NML Cygni, is a Red Hypergiant star, currently the largest know, and one of the most luminous in the Galaxy.
Something is missing from your question. Cygni is not a star. The constellation name is Cygnus. The star will have a name like Alpha Cygni or 25 Cygni.
Cygni is a star system in the Cygnus constellation. The primary star, Cygni A, is a blue-white star with a temperature around 19,000 K. The companion star, Cygni B, is a yellow-white star with a temperature around 8,500 K.
4200
The Earth is about 11.4 light years away from the binary system cygni. Cygni is not the name of a star. It refers to the constellation cygnus (the swan), and is used in the names of stars and other objects within that constellation. For example, the system 61 cygni and the star gamma cygni. The constellation doesn't have a single distance from the earth because the objects of which it is made are all at different distances. For example, the brightest star in the constellation, referred to as alpha cygni, is at a distance of 1630 light years, while gamma cygni, the third brightest star in the constellation, is at a distance of about 1800 light years. 61 cygni on the other hand is only about 11 light years from earth.
NML Cygni, is a Red Hypergiant star, currently the largest know, and one of the most luminous in the Galaxy.
Chi Cygni is a variable star, meaning its brightness varies cyclically. Chi Cygni's temperature is typically given as 3000 K.
The temperature of Cygni, or specifically the star Deneb (also known as Alpha Cygni), is estimated to be around 8,500 Kelvin. This makes it a very hot and luminous star compared to our Sun, which has a surface temperature of about 5,500 Kelvin.
4 200*C
Gamma Cygni, also known as Sadr, is approximately 1,800 light-years away from Earth.
T. Tomov has written: 'CH Cygni, spectroscopic data for the period 1981-1985' -- subject(s): CH Cygni, Observations, Spectra
Cygni refers to the constellation Cygnus (the swan). Cygnus comprises tens of stars - not just one. These are of different magnitude and so the question is meaningless.
Which one - there are hundreds of stars in the Cygnus constellation