Special Notice #414: SS Cyg monitoring continues for radio campaign

April 5, 2016: Further to AAVSO Alert Notice 536, close monitoring of the cataclysmic variable SS Cyg is urgently requested. Immediate notification of the beginning of the anticipated outburst is crucial and is requested.

The success of the multiwavelength (radio and optical) observing campaign on SS Cyg underway depends on immediate reporting of outburst behavior to trigger multi-site radio observations.

In addition to triggering multi-site radio observations of SS Cyg in research on radio emission from this dwarf nova, AAVSO observations are used for correlation with the radio data during analysis.

Dr. James Miller-Jones writes: "As we decided a month or so ago, the anomalous/slow-rise outburst that eventuated last time around was not conducive to accurate triggering of our approved e-MERLIN radio observations. We therefore decided to hold off on triggering e-MERLIN until the next outburst, which should be beginning at some stage over the next week or so. We will once again have full AMI-LA radio coverage, but this time the e-MERLIN observations should provide both higher sensitivity and higher resolution at three epochs during the outburst. We are also requesting much denser Swift X-ray coverage of the rise and decay phases.

"Given all that, might the AAVSO be able to provide good coverage of the upcoming SS Cyg outburst? While getting the trigger notification as early as feasible is our most immediate concern, so that we can alert Swift, AMI and e-MERLIN, we would also be very grateful for good optical monitoring of the full outburst..."

Please keep a very close watch on SS Cyg. Visual and CCD/DSLR (particularly V) observations are requested (no time series unless outburst is underway and radio observations have been triggered). Its normal minimum magnitude is ~11.8 V, but it can fluctuate to around 11.5. If it becomes brighter than 11.5 V, it could well be going into outburst. If it reaches 11.0, it is almost certainly on its way up.

Please report your observations of SS Cyg to the AAVSO as soon after you make them as possible. If you see it 11.5 or brighter, please report them immediately.

Coordinates: RA 21:42:42.8  Dec. +43:35:10  (2000.0)

AAVSO finder charts for SS Cyg with comparison stars may be generated using the AAVSO Variable Star Plotter (VSP).

Please submit your observations to the AAVSO International Database using the name 'SS CYG'.

This AAVSO Special Notice was compiled by Elizabeth O. Waagen.


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