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CH Cygni

Although Z Andromedae has been observed for slightly longer, the symbiotic star CH Cygni has been more intensely observed and has historically reached brighter limits than the class prototype Z And.  CH Cyg is a fine variable currently varying between magnitude 7 and 11.  The star underwent a prolonged major outburst in the early 1970s and reached magnitude 5 by the early 1980s.  Since 1984, CH Cyg has faded below its historical average around 7th magnitude, and now spends most of its time around magnitude 8.

CH Cyg is also notable for forming an astrophysical jet, caused by the acceleration of accreted material by the compact secondary star.  The jet was first detected in the mid-1980s, and was caused by the major outburst of the 1970s.  The jet formation was caught again in 1996 by Margarita Karovska and collaborators following another outburst.

For more information visit: /vsots_chcyg
Prepared By: Matthew Templeton
AAVSO 49 Bay State Rd. Cambridge, MA 02138 aavso@aavso.org 617-354-0484