Exploring deep space is navigation A frustrating minefield of scientific puzzles. What happens inside a black hole? We don't know. Where is the dark energy that makes up 68% of the universe? I couldn't tell. Why is there more matter than antimatter in general? Honestly, no idea. So a good day for one of the many, many mysteries of the universe to be clarified. And that brings us to planetary nebulae and their confusing “sulfur anomaly.”
The term “planetary nebulae” is actually a misnomer because these clouds of gas and dust have nothing to do with planets (William Herschel named them as such in 1785. Because of its circular shape, like a planet). In fact, these nebulae are the discarded layers of a dying star as it becomes a white dwarf. Although they live longer than humans, NPs last only a few tens of thousands of years, a blink of an eye compared to the billions of years that the stars that make them live.
Although scientists know very well what NPs are, their composition is a mystery, especially since these clouds must contain more sulfur than they do. Sulfur is an “α element” and must be produced like other elements such as oxygen, neon, argon, and chlorine. But previous studies of low- to intermediate-mass stars producing NPs have shown low amounts of sulfur. So… what happens?
Two scientists from the University of Hong Kong They set out to finally answer this stinking riddle. In a new article published in Astrophysical Journal Letters Earlier this month, Shuyu Tan and Quentin Parker described how they used the “exceptionally high signal-to-noise (S/N) optical spectrum” of about 130 NPs at the center of the Milky Way, observed by the Very Large Telescope. From Chile.
Due to the low background noise, the features of the spectra were particularly detailed. However, the team made an important decision that finally solved the mystery: they used argon instead of oxygen as a base metal comparator, which turned out to be more relevant when searching for the missing sulfur.
Clear data and results of argon exchange eliminated the “sulfur anomaly”; In other words, there was not an anomaly in the first place. This finding refutes previous theories that attempted to explain the lack of sulfur in NPs.
“We show for the first time in NPs α-element sulfur in a keyhole passage with both oxygen and argon,” the paper states. “We reject hypotheses that the anomaly originates from an underestimation of the upper levels of sulfur ionization.”
It may not be the answer to one of the universe's greatest mysteries, but when it comes to understanding deep space, it's always nice to know a little more than you did before.
Darren lives in Portland, has a cat, and writes/edits about science fiction and how our world works. If you look hard enough you can find his previous stuff on Gizmodo and Paste.