From Stellar Evolution, by Don Scott:

 

The star FG Sagittae breaks all the rules of accepted stellar evolution. FG Sagittae has changed from blue to yellow since 1955! It, quite recently, has taken a deep dive in luminosity. FG Sagittae, is the central star of the planetary nebula (nova remnant?) He 1-5. It is a unique object in the sense that for this star we have direct evidence of stellar evolution but in a time scale comparable with the human lifetime. [CCD Astronomy, Summer 1996, p.40.] "Around 1900 FG Sge was an inconspicuous hot star (T = 50,000 K) of magnitude 13. During the next 60 years it cooled to about 8000 K and brightened in the visual region to magnitude 9, as its radiation shifted from the far-UV to the visual region. Around 1970 a whole new bunch of spectral lines appeared due to elements such as Sr, Y, Zr, Ba and rare earths. .... The star cooled further in the 1970s and 80s and then all of a sudden in 1992 its magnitude dropped to 14. Further drops occurred from 1992 to 1996 with a very deep minimum near magnitude 16 in June of 1996."

 

So, after abruptly brightening by four magnitudes, it has dropped seven magnitudes. From the end of the last century FG Sagittae has moved across the HR diagram changing from a normal hot giant to a "late spectral type" (cool) star with marked changes in its surface chemical composition. Its present surface temperature is in the range of 4000K. This is not the kind of slow stellar 'evolution' mainstream astrophysicists preach.

 

And FG Sagittae is a binary pair!

 

The official wording was, "In 1995 FG Sge changed in brightness in a quite sporadic manner from V~10.5 to ~13.0 according to the data by Hungarian Astronomical Association-Variable Star Section. During the spectral observations on 9/10 and 10/11 August, FG Sge was very faint (HAA-VSS data: V~12.5-13.0, according to Variable Stars Observers' League of Japan: ~13.3) and therefore erroneously the visual companion 8'' apart from FG Sge was actually observed. This is probably the first high resolution spectrum of the companion ever obtained. The spectrum turned out to correspond to a quite normal giant with the spectral type around K0."

 

Is FG Sagittae an example of the binary fissioning (caused by electrical stress) that was described above? It seems to have all the basic characteristics: nova-like brightening followed by loss of luminosity and loss of temperature - moving to a different spectral type with marked changes in its surface chemical composition, discovery of a binary companion, and the entire systems lies within a nebulous nova remnant.