The James Webb Space Telescope (JWST) has found the first evidence that millions of supermassive stars, 10,000 times the mass of the Sun, may be lurking at the dawn of the universe.
Born just 440 million years after big Bang, the stars may shed light on how our universe was first seeded with heavy elements. The researchers, who called the giant stars “heavenly monsters”, published their findings May 5 in the journal. Astronomy and astrophysics.
“Today, thanks to the data collected James Webb Space Telescopewe believe we have found the first key to understanding the presence of these unusual stars,” lead author of the study. Corinne Charbonnelprofessor of astronomy at the University of Geneva in Switzerland, said in a statement.
Connected: A new study suggests that the early universe was filled with stars 10,000 times the size of our sun.
Researchers have found the chemical signatures of giant stars inside globular clusters — clusters of tens of thousands to millions of densely packed stars, many of which are among the most ancient to ever form in our universe. About 180 globular clusters dot our Milky Way galaxies and, because they are very old, serve as a window into time for astronomers in the earliest years of our universe.
Mysteriously, some of the stars in these clusters have vastly different proportions of elements (oxygen, nitrogen, sodium, and aluminum) despite having formed around the same time and from the same gas and dust clouds 13.4 billion years ago.
Astronomers believe that this diversity of elements can be explained by the existence of supermassive stars – cosmic giants born in the denser conditions of the early universe that burned their fuel at much higher temperatures, producing heavier elements that subsequently “contaminated” smaller young stars (which usually composed of lighter elements).
But finding these stars was not easy. Somewhere between 5,000 and 10,000 times the size of our Sun, the fire giants burned at temperatures of 135 million degrees Fahrenheit (75 million degrees Celsius). As the larger, brighter, hotter stars die out faster than anyone else, these space monsters have long since met their doom in extremely violent explosions called hypernovae.
“Globular clusters are 10 to 13 billion years old, while superstars have a maximum lifespan of two million years. Therefore, they disappeared very early from currently observed clusters. Only indirect traces remain,” co-author. Mark Gilesthe professor of astrophysics at the University of Barcelona said in a statement.
To detect the scattered chemical remnants of ancient monsters, the researchers aimed the JWST infrared camera at the GN-z11 galaxy, which is one of the most distant and ancient galaxies ever discovered and is located at a distance of 13.3 billion light-years from Earth. Different chemicals absorb and emit light at different frequencies, so by analyzing the light coming from the various globular clusters found in GN-z11, astronomers have found that its stars are not only densely packed, but also surrounded by high levels of nitrogen.
“The strong presence of nitrogen can only be explained by the combustion of hydrogen at extremely high temperatures, which can only be reached by the cores of supermassive stars,” Charbonnel said.
Having found the first clues for celestial monsters, the researchers will study more globular clusters in more galaxies to see if their findings hold true elsewhere.