DW Cancri (NLDQ+UG) Orbital period: 0.0597927 d = 86.1015 min White dwarf spin period: 0.02679 d = 38.5776 min = 2314.656 s https://www.aavso.org/vsx/index.php?view=detail.top&oid=4949 https://asd.gsfc.nasa.gov/Koji.Mukai/iphome/systems/dwcnc.html

The current outburst started shortly before 2021 Oct. 4.422 UT according to recent ASAS-SN Sky Patrol data: https://asas-sn.osu.edu/sky-patrol/coordinate/4ad48fe8-9c3f-484e-861e-a5f66f... CNCDW 20210924.572 15.243g ASN CNCDW 20211004.422 14.565g ASN CNCDW 20211004.424 14.554g ASN CNCDW 20211004.425 14.480g ASN

DW Cnc was at mag. 11.3cG on Oct. 4.832 UT (outburst detection, by Yutaka Maeda; see below).

AAVSO data: https://app.aavso.org/webobs/results/?star=000-BBN-975

ZTF light curve, data, and images (via Lasair): https://lasair.roe.ac.uk/object/ZTF20acuafnq/ https://lasair.roe.ac.uk/object/ZTF17aabhbir/

T. Kato wrote (vsnet-alert 26290, see below):

outburst for the first time since 2007!!

A short and apparently faint outburst was observed by H. Maehara on 2021 February 6.690 UT at mv= 13.6 (vsnet-alert 25340). The 2007 outburst was observed from January 25 to 27 (observed optical peak on Jan. 25.297 UT at brighter than 11.36V).

Follow-up observations are urgently required.

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 -------------- Taichi Kato wrote on Tuesday, 5 October 2021, 05:29:41 UTC:

DW Cnc outburst Maeda-san reported 11.3 mag on 20211004.83223 [vsnet-outburst 27783] outburst for the firsttime since 2007 !!