Twinkle, twinkle little star! Here’s how your wonders are
Since the dawn of humanity, the stars in the night sky have captured our imagination as we sing nursery rhymes to children pondering the nature of stars: “Twinkle, twinkle little star, how I wonder what you are”.
Now NASA telescopes are able to probe far into the universe, but astronomers have struggled to ‘see’ inside the stars. Recently with modern space telescopes, astronomers have begun to unlock the interiors of stars by listening to the symphony of sounds that they generate.
Before they explode as supernovae, these blue supergiants or stars are the metal factories of the universe and they produce all chemical elements beyond helium in the Periodic Table of Mendeljev, whose 150-year anniversary will be celebrated this year.
Lead author Dr Dominic Bowman from the KU Leuven Institute of Astronomy, explains: “Before the NASA Kepler/K2 and TESS space telescopes, few blue supergiants that vary in brightness because of waves were known. But if you look at the brightness of an individual star for long enough with a very sensitive detector, you can map out how it changes over time. In asteroseismology – the study of waves inside stars – we use these variations to probe the physical and chemical processes inside the stars.”
The discovery of waves in so many blue supergiant stars was a Eureka moment, says Bowman.
“The variability in these stars had been there all along, we only had to be patient and wait for modern space telescopes to observe them… It is as if the rock-and-roll stars had been performing the whole time, but only now opened the doors of their concert hall because of NASA space missions.
Therefore, it appears that the nursery rhyme sung to children, “Twinkle, twinkle little star, how I wonder what you are” is not so far removed from the reality of modern-day space telescope observations.