They have enormous proportions – and their importance is also huge: In the May issue, bild der wissenschaft reports on the latest insights into the secrets of the largest stars in the universe. New observations therefore shed light on the formation and development of the giant stars up to their explosive end. It also elucidates their role as gigantic stardust factories and their importance in the early days of the cosmos.
A look at the night sky makes it clear again and again: Our sun is just one star among countless others. The size of our home star is only average: There are stars in the universe and in our Milky Way that put them far in the shade. Some of the radiant giants have a diameter that would even exceed the orbit of Saturn in our solar system. These giant stars are believed to be of great importance in the evolution of galaxies. However, they still pose some puzzles to astronomers.
In the first article of the three-part title story, bdw author Thomas Bührke reports on the latest findings on the most massive known stars in our region of the universe. They shine in the Tarantula Nebula in the Large Magellanic Cloud, about 160,000 light-years from Earth. Astronomers have now succeeded in depicting these giants, which can weigh up to 200 solar masses, in more detail than ever before. This allowed conclusions to be drawn about their development. As Bührke reports, the giants end up in a supernova explosion within a few million years. As is becoming apparent, a powerful particle wind plays a decisive role in this rapid development. Bührke reports in the article “Superstars in the Tarantula Nebula” that it causes the stellar buzzers to lose more than 100 solar masses before they explode.
Of dust factories and primeval times
The bdw author Thorsten Dambeck then focuses on an extremely productive duo of two giant stars in the Swan constellation. The keen view of the WR 140 binary and its dusty surroundings is thanks to the James Webb Space Telescope, which has been delivering data since 2022. It becomes clear that the doomed partner of the system shows enormous activity in its last phase of life: In connection with its partner, it hurls large amounts of matter into space. Dust production reaches a maximum every 7.93 years. This is probably due to intense stellar winds: the hot surfaces of massive stars appear to emit intensely ionized gas. It can then clump together into dust particles containing organic molecules, according to the article The Stardust Factory.
The cover story is rounded off by a look at the role of the giant stars in the early days of the cosmos: The bdw astronomy expert Rüdiger Vaas reports how astronomers use the James Webb telescope as a kind of time machine to study the early giant stars of the universe track to come. As he explains, special giant stars could have decisively shaped the evolution of the universe: short-lived giants composed almost entirely of hydrogen and helium. Vaas reports how astronomers try to get clues about these mysterious celestial bodies of the past. Perhaps they have already found what they are looking for, according to the article “Primeval Times of the Universe”.
You can read the articles on the cover topic “Monsterstars” online as part of a bdw+ subscription, or you can find them in the May issue of bild der wissenschaft, which will be available in stores from April 18th.