The James Webb Space Telescope continues to capture spectacular photos of the universe and the latest is an unusually dense cluster of massive stars that contain more than 10,000 times the mass of the Sun, yet are packed into an unbelievably small volume.
This cluster is called Westerlund 1 and it is about 12,000 light-years away from Earth in the Ara constellation where, the European Space Agency (ESA) explains, it sits behind a huge interstellar cloud of gas and dust. Originally discovered in 1961 by Swedish astronomer Bengt Westerlund, it remains the best-known area to study “extreme stellar physics” and better understand how massive stars exist.
“The unique draw of Westerlund 1 is its large, dense, and diverse population of massive stars, which has no counterpart in other known Milky Way galaxy clusters in terms of the number of stars and the richness of spectral types and evolutionary phases. All stars identified in this cluster are evolved and very massive, spanning the full range of stellar classifications including Wolf-Rayet stars, OB supergiants, yellow hypergiants (nearly as bright as a million Suns), and luminous blue variables,” the ESA explains.
“Because such stars have a rather short life, Westerlund 1 is very young, astronomically speaking. Astronomers estimate the cluster’s age to be somewhere between 3.5 and 5 million years (its exact age is still a matter of debate), making it a newborn cluster in our galaxy. In the future, it is believed that it will likely evolve from an open cluster into a globular cluster. These are roughly spherical, tightly packed collections of old stars bound together by gravity.”
The Milky Way used to produce a lot of stars but has slowed down from its peak around 10 billion years ago and has been in gradual decline ever since. Therefore, Westerlund 1 remains an anomaly in the galaxy and serves as an example of what the Milky Way may have looked like a very long time ago. This cluster, or rather a super-cluster, of stars was probably more common back then, astronomers theorize.
“These are young clusters of stars that contain more than 10,000 times the mass of the Sun, packed into an unbelievably small volume. They represent the most extreme environments in which stars and planets can form. Only a few super star clusters still exist in our galaxy — of which Westerlund 1 is one — but they offer important clues about this earlier era when most of our galaxy’s stars formed.”
Because they’re so tightly packed as well as large, Webb’s photo of them appears to brightly sparkle with extreme intensity. It’s an undeniably gorgeous photo that, like all of Webb’s observations, is packed with scientific data, too.
“This super star cluster now provides astronomers with a unique perspective towards one of the most extreme environments in the Universe. Westerlund 1 will certainly provide new opportunities in the long-standing quest for more and finer details about how stars, and especially massive stars, form,” the ESA concludes.
Image credits: ESA/Webb, NASA & CSA, M. Zamani (ESA/Webb), M. G. Guarcello (INAF-OAPA) and the EWOCS team
Source link
