Nova V723 Cas off in X-rays
ATel #8053; J.-U. Ness (ESA/ESAC), V. P. Goranskij (SAI, Moscow University), K. L. Page and J. Osborne (Leicester), G. Schwarz (AAS)
on 14 Sep 2015; 11:39 UT
Distributed as an Instant Email Notice Novae
Credential Certification: Jan-Uwe Ness (juness@sciops.esa.int)
Subjects: X-ray, Cataclysmic Variable, Nova
Nova V723 Cas, discovered 1995-08-24, was first observed in X-rays with
Swift as a super soft source on 2006-01-31 (Ness et al., 2006, IAUC # 8676),
3813 days after discovery. It was then monitored in X-rays with Swift
with roughly six months spacing with some results reported by
Ness et al. (2008, AJ 135, 1328). Schwarz et al. (2011, ApJS 197, 31)
reported on all X-ray data until day 5308 after outburst with all
observations containing SSS emission.
We report here on the last four
X-ray observations that constrain the turn off:
Date | Days after discovery | exp. time(ks) | count rate (10^-3)
2013-08-09/10 | 6561 | 1.46 | 5+/-2
2013-08-19 | 6571 | 0.63 | < 13
2014-04-01 | 6795 | 4.89 | < 2
2014-09-13 | 6960 | 4.85 | < 2
The last detection was achieved on day 6561 after discovery while
only 10 days later, the source was not detected. Unfortunately,
the upper limit on day 6571 is too high to conclude that the source
had turned off, but it had definitely turned off before day 6795.
The total life time of this nova, from optical discovery to last
signs of activity in X-rays, can thus be constrained between
6571-6960 days or 18-19 years.
