ИСТИНА

In this paper we have presented a review of the new optical transient detection system at the Sutherland observing station of the SAAO, namely MASTER-SAAO, the first MASTER II system established in the southern hemisphere, which began operations in mid-Dec 2014. We have reviewed the specifications and modus operandi for the MASTER system, and particularly MASTER-SAAO, and its survey for transients, focusing on the results of new CV discoveries. In the ~9 months of operations, MASTER-SAAO has discovered 141 new non-Solar System optical transients (in addition to two comets and several minor planets) during its survey mode. In addition it has conducted follow-up observations of ~10 other transient detections, originating from other alert systems (e.g. Swift, Fermi), including GRB afterglow searches and monitoring of AGN [19]. A total of 111 new CVs have been discovered with MASTER-SAAO, a significant advance and resulting in a total of 530 new CVs discovered by the entire MASTER network in its 5.7 years of operations. The study conducted on the CVs detected in the CRTS [11] demonstrated that most new CVs discovered through transient detection systems are Dwarf Novae, with average outburst amplitudes of ~4m, which is very similar to the statistics of the MASTER-SAAO results to date. We conclude that the two CV surveys are very similar, with the two samples pushing the limiting magnitude deeper and consequently revealing a somewhat different CV population compared to the brighter systems discovered previously (e.g. from spectroscopic surveys). The mean magnitude of the new CVs found by CRTS is VCSS ~17, with very few system fainter than VCSS ~20. This is likely due to selection effects, where fainter and lower amplitude DNe are more difficult to detect. With MASTER having a similar limiting magnitude to CRTS (VCSS ~20), we believe that the two CV populations discovered by these complementary surveys are therefore quite similar. Now that the SSS (Australia) node of the CRTS has ceased operating, only MASTER-SAAO is continuing to systematically survey the southern skies for new CVs, although more CV discoveries are also following from surveys for other types of transients, for example SNe from the likes of the ASAS-SN survey. The results of two follow-up observations on two CVs were reported, including spectroscopic observations with SALT using Director's Discretionary Time. More detailed papers describing these results and their interpretation are currently in preparation and more intensive SALT follow-up observations of transients has begun, including of new CV discoveries. Finally we discussed the future possibilities of more expansive programs on transient follow-up observations at SAAO, exploiting two new robotic facilities that will become operational during 2016. Our experiences gained in these endeavours will help to inform how to conduct larger scale SALT and SAAO transient follow-up campaigns in the future, for example with the expansive transient programs associated from the SkyMapper, GAIA and LSST missions.