Alert Notice 858: SS Cyg monitoring requested

Note: SS Cyg is going into outburst - please be sure to monitor this target throughout this outburst and after it returns to minimum.  -  Elizabeth O. Waagen, June 3, 2024

April 2, 2024

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
- Campaigns and Observation Reports:
- Cataclysmic Variables:

Please subscribe to these threads if you are participating in the campaign so you can be updated by the astronomer and by HQ. Join in the discussion or ask questions there!

Dr. Mariko Kimura (Kanazawa University) requests AAVSO assistance in monitoring the cataclysmic variable SS Cyg over the coming several months in support of target-of-opportunity observations with the XRISM satellite.

Dr. Kimura writes: "I would like to ask for daily monitoring of SS Cyg for X-ray observations by XRISM. XRISM is the X-ray satellite capable of obtaining high-resolution energy spectra and highly time-resolved light curves, which was launched in 2023 by JAXA. SS Cyg is one of the most important targets to verify the performance of XRISM, and the XRISM team will observe it during optical outburst. We have to trigger observations as soon as possible if this object enters a new outburst within the next 4 months. I know AAVSO observers continue to monitor this object, but we need daily monitoring not to miss the best opportunity from April to early August."

Nightly V and Rc CCD and PEP observations are requested beginning now and continuing through August. Visual observations (not more than one per night for this campaign) are welcome. If for any reason the campaign is concluded earlier than August, observers will be notified via the forum threads given above, so please subscribe to stay informed.

SS Cyg has a V range of 7.7-12.4. The most recent observations in the AAVSO International Database indicate that SS Cyg was at CV magnitude 11.834 +/-0.091 on 2024 Apr. 02.19405 UT (A. de Oliveira Kovacs, Sao Paulo, Brazil), and at V magnitude 12.037 +/- 0.010 on Mar. 31.39346 UT (J. Backman, Lappeenranta, Finland).

Coordinates (J2000): R.A. 21 42 42.79  Dec. +43 35 09.9 (from VSX entry for SS Cyg)

Charts with comparison stars for SS Cyg may be created using the AAVSO Variable Star Plotter (VSP).

Please report all observations to the AAVSO International Database using the name SS CYG.

This AAVSO Alert Notice was prepared by Elizabeth O. Waagen.


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