Blue supergiants are rock-and-roll: they live fast and die young. This makes them rare and difficult to study. Before space telescopes were invented, few blue supergiants were observed, so our knowledge of those stars was limited. Based on the NASA Space Telescope data, an international team around KU Leuven examined the sounds that emerged in these stars and discovered that almost all blue supergiants shimmer in brightness due to waves on their surface.
The night sky has taken our imagination. We even sing nursery rhymes for children who think about the nature of the stars: "sparkle, sparkle little star, how do I wonder what you are". Telescopes can penetrate far into the universe, but astronomers have difficulty "seeing" the stars. New space telescopes enable astronomers to "see" the waves that arise in the deep interior of the stars. This makes it possible to study these stars with the help of asteroseismology, a method similar to how seismologists use earthquakes to study the interior of the earth.
Stars come in different shapes, sizes and colors. Some stars are similar to our sun and have been quiet for billions of years. More massive stars born ten times the mass of the Sun live significantly shorter and more actively before they explode and expel their material into space in a so-called supernova. Blue super giants belong to this group. Before they explode, they are the metal factories of the Universe, as these stars in the Mendeleev Periodic Table produce the most chemical elements besides helium.
For the first time, researchers were able to "see" blue supergiants under the opaque surface of. "The discovery of waves in so many blue supergiant stars was a eureka moment," says postdoc researcher Dominic Bowman, who is the corresponding author for this study: "The flicker in these stars has always been there, we just had to go to the Modern space telescopes are waiting to be watched: it's as if the Rock'n'Roll stars have been playing all the time, but only now NASA space missions have been able to open the doors of their concert hall ̵
" Before the NASA Kepler / K2 and TESS Space Telescopes Only a few blue supergiants were known that differed in their brightness, "says Bowman (KU Leuven). "So far, we had not seen those waves that led to shimmer and glitter on the surface of blue supergiants – you need to be able to look at the brightness of a single star long enough with a very sensitive detector before you can figure out what it looks like of time. "
Therefore, it seems that the nursery rhyme that sang to the children," Sparkle, sparkle, little star, how I'm wondering what you are, "is not that far from the reality of today's space telescope observations , "We are now in a golden age of asteroseismology of hot massive stars thanks to modern space telescopes, and the discovery of these waves in blue supergiants allows us to examine the precursors of supernovae from a new perspective," concludes Bowman.
Materials provided by KU Leuven . Note: Content can be edited by style and length.