Re-brightening and photometric modulation of the optical transient SSS130101:122222-311525
ATel #4744: Vitaly Neustroev (University of Oulu) and George Sjoberg (AAVSO):
We report a re-brightening and the consecutive detection of a photometric modulation of the recently discovered bright optical transient SSS130101:122222-311525 (Drake et al., ATel#4699).
This object has been in outburst since at least Dec 16, 2012 when it was found to be at V~11.8 (ATel#4700), some 7 mag brighter than it was previously. Subsequent photometry on Jan 1, 2013 showed the object still near maximum light at V = 12.3 +/- 0.1 (ATel#4699). However, the most recent reports indicated that SSS130101:122222-311525 had faded to magnitude 15.5 on Jan 4 and 16 on Jan 5 (vsnet-alert 15248).
Nevertheless, the data from our photometric monitoring indicate that after this decline a new increase in brightness has been observed during the last days. We performed time-resolved photometric observations of the object on Jan 10, 16 and 17 with the 0.35-m Celestron C14 robotic telescope, located at New Mexico Skies in Mayhill, New Mexico. We used an SBIG ST-10XME CCD camera with Johnson-Cousins BVRI Astrodon Photometric filters. On Jan 10, we obtained 10 images with an exposure time of 60 sec which gave an average magnitude of V=13.74+/-0.04. On Jan 16, we performed 2-hours of time-resolved observations with an exposure time of 30 sec. The average magnitude of these observations was V=12.48+/-0.03. On Jan 17, we obtained 2h 20min of multicolor BVRI photometry. Exposure times were 15 seconds for the VRI filters and 30 seconds for B. These observations gave the following magnitudes:
B=12.62+/-0.04, V=12.54+/-0.03, R=12.46+/-0.03, I=12.42+/-0.04
The observations from Jan 16 and 17 also revealed a photometric modulation with an amplitude of ~0.08 mag and a period of about 95 min or slightly longer. This period agrees with the estimates of Kuulkers et al. based on the spectroscopic observations (ATel#4716,#4704).
Kuulkers et al. proposed a WZ Sge-type dwarf nova classification for SSS130101:122222-311525. If this is correct then the object is expected to show a superhump signal during decline from superoutburst. We note, however, that even if the detected modulation is a superhump, the corresponding orbital period is still longer than WZ Sge stars usually have. This puts the WZ Sge classification of SSS130101:122222-311525 in doubt.
Photometry of SSS130101:122222-311525
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