VY Canis Majoris

VY Canis Majoris

VY Canis Majoris (abbreviated to VY CMa) is a pulsing variable star 1.2 kiloparsecs (3,900 light-years) from the Solar System in the somewhat southern constellation of Canis Major. It is an extreme oxygen-rich (O-rich) red hypergiant (RHG) or red supergiant (RSG). It is one of the most massive and bright red supergiants known, as well as one of the most brilliant stars in the Milky Way.

There is no indication that it is part of a multiple star system. At wavelengths of 5 to 20 microns (m), its large infrared (IR) excess makes it one of the brightest objects in the local section of the galaxy, indicating a dust shell or heated disc. It has a mass of around 178 times that of the Sun (M). Because of its mass loss, it is surrounded by a complicated asymmetric circumstellar envelope (CSE). It was one of the earliest radio masers identified and generates powerful molecular maser emission. VY CMa is located inside the massive molecular cloud Sh2-310, a star-forming H II zone with a diameter of 480 arcminutes (′) or 681 light-years (209 pc).

Size and volume of VY Canis Majoris

VY Canis Majoris has a radius of around 1,420 times that of the Sun (R), which is close to the predicted maximum, the Hayashi limit, which has a volume of approximately 8 billion times that of the Sun. If this mid-point estimate is right, a quantum of light travelling at the speed of light would take 6 hours to traverse around its surface, whereas the Sun takes 14.5 seconds. If this star were to take the place of the Sun, its surface would lie outside Jupiter's orbit, according to this estimate.

UV Scuti vs VY Canis Majoris

VY Canis Majoris pulses similarly to UY Scuti. VY Canis Majoris, on the other hand, has a solar radii range of 1300 to 1540. It has a radius of 613,850,000 miles on average (987,895,800 kilometers).

VY Canis Majoris may be bigger than UY Scuti based on these figures, but UY Scuti is the larger star on average.

Posted By InnoTechzz