HOW BIG IS ANTARES?

Using the best radio telescopes in the world, this local red supergiant star has recently been mapped in extraordinary detail

- Lee Cavendish

The night sky, especially when viewed from an area with low to no light pollution, can reveal a beautiful array of celestial gems – twinkling stars that generations before have marvelled at. The difference between then and now is that our generation has the capability to map these stars with precision. New research has taken this to a whole new level by mapping the famous star Antares, learning more about its atmosphere and how this can be applied to other red supergiant stars.

Throughout the years people have gazed upon ruddy Antares, the brightest star in the constellation of Scorpius and one of the brightest stars in the night sky, which lies 554 light-years from Earth. As telescopes, spectroscopy and multi-wavelength observations have become more advanced, we have been able to learn more about the stars. Scientists have been able to categorise Antares as a red supergiant star that has swollen as it approaches the end of its life, despite it being only 11 million years old. By comparison the Sun is 4.6 billion years old. This is because Antares weighs 12 solar masses – 12 times the mass of our Sun – and with stars the biggest and brightest burn out the quickest. Astronomers have deduced over many years of visible-light observations that Antares is approximately 700-times wider than the Sun, and previous research into its climate has suggested that the temperature of the red supergiant star’s chromosphere should be between 5,700 and 12,700 degrees Celsius (10,000 and 22,900 degrees Fahrenheit).