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Dear colleagues,
Our paper summarizing the VSNET campain of Var73 Dra 2002-2003
was accepted for publication of Astronomy & Astrophysics. The
abstract is as below. A PDF file of the paper is available at
http://vsnet.kusastro.kyoto-u.ac.jp/pub/vsnet/preprints/Var73_Dra/var73dra.pdf .
Thank you very much for your contribution. Enjoy reading the
preprint!
Best regards,
Daisaku Nogami
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Title: In-the-Gap SU UMa-Type Dwarf Nova, Var73 Dra with a Supercycle
of about 60 Days
Authors: D. Nogami, M. Uemura, R. Ishioka, T. Kato, K. Torii, D.R. Starkey,
K. Tanabe, T. Vanmunster, E.P. Pavlenko, V.P. Goranskij, E.A. Barsukova,
O. Antoniuk, B. Martin, L.M. Cook, G. Masi, F. Mallia
Abstract:
An intensive photometric-observation campaign of the recently discovered
SU UMa-type dwarf nova, Var73 Dra was conducted from 2002 August to 2003
February. We caught three superoutbursts in 2002 October, December and
2003 February. The recurrence cycle of the superoutburst (supercycle)
is indicated to be $\sim$60 d, the shortest among the values known so far
in SU UMa stars and close to those of ER UMa stars. The superhump
periods measured during the first two superoutbursts were 0.104885(93) d,
and 0.10623(16) d, respectively. A 0.10424(3)-d periodicity was
detected in quiescence. The change rate of the superhump period during
the second superoutburst was $1.7\times10^{-3}$, which is an order of
magnitude larger than the largest value ever known. Outburst activity
has changed from a phase of frequent normal outbursts and infrequent
superoutbursts in 2001 to a phase of infrequent normal outbursts and
frequent superoutbursts in 2002. Our observations are negative to an
idea that this star is an related object to ER UMa stars in terms of the
duty cycle of the superoutburst and the recurrence cycle of the normal
outburst. However, to trace the superhump evolution throughout a
superoutburst, and from quiescence more effectively, may give a fruitful
result on this matter.
Return to the Powerful Daisaku Nogami
vsnet-adm@kusastro.kyoto-u.ac.jp
