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CH Cygni Precipitous Fading

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ocn's picture
CH Cygni Precipitous Fading

Hi Everyone,

The symbiotic star CH Cyg appears to be undergoing a fading and reddening event with increasing rapidity. The decline amplitudes between April 17 and June 28 2018 as measured from 3 sets of UBV observations made during that time interval appear to be greatest in U (2.0 magnitudes), followed by B (1.6 magnitudes), and finally in V (0.9 magnitudes). The U-B index appears to have decreased from -0.5 to -0.1 during this interval while B-V has increased from +0.5 to +1.2. Looking at observations submitted just in the past few days suggests the rate of fading has increased substantially. Might the hotter, bluer components of this complexed system be undergoing a partial or total eclipse by the semi-regular red giant secondary ? More observations are planned.




weo's picture
Alert Notice 639 on CH Cyg

AAVSO Alert Notice 639 requests coverage of the symbiotic variable CH Cyg during and after its current fading. Please see the notice for details and observing instructions.

Many thanks, and Good observing,

Elizabeth O. Waagen, AAVSO HQ

CH CYG Visual


Date 2.07.2018, 20:57 UT,Visual CH Cyg 7.5 mag,Binocular Celestron 20x80,Smardzowice (Poland) Code: JDAA 

CH Cyg

CH Cyg,

7.0 mag (visual) 13.07.2018,20.48 UT. Binocular 20x80,Smardzowice,Poland.

dhdeangelis's picture
Precipitous fading or hiccup?

It seems that CH Cyg is recovering, perhaps as fast as it dimmed by about a magnitude two weeks ago. This is interesting!

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