[vsnet-alert 10475] TT Ind photometry on Aug. 30-31

Taichi Kato tkato at kusastro.kyoto-u.ac.jp
Mon Sep 1 10:19:49 JST 2008


   TT Ind photometry on Aug. 30-31

   Berto Monard has sent us time-resolved photometry of TT Ind during
the current outburst.  The observations on Aug. 30(-31) were taken
during the rising stage of the outburst.  In addition to the general
rising trend, there were modulations with time-scales of a few tens
of minutes to 3-4 hours.  There was not very convincing periodicity,
though superhumps, if any, are not yet expected to emerge at such
an early stage of an outburst.

   Further observations are very strongly encouraged.  If the object
is *not* an SU UMa-type dwarf nova, the large outburst amplitude and
the pattern of outbursts are very unusual for an SS Cyg-type dwarf nova.

   For the information, the late stage of the 2007 outburst was observed
by Berto Monard.  We failed to detect a coherent periodicity, but it
may have been that superhuumps had greatly reduced their amplitudes.
Having started observing from the early stage, the current outburst
will provide a better chance to detect any periodicity, and to reveal
the nature of this object.

  Recent observations:

  YYYYMMDD(UT)   mag  observer
  20080829.1149 <14.50V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080829.487   145  (Rod Stubbings)
  20080830.599   130  (Rod Stubbings)
  20080831.2111 13.169V  (ASAS (Pojmanski, G. 2002, Acta Astron. 52,397))
  20080831.446   120  (Rod Stubbings)


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