\n\n \n Artist ‘s impression of sound waves (p modes), with different frequencies, traveling across the inner layers of a star. Credit: Tania Cunha (Planet\u00e1rio do Porto\u2014Centro Ci\u00eancia Viva)\/Instituto de Astrof\u00edsica e Ci\u00eancias do Espa\u00e7o) \n <\/figcaption><\/figure>\n<\/p><\/div>\n<\/div>\n
At a distance of 11.9 light years, Epsilon Indi (\u03b5 Indi) is an orange dwarf star (also known as a K dwarf) with 71% of the sun’s diameter. An international team, led by Instituto de Astrof\u00edsica e Ci\u00eancias do Espa\u00e7o (IA) researcher Tiago Campante, studied this star with the ESPRESSO spectrograph, mounted at the European Southern Observatory’s (ESO) Very Large Telescope (VLT), and detected the tiniest “starquakes” ever recorded.<\/p>\n\n <\/p>\n<\/section>\n
The team used a technique dubbed asteroseismology, which measures oscillations in stars. These provide indirect glimpses of stellar interiors, just as earthquakes tell us about Earth’s interior. In \u03b5 Indi, the peak amplitude of the detected oscillations is just 2.6 centimeters per second (about 14% of the sun’s oscillation amplitude), which makes it the smallest and coolest dwarf star observed to date with confirmed solar-like oscillations.<\/p>\n
These measurements are so precise that the detected speed is slower than the average speed of a sloth.<\/p>\n
“The extreme precision level of these observations is an outstanding technological achievement. Importantly, this detection conclusively shows that precise asteroseismology is possible down to cool dwarfs with surface temperatures as low as 4,200 degrees Celsius, about 1,000 degrees cooler than the sun’s surface, effectively opening up a new domain in observational astrophysics,” comments Campante, assistant professor at the Dept. of Physics and Astronomy of the Science Faculty of the University of Porto (DFA-FCUP).<\/p>\n\n \n \n \n \n \n <\/p>\n