astronomer using james webb space telescope (JWST) peeked through the fence behind the Milky Way and noticed something strange about the star infants playing next to them.
While zooming in on young star cluster NGC 602 in the nearby Small Magellanic Cloud (SMC), researchers discovered what could be the first evidence of a brown dwarf ever seen outside the Milky Way. I discovered something. brown dwarf, orfailed star” is a unique celestial body that is larger than the largest planets but not heavy enough to sustain nuclear fusion like a star.
The observations include surprising new images of star clusters from JWST’s near-infrared camera, revealing new insights into how these strange failed stars form. The research team announced their findings on October 23rd. astrophysical journal.
“Brown dwarfs appear to form similar to stars, they just don’t capture enough mass to become full stars,” said study lead author peter zeidlersaid researchers from the European Space Agency (ESA) in a paper. statement. “Our results are in good agreement with this theory.”
NGC 602 is an approximately 3 million-year-old star-forming cluster located on the outskirts of the SMC, a satellite galaxy of the Milky Way. 3 billion stars. (By comparison, our galaxy contains an estimated 100 billion to 400 billion stars.) Orbiting about 200,000 light-years from Earth, the SMC is the Milky Way’s closest intergalactic neighbor. It is one of the galaxies and is a frequent subject of astronomical research.
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Previous observations of NGC 602 taken with the Hubble Space Telescope revealed that the cluster contains a population of young, low-mass stars. Now, thanks to JWST’s incredible sensitivity to infrared light, astronomers have fleshed out the newborn forms of these stars and revealed exactly how much mass they accumulated during their short lives.
The results suggest that the masses of the 64 stellar bodies in the cluster range from 50 to 84 times larger. Jupiter. According to the ESA, brown dwarfs typically weigh between 13 and 75 masses of Jupiter, making many of these objects prime candidates for the first brown dwarfs discovered outside our galaxy. are.
These failed stars appear to have formed in much the same way as stars like: solar: Through the collapse of a huge cloud of gas and dust. But for a collapsed cloud to become a star, it must continue to accumulate mass until it reaches an internal temperature and pressure high enough to cause hydrogen fusion in its core. In the process, hydrogen atoms combine with helium, releasing energy as light and heat.
Brown dwarfs never gain enough mass to sustain permanent fusion and remain larger than planets but smaller and dimmer than stars. This ignition failure could be a common outcome in space. Astronomers have discovered about 3,000 brown dwarfs in the Milky Way and estimate they may exist. 100 billion In our galaxy alone, they could be as common as stars themselves.
Further studying this group of failed stars outside our galaxy may help reveal why so many stars seem to fail to ignite. But researchers say these strange objects may also reveal new insights into the early universe. NGC 602 is a young star cluster that contains small amounts of elements heavier than hydrogen and helium, so its composition is similar to that of the ancient universe, before later generations of stars littered the universe with various elements found near Earth. is considered to be very similar. .
“By studying the young, metal-poor brown dwarfs newly discovered in NGC 602, we are getting closer to uncovering the secrets of how stars and planets formed under the harsh conditions in the early universe.” said the study co-author. Elena Sabbiscientists at the National Science Foundation’s NOIRLab, the University of Arizona, and the Space Telescope Science Institute. statement.
