It was discovered by William Frederick Denning, an English amateur astronomer, at 09:30 GMT on 20 August 1920, at which time it had a magnitude of 3.7.

V476 Cygni's light curve is quite unusual, showing a rapid decline from maximum brightness, followed by a slow nearly linear fading.

In the case of V476 Cygni, modeling indicates that the white dwarf has a mass of 1.18M⊙, and it is receiving 6×10−10 M⊙ of material from the donor star, per year.

Santamaria et al. examined images of the nebula taken in 1944, 1993 and 2018 and found that the shell is clearly expanding.

[1] Surprisingly, a 1997 attempt to image the shell using the Hubble Space Telescope, was unsuccessful.