With data from the Kepler (NASA), Gaia (ESA) and SOHO (NASA/ESA) satellites, a employees, led by Instituto de Astrofísica e Ciências do Espaço (IA) researcher Ângela Santos, seems to have put an end to the idea the sun is probably not an on a regular basis “sun-like” star. The outcomes have been revealed within the current day (April 6) in Astronomy & Astrophysics.
Although it’d sound odd to try to find out if the sun is a sun-like star, Ângela Santos, a researcher at IA, explains the problem: “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. 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,” offers Santos.
For this work, the employees chosen numerous stars with comparable properties to the sun. The employees used a model new stellar properties catalog, from Kepler data, plus some Gaia data and the employees’s rotation period and magnetic train index catalog. The stellar data have been in distinction with data of train from the ultimate two solar cycles, from the VIRGO/SPM instrument aboard the SOHO spacecraft.
One of the studied stars, chosen from the Kepler catalog, was lovingly named Doris by the astronomers. In a earlier work, the employees had already observed that Doris’ cycle amplitude was twice that of the sun for the latest solar cycles, even supposing Doris has comparable properties to the sun. Santos says, “The difference was the metallicity. Our interpretation is that the effect of metallicity, which leads to a deeper convection zone, produces a more effective dynamo, which leads to a stronger activity cycle.”
For this work, when the employees chosen stars identical to Doris, with out considering metallicity inside the selection, they found an additional of extreme metallicity stars. “In our selection, the only parameter that could lead to this excess is the rotation period. In particular, Doris had a longer period than the sun. And, in fact, we found evidence of a correlation between the rotation period and metallicity,” says Santos.
The two analysis have fixed outcomes, because of stronger magnetic activity signifies that the magnetic braking course of ends in a slower rotation period, which explains why Doris rotates slower than the sun, no matter being very comparable and barely youthful than the sun.
Ângela Santos says, “What we found is that although there are stars which are more active than the sun, the sun is indeed a completely normal sun-like star.”
A.R.G. Santos et al, Temporal variation of the photometric magnetic train for the Sun and Kepler solar-like stars, Astronomy & Astrophysics (2023). DOI: 10.1051/0004-6361/202245430
Institute of Astrophysics and Space Sciences
The sun is an ordinary star in any case, confirms analysis (2023, April 6)
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