Astronomers have made a ground-breaking discovery: there may be a little discrepancy between the Sun’s estimated size, the star at the heart of our Solar System.
It is thought that the Sun’s radius is a few hundredths of a percent smaller than what previous analyses suggested. Though this may not seem like much, it might have a big impact on how scientists perceive the celestial body that supports life on Earth.
The preprint publication presenting these results was made available on arXiv, potentially signaling a paradigm shift in our knowledge of the composition and behavior of the Sun.
The new results, which are presently undergoing peer review, are based on sound waves called “pressure” or “p-modes” that are produced and trapped inside the heated plasma interior of the Sun. These resonance sounds may offer information regarding pressure variations taking on in the solar intestine.
According to astronomers Douglas Gough of Cambridge University and Masao Takata of the University of Tokyo, p-mode oscillations provide a “dynamically more robust” picture of the Sun’s interior than other oscillating sound waves. To understand this, visualize the Sun as a bell that is constantly ringing and being struck by many tiny grains of sand.
Scientists can measure the millions of oscillating sound waves, or “modes,” produced by this seismic activity remotely. P-waves, g-modes, and f-modes are a few of these modes; each offers particular insights into the properties and behavior of the Sun.
Since f-modes do not reach the edge of the Sun’s photosphere, some astronomers contend that they are not totally dependable for determining the seismic radius of the Sun. Rather, it seems as though they touch what Takata and Gough call a “phantom surface” with their bounce. However, because P-modes are less sensitive to magnetic fields and turbulence in the Sun’s upper convection zone, they can reach farther.
Takata and Gough support basing the Sun’s size on seismic measurements using p-modes. Based solely on p-mode frequencies, their computations indicate that the solar photospheric radius is minuscule in comparison to the mainstream solar model. Even with the tiny inaccuracy, astronomer Emily Brunsden told New Scientist that it would take a substantial effort to modify the conventional model to account for these results.
“Understanding the reason for the variation is tough because there’s just a lot of different things going on,” she stated to New Scientist.