[vsnet-alert 13739] DDE 22: interesting behavior

Denis Denisenko d.v.denisenko at gmail.com
Sat Oct 8 06:18:31 JST 2011


Possible UGZ-type variable DDE 22 in Camelopardalis is showing a
curious light curve. According to observations at Montecatini on Oct.
5/6 (Fabio Martinelli) and Ka-Dar Observatory's TAU station on Oct.
6/7 and 7/8 (remotely by Stas Korotkiy and Vladimir Gerke), the star
has reached its outburst near Oct. 6.8 UT at 16.8m. Tonight it is
already fainter by 0.15m than the night before:

  YYYYMMDD(UT)   mag  observer
  20111005.888  16.86 Montecatini
  20111005.925  16.89 Montecatini
  20111006.912  16.76 Ka-Dar, TAU
  20111007.831  16.91 Ka-Dar, TAU

Both previous outbursts had maxima brighter by ~0.5m:

  YYYYMMDD(UT)   mag  observer
  20110901.849  16.16 Ka-Dar, TAU
  20110921.012  16.28 Ka-Dar, TAU

Note: actually there were no observations on Sep. 02/03 UT, so the 1st
maximum could have been even brighter than 16.1. Intervals between
consequent maxima are 18 (17?) and 16 days.

Screenshot of the light curve from AAVSO LCG:
http://pics.livejournal.com/bigdenru/pic/000ae3a2

Could this reduction of outburst maxima be a sign of the incoming
standstill? Continued monitoring is encouraged.

Denis Denisenko


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