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[vsnet-campaign 538] DM Dra very rare outburst: emergent request for observations!

DM Dra very rare outburst: emergent request for observations!

   As reported by Patrick Schmeer, the large-amplitude dwarf nova DM Dra
is undergoing a very rare, bright outburst.

   The object had been monitored visually for serveral years, but there
was no confirmed outburst reported to VSNET, except two suspected sightings
by Timo Kinnunen (1998 Sep. 25, 16.0: and 2000 Sep. 30, 15.9:).  The current
brightness and the duration of outburst very strongly suggest a superoutburst.

   The object was originally discovered by Stepanyan, as SVS 2426.  The object
was observed spectroscopically during outburst on JD 2443965 (mag 15.5);
the low resolution spectrum resembled that of an O-B star, which is consistent
with the dwarf nova classification.  Stepanyan reported the quiescent
magnitude of 20.  More recent CCD photometry in quiescence (Howell et al.)
showed the object at V=20.8, and suggested a possible periodicity of 125
min.  They reported a temprary fading 0.4 mag in 5 min, which may have been
an eclipse.

   The object is selected as one of the top-priority targets of the
VSNET campaign.

   ---

Subject: [vsnet-alert 5338] DM Dra very bright outburst

DM DRACONIS  (UGSU:)

CCD magnitudes obtained by P. Schmeer, Bischmisheim, Germany:
DRADM  20000522.289 <175C  Scp
DRADM  20001017.078  144C  Scp
DRADM  20001018.081  141C  Scp
DRADM  20001026.085  154C  Scp
Sequence:   USNO-A2.0 (red magnitudes)
Instrument: IRO (0.5-m RCT + AP-8)

The current rare outburst may well be a supermaximum. Time-resolved
photometry during its final stage is very urgently required.

Clear skies,
Patrick

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