August 23rd 1920
N.V Ginori in Florence, Italy, visual observations of the spectrum of Nova Cygni 1920 were made with a McClean star spectroscope mounted on a 9 inch Cooke equatorial refractor. The spectrum was continuous with dark H/3 just visible. Subsequent observations on August 25th, 26th, 27th, 28th, September 1st, 3rd, 8th, and 11th record the changes in intensity of the hydrogen and enhanced metallic lines.
Nova Cygnus was discovered by William Denning in Bristol on August 20th 1920 at magnitude 3.5.