Yes, It is is the largest star discovered to date, the fact that we can see it is why we know about it.
VY Canis Majoris is about 4,900 light years from earth.
It is difficult to predict exactly when Canis Majoris, or Betelgeuse, will go supernova. It is expected to happen within the next 100,000 years, but could occur sooner or later. When it does happen, it is likely to be a spectacular event visible from Earth.
VY Canis Majoris cannot be seen from Earth with the naked eye. It is a red supergiant star located about 3,900 light-years away in the constellation Canis Major, and its apparent magnitude is around 8.9, which is too dim for unaided vision. Only through telescopes can it be observed, typically as a faint point of light.
VY Canis Majoris is kinda beside Wezen(Delta Canis Majoris.) Find where it says VY
Canis Major is a constilation. Cy canis majoris is a star.
VY Canis Majoris (Not Canis Majoris)
VY Canis Majoris has an absolute magnitude of -9.4.
A day on VY Canis Majoris is estimated to be around 1.5 Earth years due to its slow rotation.
As of today (2009) there is no star larger than VY Canis Majoris - a galaxy is larger than VY Canis Majoris though.
Canis Major
Scientists say that VY Canis Majoris is the biggest star we know so basically VY Canis Majoris is bigger than Kolob.
As far as mass goes, R136a1 beats out VY Canis Majoris by 253 solar masses (265 solar masses for R136a1 vs Canis Majoris' 30). However, VY Canis Majoris beats out R136a1 in radius by about 1,385 solar radii (Canis Majoris is 1,420 solar radii vs R136a1's ~35).