On 2021-10-03 10:07, Patrick Schmeer via vsnet-alert wrote:
> GK Persei  (NA+UG+NLDQ)
> Orbital period: 1.996803 d
> White dwarf spin period: 0.0040625 d = 5.85 min = 351 s
> https://www.aavso.org/vsx/index.php?view=detail.top&oid=25717
>
> Beginning of the brightening noticed yesterday during my regular
> check of ASAS-SN Sky Patrol data.
> https://asas-sn.osu.edu/sky-patrol/coordinate/485c8c41-e472-4da9-ab5c-c42c04afd4c1
>
> I then checked the latest AAVSO data, but the latest observation
> was (and still is) from 2021 Sept. 30.935 UT:
> https://app.aavso.org/webobs/results/?star=000-BBG-044
>
> No visual confirmation by me due to bad weather last night.
>
> The latest ZTF observation is from 2021 Sept. 14.384 UT:
> https://lasair.roe.ac.uk/object/ZTF18abnzukj/
>
> The beginning outburst was also noted by Y. Maeda
> (Oct. 2.613 UT, mag. 126cG; see vsnet-outburst 27777).
>
> The previous dwarf nova outburst of GK Per was observed from
> 2018 August 23 to October 28 (optical peak on Sept. 24, V= 10.1).
>
> Follow-up observations (e.g. spectroscopy) are encouraged.
>
> Clear skies,
> Patrick
> -------
> References:
> All-Sky Automated Survey for Supernovae (ASAS-SN) Sky Patrol:
> - Shappee et al., 2014ApJ...788...48S
> - Kochanek et al., 2017PASP..129j4502K
> Lasair:
> - Smith et al., 2019RNAAS...3...26S
> Zwicky Transient Facility (ZTF):
> - Masci et al., 2019PASP..131a8003M