The Sun Is Just a ‘Normal Star’: Says New Study From Kepler, Gaia Satellite

The Sun is just a "normal star" after all, as confirmed by a team of researchers led by Instituto de Astrofísica e Ciências do Espaço (IA) researcher Ângela Santos.

The team used data from the Kepler (NASA), Gaia (ESA), and SOHO (NASA/ESA) satellites to study stars with similar properties to the Sun and found that the Sun is not an anomaly in terms of its magnetic activity.

Is the Sun a 'sun-like' star?

The study aimed to settle the ongoing debate in the scientific community about whether the Sun is a "sun-like" star. Previous studies suggested that stars similar to the Sun were significantly more active, but the team found that the problem was with the stars classified as sun-like, not the Sun itself.

"In the community, there is an ongoing debate on whether the sun is a 'sun-like' star. In particular, about its magnetic activity, several studies suggested that stars similar to the Sun were significantly more active," Ângela Santos, a researcher at IA, said in a press release statement.

"However, the problem doesn't seem to be with the sun, but with the stars classified as sun-like, because there are several limitations and biases in the observational data and the inferred stellar properties."

The team selected several stars with similar properties to the Sun. It used a new stellar properties catalog from Kepler data, some Gaia data, the team's rotation period, and magnetic activity index catalog to compare the stellar data with activity from the last two solar cycles from the VIRGO/SPM instrument aboard the SOHO spacecraft.

The scientists gave the star they were studying the name "Doris." Even though Doris and the Sun have similar features, the scientists previously found that Doris' cycle amplitude was twice that of the Sun for the most recent solar cycles.

According to the team's findings, the difference was due to metallicity, which results in a deeper convection zone and a more powerful dynamo, resulting in a greater activity cycle,

There were too many stars with high metallicities when the team chose stars like Doris without considering the metallicity rotation period was the sole factor that might cause this excess.

Proof of Connection

They discovered proof of a connection between the rotation period and metallicity and discovered that Doris had a longer period than the Sun.

The team's two studies yielded consistent findings, demonstrating that the Sun is a normal sun-like star despite the existence of stars that are more active than it.

The magnetic activity of stars impacts the magnetic braking process and results in a slower rotation period. This explains why Doris rotates more slowly despite being relatively similar to and a little younger than the Sun.

Overall, the study settles the debate about the Sun's classification as a sun-like star. The Sun is a completely normal sun-like star, and the team's findings provide a better understanding of the behavior of stars with similar properties.

The team's findings were published in the journal Astronomy & Astrophysics.