VY Canis Majoris
VY Canis Majoris (VY CMa) is a red hypergiant star in the constellation Canis Major. It is about 1.2 kiloparsecs (3,900 light-years) distant from Earth. It is one of the largest known stars, and one of the most luminous of its type.
VY Canis Majoris is 1,420 times wider than the Sun. If placed at the center of the Solar System, VY Canis Majoris's surface would extend beyond Jupiter's orbit. Other estimates of the radius make it larger than the orbit of Saturn.
VY CMa is a single star, a "semiregular" variable with a period of about 2,001 days. It has an average density of 5 to 10 mg/m3.
- Wittkowski M. et al 2012. Fundamental properties and atmospheric structure of the red supergiant VY CMa based on VLTI/AMBER spectro-interferometry. Astronomy & Astrophysics 540: L12. 
- Massey, Philip; Levesque, Emily M.; Plez, Bertrand (2006). "Bringing VY Canis Majoris down to size: an improved determination of its effective temperature". The Astrophysical Journal 646 (2): 1203–1208. doi:10.1086/505025.