Cygnus OB2 #12 is generally assumed to be a member of the Cyg OB2 Association, a cluster of young massive stars about 4,600 light-years (1,400 pc) away in Cygnus, and resides in a region of the Milky Way from which visible light is heavily absorbed by interstellar dust when viewed from Earth.
[11] If the closer distance were accepted then the star would be a more conventional blue supergiant with a luminosity around 440,000 L☉, a radius of 118 R☉, and a current mass of 25 M☉.
[1] However using the distance provided by Gaia EDR3 it was determined in one work that the star has a luminosity of only about 316,000 L☉, a radius of about 100 R☉, and a mass much lower than the currently accepted ~110 M☉.
It shows brightness variations of a few tenths of a magnitude, but these do not seem to be associated with colour changes that would be expected from an LBV.
[7] If the lower Gaia DR2 distance were correct then the properties of Cygnus OB2 #12 would mean it would be expected to pulsate at low amplitude with a period of a few days.