| Type | DN, SU |
| Period (d) | 0.089 (0.093) |
| Mag | 18.5 (13.3) |
| a(2000) | 00 49 01.5 |
| d(2000) | +56 52 44 |
|
Image from TKUCO 12.5" F/4.8 |
During October 1999 GX Cas went into outburst. Positive identification of SuperHumps was secured by several observing groups including Martin and Anderson. The following panels show the development of SH's
| October 23: Beginning at UT 2:30, observer Martin, mean scatter approx.: 0.02 mag, unfiltered using CB245, 12.5" F4.8, 100 s. |  |
| October 24: Beginning at UT 2:00, observer Martin, mean scatter approx.: 0.04 mag, unfiltered using CB245, 12.5" F4.8, 100 s. |  |
| October 25: Beginning at UT 3:40, observer Martin, mean scatter approx.: 0.01 mag, unfiltered using CB245, 12.5" F4.8, 100 s. |  |
| October 27: Beginning at UT 3:40, observer Anderson, mean scatter approx.: 0.01 mag, unfiltered using CB245, 18" F6, 100 s. |  |
Period analysis was conducted using both PDM (PDMWIN V3.0 -Widjaja) and Fourier (Period 98 - Sperl). The following panels show the PDM and Fourier spectra obtained:
| PDM, P = 0.09313 d +/- 0.00001d, q = 0.291 | DFT, P = 0.09311 d +/-0.00001d |
 |
 DFT |