Special Notice #206: Request for photometry of the dwarf nova SS Cygni

April 21, 2010: Further to AAVSO Special Notice #204 (2010 April 15), we are requesting additional observations of the bright dwarf nova SS Cygni currently in outburst. SS Cyg is currently beginning a dwarf nova outburst, and observations of this star made with the EVLA have detected the source at radio wavelengths. Observations of SS Cyg have been scheduled with the VLBA on 2010 April 22 and April 23. Continued optical monitoring of SS Cyg through the end of the current outburst is strongly encouraged, with intensive coverage requested during the VLBA observations.
According to Dr. Gregory Sivakoff (UVa), SS Cyg was detected by the EVLA at the start of the outburst, and VLBA observations have been scheduled to follow up on this detection and study the evolution of the outburst at radio wavelengths. The observations have been scheduled during the following windows:
2010 April 22, 10:00-18:00 UT (JD 2455308.91 - 309.25)
2010 April 23, 10:00-18:00 UT (JD 2455309.91 - 310.25)
Both visual magnitude estimates and CCD photometry are strongly encouraged. CCD time-series observations are strongly encouraged, particularly in V filter if available. SS Cyg is currently around m(visual) = 9.0, and should remain within a magnitude of that brightness for the next few days. CCD observers should have no trouble obtaining good signal to noise with short exposures.
SS Cyg is located at the following (J2000) coordinates:
RA: 21 42 42.79 , Dec: +43 35 09.9
Customized charts for SS Cyg may be generated using AAVSO VSP: http://www.aavso.org/observing/charts/vsp/index.html?pickname=SS%20Cyg
Please report all observations to the AAVSO using the name "SS Cyg".
This AAVSO Special Notice was prepared by Dr. Matthew Templeton.
Note: the text has been edited to correct the schedule of radio observations, which will be made with the VLBA rather than EVLA.

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