The 1998 August real outburst!

Minor outbutst of V592 Her (=Nova Her 1968)?

(vsnet-alert 422, Daisaku Nogami)

Dear colleagues,

Pierre Ouimet reports an outburst of V592 Her in vsnet-obs 2850 (originally in vsnet 629) as follows:

V592HER 960525.123      15.3

This star is suspected to be a WZ Sge star and a possible TOAD. Two outbursts have been observed in 1968 [1] and 1986 [2] and the recorded maximum brightnesses were 12.3 and 13.6 mag, respectively. Pierre might caught a new outburst in the rising phase, which is reminiscent of the uproar of the last year outburst in AL Com. Urgent confirmation is highly wanted.

Best regards,
Daisaku Nogami

[1] Richter 1968, IBVS No. 293
[2] Richter 1991, IBVS No. 3619

Negative observation by Iida

(vsnet-obs 2854)

CCD magnitude estimates by VSOLJ members

object         YYMMDD(UT)   mag  code
HERV592        960526.512  <158  Arm.VSOLJ

Observer's code:
  Arm: M. Iida (Nagano, Japan)  20-cm refl + ST-6 unfiltered

Further information on V592 Her

(vsnet-alert log)

(dated Mar 27, 1995)

Dear Colleagues,

As P. Schmeer and C. Scovil noticed, GW Lib seems to be observed at around mv=14-15. Since I am now at a remote terminal, the following information is based on my memory -- perhaps contains some errors. GW Lib was discovered as a possible nova by Gonzalez in 1983. The only available photometric data in IAUC suggests that the object reached at least 9th mag, and faded rather rapidly. No spectroscopic information during outburst was available. This discovery lead to a quiescent identification of mpg~18 star. The spectrum of this quiescent counter- part showed rather broad strong emission lines of H-alpha etc., and more resembled the spectrum of a dwarf nova in quiescence rather than that of a nova. Therefore some authors suspected this object to be a WZ Sge-type dwarf nova or a TOAD (tremendous outburst amplitude dwarf nova). No confirmed outburst has been recorded since its discovery in spite of close monitoring by visual observers. If the present possible brightening of GW Lib really reflects its outburst activity, it will surely provide a long-awaited opportunity in clarifying the nature of this poorly known cataclysmic variable. Confirmatory observations, spectroscopy, and photometry (time-resolved one, if possible), are most emergently requested. The finding chart can be found in many familiar articles such as the atlas by Duerbeck. A PostScript file is also available from our anonymous ftp service ( Note that this chart was based on GSC, but will be surely helpful in identifying the variable by visual observers. GW Lib itself was recorded at mag 16.6 on Mar. 19, 1993.

A PostScript file for V592 Her is also available ( in the same directory). This chart contains faint comparison stars down to V=17.8. Note that the quiescent identification by Duerbeck should be replaced by more recent one published in IBVS (sorry I don't remember the number). Our chart is based on this correct identification. V592 Her is also suspected to be a WZ Sge-type dwarf nova with a very long recurrence time and an exceptionally large (~10 mag) outburst amplitude. Other classifications, however, can not be ruled out. Please keep a close watch.

Taichi Kato

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