March 26, 2024
Tiniest ‘starquakes’ ever detected
An international team of researchers, led by Tiago Campante from the Instituto de Astrofísica e Ciências do Espaço (IA), has made a groundbreaking discovery in the field of astrophysics. Using the ESPRESSO spectrograph at the European Southern Observatory’s (ESO) Very Large Telescope (VLT), the team detected the tiniest ‘starquakes’ ever recorded in the orange dwarf star Epsilon Indi (ε Indi), located 11.9 light years away.
The technique used, called asteroseismology, allowed the researchers to measure oscillations in the star, providing indirect insights into its interior. This breakthrough marks the first confirmed detection of solar-like oscillations in a cool dwarf star with a surface temperature as low as 4,200 degrees Celsius, approximately 1,000 degrees cooler than the sun’s surface.
The precision of these observations is unprecedented, with the detected oscillations reaching a peak amplitude of just 2.6 centimeters per second, which is about 14% of the sun’s oscillation amplitude. To put this in perspective, the speed of these oscillations is slower than the average speed of a sloth, highlighting the remarkable technological achievement of the research team.
Campante, an assistant professor at the Dept. of Physics and Astronomy of the Science Faculty of the University of Porto (DFA-FCUP), emphasized the significance of this discovery, stating, “This detection conclusively shows that precise asteroseismology is possible down to cool dwarfs, effectively opening up a new domain in observational astrophysics.”
Furthermore, the team’s findings have the potential to address a long-standing disagreement between theoretical predictions and observational data regarding the relation between the mass and diameter of cool-dwarf stars. By studying the oscillations in K dwarfs through asteroseismology, scientists aim to identify and rectify the deficiencies in current stellar models, ultimately eliminating the existing discrepancies.
This groundbreaking research not only expands our understanding of stellar interiors but also paves the way for advancements in astrophysical observations and modeling, shaping the future of astrophysics.
Artist’s impression of sound waves (p modes), with different frequencies, traveling across the inner layers of a star. Credit: Tania Cunha (Planetário do Porto—Centro Ciência Viva)/Instituto de Astrofísica e Ciências do Espaço
