VY Canis Majoris

≈ 500,000 L ☉

VY Canis Majoris (VY CMa ) is a red hyper- giant. This star is one of the biggest stars, whose size is known or estimated, and perhaps one of the most luminous stars in our Milky Way.

Properties

Roberta M. Humphreys calculated in 2006, the radius of VY CMa on the 1800 - to 2100 - times the solar radius. If our sun replaced by such a star, then its surface would extend to the orbit of Saturn. So that its diameter is approximately 200,000 times as large as that of the earth, that is about 2.5 billion km. To illustrate: A plane flying with 800 km / h would need about 350 years to put this distance. A further comparison: If the earth has a diameter of 1 mm, then the sun would have a diameter of about 10.9 centimeters and VY Canis Majoris a diameter of 200 meters.

The distance from the Earth to VY CMa is about 1500 parsecs ( 4900 light-years, 47 trillion km).

Recent studies from the year 2012 indicate a smaller radius of 1420 ± 120 R ☉.

There are two different opinions on the assignment of VY CMa: Some researchers (such as Roberta M. Humphreys in their work ) find that the star is a very large and very bright red supergiant. Other ( the investigation of Massey, Levesque and Plez ), however, come to the conclusion that VY CMa is just a normal red supergiant.

The part of the name " VY " follows the rules for naming variable stars and states that VY Canis Majoris is the 43 variable star, which was discovered in the constellation Canis Major.

2007 discovered American astronomers around Lucy Ziurys in studies with a 10- meter radio telescope hydrogen cyanide, carbon disulfide, sodium chloride, and phosphorus -nitrogen compounds in the vicinity of the star. This surrounding cloud is also the reason why only a fraction of the outgoing from the star visible light reaches us and VY CMa therefore appears much darker than would be predicted on the basis of its luminosity.