The James Webb Space Telescope (JWST) has observed a bizarre set of rings around an unusual star system, which may be evidence for carbon that formed planets like Earth across the cosmos.
The system, called WR 140, is located about 5600 light years from Earth and contains two stars. One is a Wolf-Rayet star â a massive star eight times our sunâs mass â at the end of its life, shedding material into space. Its companion is a supergiant star some 20 times more massive than our sun. Previous observations of the system had shown two rings of carbon-rich dust emitting from the stars, puffing out as they approach each other in their eight-year orbit.
Images taken by JWST in July, however, reveal much more detail. The telescope spied more than 17 rings of dust extending from the stars âalmost like tree ringsâ, says at the National Science Foundationâs NOIRLab in Arizona who led the observations. The rings are not perfectly circular because of the angle from which we are observing the system and the orbits of the stars, making them seem almost artificial â but they are very much real.
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âWeâre essentially tracing out 130 years of this eight-year cycle of dust formation,â says Lau. âIt blew us away. We didnât expect to see that many rings.â
Star systems like this with concentric rings of dust are not too uncommon, says Lau. âThere are maybe 15 that are known,â he says. However, none has been seen in as much detail as this. âThereâs nothing really like WR 140 where you see those series of shells further out,â says Lau. âThatâs where the power of JWST comes in.â
In total, the rings extend more than 10 trillion kilometres from the stars, or about 70,000 times the distance between Earth and the sun. âItâs the furthest distance weâve seen Wolf-Rayet dust survive,â says Lau. That could have major implications for the formation of stars and planets like our own in the cosmos. âWolf-Rayet stars could be an importance source of the carbon that formed our sun or Earth,â says Lau.
Nature Astronomy
Nature
