Based on 6 nights of photometric observations between 2007, Aug 26th and 2007, Sep 07th, during quiescence of the variable, D. Denisenko found an orbital period of either 0.0717d and 0.0771d (i.e., 14 and 13 revolutions per day). It was impossible to further distinguish between these two aliases.

The light curve shows a decline by 0.8 mag/day, but no apparent modulations in any of the datasets. An extensive analysis using various period analysis methods in Peranso did not reveal any strong signal. 

From precursor outburst to superoutburst

At a moment that everyone was assuming that the variable had returned to quiescence, Patrick Schmeer reported his detection of another outburst of NSV 1485, on 2007, Sep 19th. When I received Patrick's phone call (thanks Patrick !) around 10 PM local time that evening, skies were completely overcast, but the weather satellite images showed a possible clearing later that night. I woke up around 0h UT (Sep 20th) and saw a clear sky.

It remained clear for about 3 hours, during which I started an unfiltered CCD photometry session on NSV 1485, using again a 0.35-m f/6.3 telescope and SBIG ST-7XME CCD camera. The resulting lightcurve, based on a 2.5 hrs session, is shown below and clearly reveals the presence of superhumps, hence classifying NSV 1485 as a new UGSU-type dwarf nova. Using Peranso's ANOVA method, I find a superhump period value of 0.076 +/- 0.001d, and an amplitude of about 0.15 mag. The period window and phase diagram are shown below. My superhump period value seems to favor the orbital period alias of 0.0771d (but see the discussion on the superhump refinement below).

NSV 1485's precursor outburst occured about 10 days before this main superoutburst. A similar combination of outbursts was recorded during the 1998 outburst of QZ Vir (aka T Leo). QZ Vir underwent a supposed precursor outburst on 1998 Apr 2, followed by a superoutburst 10 days later.

Additional CBA observations of NSV 1485

Combined with my Sep 19/20 obs, the CBA dataset for NSV 1485 now comprises 1191 superoutburst observations. Using Peranso's implementation of the ANOVA method (A. Schwarzenberg-Czerny), I find a superhump period of 0.07421 +/- 0.00010d. See the period window below. This is slightly shorter than the value I found on Sep 19/20 (see above), but which was based on a *much* shorter timeline. 

The amplitude derived from all CBA observations is about 0.18 mag. The phase diagram (see below) shows a small dip on the descending branch of the superhump modulation, but I'm not sure how to interpret this. Further observations might tell.