 hours from October 19, 2018, through April 9, 2019. The 46 flares identified represent a flare rate of 4.6 flares/hour during the 500 samples/sec sampling period. The analysis showed numerous quasi-periodic pulses (QPPs) accompanying the spikes, with the most predominant frequencies of 2 to 12 Hz.