[vsnet-alert 21226] DDE 99 = GALEX J220630.7-524419 outburst

[Denis Denisenko]

The dwarf nova in Indus DDE 99 = GALEX J220630.7-524419 = GSC
08809-00294 appears to be going into its first outburst since it was
identified as a cataclysmic variable in May of this year. I have been
monitoring it with iTelescope.Net T32 recently, and it has brightened
by almost 2m within 24 hours:

  20170705.7686  18.89CV  T32
  20170706.7829  18.53CV  T32
  20170707.6756  18.26CV  T32
  20170708.6710  16.54CV  T32  Rising!

Comparison star labeled 138 in AAVSO sequence with V=13.796 was used
as a reference.

The variable shows two types of outbursts in both SSS and ASAS-SN
data: short ones to 15.6m lasting 4-5 days and long ones to 14.8m
lasting 10-12 days. The dates of the recent bright outbursts are:

  20160606.2566  14.80V  ASN
  20160805.2415  15.00V  ASN
  20161006.0759  15.07V  ASN
  20161130.1172  15.10V  ASN
(-- insert seasonal gap here --)
  20170513.3238  15.05V  ASN

Judging from 2016 data, the cycle between bright outbursts is just
under two months. Thus, today is the right time for the next one.

Time-resolved photometry is encouraged to see if the current outburst
is the superoutburst. The orbital period is unknown.

AAVSO VSX entry: https://www.aavso.org/vsx/index.php?view=detail.top&oid=477734

Denis Denisenko (DDE)
http://scan.sai.msu.ru/~denis/VarDDE.html