May 1 (UPI) -- Apparently, pollution isn't strictly an Earth problem. Astronomers in Russia have discovered a star system boasting an atmosphere polluted by heavy elements, including calcium.
The binary solar-type star system was formed from the leftover stellar material scattered throughout RCW 86, a supernova remnant. Researchers at Lomonosov Moscow State University identified high levels of calcium in the stellar system's atmosphere.
Supernova remnants are often associated with neutron stars. When the life of a massive star comes to an end, its outer layers are exploded outward. The star's leftover condensed core forms a neutron star.
But when researchers went looking for a neutron star in RCW 86, they got a bit confused. What they thought was a neutron star, turned out to be quite bright. Neutron stars emit very little optical light.
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Further analysis revealed the presence of a solar type star, or G star. But their observations also measured intense X-ray emissions, an anomaly for a G star.
"The X-ray luminosity of the G star should be significantly less than that was measured," lead researcher Vasilii Gvaramadze said in a news release. "We have come to a conclusion that we deal with a binary system, composed of a neutron star... and a G star."
When the scientists looked back at images of the G star collected in 2015, they found a star system with an increasingly eccentric orbit -- a potentially unstable system. The system finally erupted on the edge of its wind bubble, the bubble of local gas blow outward by the massive star.
Until now, most astronomers believe calcium-rich atmospheres were the results of a helium shell detonation on low-mass white dwarfs. The latest research -- detailed in the journal Nature Astronomy -- offers an alternative explanation.
A calcium-rich stellar atmosphere, researchers say, could be created by the explosion a massive star in a binary system. The team of astronomers plan to continue studying RCW 86 and its unique G star.
"The obtained information could be crucially important for understanding the nature of the calcium-rich supernovae," Gvaramadze said.
