The sun has been “sleeping” for 9,000 years and weaker than similar stars in our galaxy.

A new study revealed that the sun, while the most important source of energy for life on Earth, is “a little sleepy” compared to other stars in the universe.

Astronomers at the Max Planck Institute in Germany compared the sun to hundreds of similar stars, using data from NASA’s Kepler Space Telescope, and the researchers chose stars with a surface temperature, age, and spin similar to the Sun in the Milky Way.

The researchers say it is unclear if the sun has been “going through a quiet period” for 9,000 years or if it is less bright than other similar stars.

“We were very surprised that most sun-like stars are much more active than the sun,” said Dr. Alexander Shapiro of the Max Planck Institute.

Scientists reduced the first sample of candidates from the measurement data recorded by Kepler, opted to look at the stars with rotation periods ranging from 20 to 30 days (the sun’s rotation period is 24.5 days), and identified 369 stars comparable to the sun in color, mass, composition, age, temperature and average rate. Rotation, then compared the change in brightness of those stars as Kepler recorded with the change in the brightness of the sun.

The results showed that the sun is very weak, compared to most other stars, about five times.

“It is possible that the sun has gone through a quiet phase for thousands of years and therefore we have a distorted image of our star,” said Dr. Timo Reinhold, first author of the new study.

According to the researchers, the extent of solar activity, and therefore the amount of sunspots, can be reconstructed using scale methods.

The researchers were able to observe ancient records of our star’s activity for 9,000 years, and said that it remained somewhat uniform during that period.

“Compared to the total age of the sun, 9,000 years is like the blink of an eye,” said researchers at the Max Planck Institute. This makes sense when you remember that our star is approximately 4.6 billion years old.

Since there is no way of knowing how active the Sun was in early times, scientists can only turn to the stars for comparison.

The Max Planck researchers, in cooperation with colleagues from the University of New South Wales in Australia and the College of Space Research in South Korea, investigated whether the sun behaved “normally” compared to other stars.

“The speed at which a star rotates around its axis is a critical variable,” explains Dr. Sami Solanki, director of the institute and co-author of the publication.

Solanki says that this rotational speed contributes to the creation of his magnetic field, which is “the driving force responsible for all fluctuations in activity.”

He added: “The state of the magnetic field determines the number of times the sun sends active radiation and the particles receive at high speeds in space in violent explosions, the number of dark sunspots and bright areas on its surface, and therefore , also the brightness of the sun. “

It is unclear why the sun is less active, and researchers say our sun may differ from similar stars in ways that science has not recognized or explained to date.

Source: Daily Mail