[vsnet-alert 23111] Re: V618 Sgr brightening

[Patrick Schmeer pasc1312-aavso@yahoo.de via vsnet-alert]

V618 Sagittarii  (ZAND)
https://www.aavso.org/vsx/index.php?view=detail.top&oid=28318

The ongoing bright outburst began around 2017 August 11.
Please note also the deep fading that started around
2018 July 26. Eclipse? Probably not caused by dust
formation as g-V stayed at about +0.2 mag during the
whole outburst and even the deep fading; see the complete
ASAS-SN Sky Patrol light curve (Shappee et al. 2014ApJ
...788...48S and Kochanek et al. 2017PASP..129j4502K):
https://asas-sn.osu.edu/light_curves/657be8bc-206e-4d11-b36a-741aec7670a0

See also:
http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/23020
http://ooruri.kusastro.kyoto-u.ac.jp/mailarchive/vsnet-alert/23030
https://groups.google.com/forum/#!msg/variablestarssouth/PQM1RLRx9NI/Lr1orcWjDAAJ

Regards,
Patrick
---------------

Taichi Kato wrote (vsnet-alert 23030):

> Kojima-san reported the brightening of V618 Sgr as
> follows. This brightening was also recorded in the
> ASAS-SN database.

Note that this object had been very faint for decades
before the rise in 2017 Aug. The current amplitude
is unusually large for a symbiotic star and something
unexpected may be taking place. Spectroscopy would
be desirable.