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Express analysis of recent superoutburst of NSV 09923 NSV 09923 has been recently classified as a SU UMa-type dwarf nova (see the VSNET Web page http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/nsv09923.html ) Its observations obtained on July 2-3 [vsnet-campaign-dn 3833] and July 4-5 [vsnet-campaign-dn 3843] have been published by B.Monard (CBA Pretoria) have been analyzed using the periodogram (I.L.Andronov, Odessa Astron. Publ., 1994, 7, 49, http://oap14.pochta.ru/oap09.htm) and "running sine" scalegram (I.L.Andronov, Astron. Astrophys.Suppl., 1997, 125, 207) analysis. Both runs show a low-frequency trend which have been approximated by a parabola. The periodogram for residuals shows the highest peak corresponding to T Max=2452823.377(1) Period=0.08319(62) Semi-Amplitude=.0415(32) The second peak occurs at nearly double frequency (P=0.04099(17)) and shows nearly the same amplitude of 0.039 mag. This corresponds to a large asymmetry (M-m~0.25) of the superhump profile. There is also a secondary pulse during the superhump, which has drastically increased in amplitude during a run, and occurs ~0.4P after the main maximum. This possibly may be interpreted as a process of cration of the second spiral wave. For the second run, T Max=2452825.379(2) Period=0.07902(167) Semi-Amplitude=0.0197(33) The peak corresponding approximately to a double frequency appears at P=.04359(60) and corresponds to an amplitude of 0.015. However, much more prominent is the splitted peak corresponding to 48 and 50.4 cycles/day (30 and 28,6 minutes; 0.017 and 0.018 mag, repectively). It is interesting to note another double peak at 105 and 114.4 cycles/day (13.7 and 12.6 minutes; 0.013 and 0.014 mag, respectively). It is interesting to note, that, during the first run, when the system was by 0.33 mag brighter, than in the second, there were only asymmetric superhumps, whereas at slightly lower state, one could observe quasi-periodic oscillations at two scales of 30 and 13 minutes superimposed on superhumps of twice smaller amplitude. For the residuals from two runs, T Max=2452824.211(1) Period=0.08341(8) Ampl.=.0319(24) with a 2d-bias at P=0.08006(9), Ampl=.030 This value of the period differs from that 0.08235(2) d published by T.Kato-san [vsnet-superoutburst 2124] NSV09923: no fading + refined superhump period. Our value seem to be a better approximation for the residuals from low-frequency trend. The scalegram analysis confirms the variability at time scales of 2 hours, 30 and 13 minutes; no clear evidence of sources of QPOs of low coherence is seen. There is a modulation of the light curve, which is to be monitored densely. It may be "some indication of a beat phenomenon" (T.Kato), as well as indication of other mechanisms of variability of the accretion disk. Ivan L.Andronov Department of Astronomy, Odessa National University, Ukraine; Crimean Astrophysical Observatory, Ukraine http://il-a.pochta.ru
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