We know a lot about the stars. After centuries of telescopes targeting the night sky, astronomers and amateurs alike can discover important properties, such as the mass or structure of any star.

“The sun. It’s the only star we know of, ”said David Soderblom, an astronomer at the Baltimore Space Telescope Science Institute. “Everything else counts from there.”

Calculations and indirect measurements based on physics The age of a star I can give astronomers figures. Some methods work best for different types of stars. Here are three ways astronomers can estimate the age of a star.

Diagram Hertsprung-Russell

In the early twentieth century, two astronomers – Egner Hertsprung and Henry Norris Russell – came up with the idea of ​​representing temperature according to the brightness of the stars. Models of these Diagram Hertsprung-Russell, Or HR, is related to where the different stars were in that life cycle. Today, scientists use these models to determine the age of galaxies, which are thought to have formed at the same time.

Rotation rate

By the 1970s, astronomers observed a trend: stars in younger groups were moving faster than stars in older groups. In 1972, astronomer Andrew Schumanich proposed a simple equation for calculating the age of a star using the rotation rate and surface activity of the star: rotation rate = (age) -½.

This is a method used by individual players for decades. But some stars do not seem to slow down when they reach a certain age. Instead, they maintain the same rotational speed throughout life.

“Rotation is the best thing to use for stars younger than the Sun,” say astronomers.

For stars older than the Sun, other methods are better.

Stellar seismology

New data confirming the rotation rate is not the best way to estimate the age of an individual star, but from an unlikely source: the Kepler space telescope hunting for exoplanets. Not only was Kepler a breakthrough in exoplanet research, it also brought astronomical geography to the forefront of observing the same stars for a long time.

Observing the lightning of a star gives clues about its age. Scientists view changes in the brightness of a star as an indicator of what is happening below the surface, and estimate the approximate age of the star through modeling. To do this, the Kepler telescope needs a very large set of data about the brightness of the star it can provide.