video: In a young region like the Christmas tree cluster, star formation is still going on. Once the star becomes optically visible, it is "born" (bottom right) and named a pre-main sequence star. During its further evolution, the star contracts and gets smaller and hotter until the core temperature is sufficient to start the nuclear burning of hydrogen. This marks the end of the stellar childhood phase (bottom left). While the young star evolves from its birth to the beginning of hydrogen burning, its pulsation properties change: The least evolved (youngest), stars pulsate slower and the most evolved (oldest) stars pulsate faster. This video relates to a paper that appeared in the July 3, 2014, issue of Science Express, published by AAAS. The paper, by Konstanze Zwintz at KU Leuven in Leuven, Belgium, and colleagues was titled, "Echography of young stars reveals their evolution." view more
Credit: [Credit: Animation: Pieter Degroote (KU Leuven); Background image: ESO]