The Largest Star in the Universe – Size Comparison Stephenson 2-18

Stevenson 2-18, also known as RSG C2-18, is the largest known star, surpassing UY Scuti. It is a red supergiant with a volume about 10 billion times greater than the Sun. If placed in our solar system, its photosphere would extend beyond Saturn's orbit. Discovered by Charles Bruce Stevenson in 1990, it is located in the constellation of Scutum, approximately 20,000 light-years from Earth. Stevenson 2-18 shines with 440,000 solar luminosities and has an effective temperature of 3200 Kelvin.

What is the name of the largest known star, which is a red supergiant?

• VY Canis Majoris

• UY Scuti

• Stevenson 2-18

• Betelgeuse

If Stevenson 2-18 were to replace the Sun, how far would its photosphere extend?

• Beyond the orbit of Mars

• Beyond the orbit of Jupiter

• Beyond the orbit of Saturn

• Beyond the orbit of Neptune

Who discovered Stevenson 2-18 and in what year?

• Edwin Hubble in 1923

• Charles Bruce Stevenson in 1990

• Carl Sagan in 1980

• Neil deGrasse Tyson in 2005

How far is Stevenson 2-18 from Earth?

• 20,000 light years

• 25,000 light years

• 10,000 light years

• 15,000 light years

What is the estimated effective temperature of Stevenson 2-18?

• 5,800 Kelvin

• 4,500 Kelvin

• 3,200 Kelvin

• 2,500 Kelvin