Scientists take a deep look into the hearts of stars

Researchers measure the inner structure of distant suns from their pulsations

Scientists take a deep look into the hearts of stars
A glimpse into the heart: Artist's impression of the interior of the star, which was studied through its surface oscillations. © Earl Bellinger / ESA

Our Sun and most different stars, encounter throbs that spread through the star’s inside as sound waves. The frequencies of these waves are engraved on the light of the star and can be later observed by space experts here on Earth. Like how seismologists translate the inward structure of our planet by examining quakes, stargazers decide the properties of stars from their throbs—a field called asteroseismology.

Presently, out of the blue, a point by point examination of these throbs has empowered Earl Bellinger, Saskia Hekker and their partners to quantify the interior structure of two far-off stars.

The two stars they examined are a piece of the 16 Cygni framework (known as 16 Cyg An and 16 Cyg B) and both are fundamentally the same as our own Sun.

Lead author Earl Bellinger said, “Due to their small distance of only 70 light years, these stars are relatively bright and thus ideally suited for our analysis. Previously, it was only possible to make models of the stars’ interiors. Now we can measure them.”

To make a model of a star’s inside, astrophysicists differ stellar development models until the point that one of them fits the watched recurrence range. Be that as it may, the throbs of the hypothetical models frequently vary from those of the stars, in all probability because of some stellar material science as yet being obscure.

Bellinger and Hekker in this way chose to utilize the reverse strategy. Here, they determined the neighborhood properties of the stellar inside from the watched frequencies. This technique depends on less on hypothetical presumptions, yet it requires superb estimation information quality and is scientifically testing.

Utilizing the opposite technique, the analysts looked more than 500,000 km profound into the stars—and found that the speed of sound in the focal locales is more prominent than anticipated by the models.

“On account of 16 Cyg B, these distinctions can be clarified by revising what we thought to be the mass and the extent of the star,” says Bellinger. On account of 16 Cyg A, notwithstanding, the reason for the errors couldn’t be recognized.

It is possible that as-yet-unknown physical phenomena are not sufficiently taken into account by the current evolutionary models.

Bellinger said, “Elements that were created in the early phases of the star’s evolution may have been transported from the core of the star to its outer layers. This would change the internal stratification of the star, which then affects how it oscillates.”

Saskia Hekker, who leads the Stellar Ages and Galactic Evolution (SAGE) Research Group at the Max Planck Institute in Göttingen said, “Ten to twenty additional stars suitable for such an analysis can be found in the data from the Kepler Space Telescope.”

“The inverse method delivers new insights that will help us to improve our understanding of the physics that happens in stars. This will lead to better stellar models, which will then improve our ability to predict the future evolution of the Sun and other stars in our Galaxy.”

Earl P. Bellinger, Sarbani Basu, Saskia Hekker, Warrick H. Ball. Model-independent Measurement of Internal Stellar Structure in 16 Cygni A and B. The Astrophysical Journal, 851 (2), 2017