  GY Cnc is a deeply eclipsing cataclysmic variable star with an orbital period
of 4.21 hours that has shown several dwarf nova outbursts. The variable was
continuously observed by the K2/Kepler satellite with a short cadence in
Campaign 5 (C05) for 75 days during 2015. The star was again observed in
2017/2018 for 80 consecutive days during Campaign 16 (C16). 419 well-observed
eclipses were measured over C5 and 446 timings were determined in C16. A new
ephemeris was calculated combining the K2 data, previously published timings,
new light curves from the KELT Follow-Up Network, and additional observations
in the AAVSO database. We have refined the orbital period of GY Cnc and
improved its ephemeris which had accumulated an error of about 300s over 18
years. A quadratic term was not found to be significant indicating that there
is currently no detectable orbital period derivative. We observed a correlation
between the quiescent system brightness and the eclipse timing residuals that
are as large as +/-15s in the K2 data.
