Alert Notice 673: SS Cyg photometry and spectroscopy requested to complement TESS monitoring

July 25, 2019

AAVSO Forum threads (scroll to the bottom of a thread for latest posts):
  -   Campaigns and Observing Reports:
  -   Cataclysmic Variables: ss-cyg-tess-2019-01

Dr. Stella Kafka (AAVSO) has requested multicolor photometry and spectra of the dwarf nova SS Cyg to complement monitoring by the TESS satellite taking place now to mid-September.

Dr. Kafka writes: "With more than 100 years of observations in the AAVSO International Database, SS Cyg is one of the best observed dwarf novae – and one of the most rewarding targets in the night sky. SS Cyg will be observed with TESS from mid-July to mid-September. The TESS dataset will provide uninterrupted observations of the target for about 2 months. This is a unique opportunity to complement satellite data with multi-color ground-based photometric observations and small telescope spectra and uniquely capture quiescence behavior and expected outbursts of the system."

Coverage is requested now through September 2019. Filtered photometry (all filters) is requested. Spectroscopy is also requested. Visual observations are welcome to complement the filtered photometry. SS Cyg (V=8.0~12.4) is currently nearly back at minimum following an outburst that occurred on 2019 July 11.

Coordinates for SS Cyg (J2000): RA 21 42 42.79  Dec +43 35 09.9

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

Optical observations should be submitted to the AAVSO International Database using the name SS CYG.

For information on submitting spectra to the AAVSO Spectroscopy Database, please see the bottom of the AAVSO Spectroscopy Section webpage (

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


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