Just two weeks ago, the spacecraft arrived at its target asteroid, Bennu, from which it will collect a sample of pristine material in 2020. The researchers are eagerly awaiting the discoveries that lie ahead for NASAвЂ™s OSIRIS-REx asteroid sample return mission. вЂњWhen Lucy and I started collaborating on this project, we realized that we could reconcile what we found in meteorites and what we observe in space,вЂќ says coauthor Tom Zega, associate professor of cosmochemistry, planetary materials, and astrobiology in the UA Lunar and Planetary Laboratory. The team used radio telescopes at the Arizona Radio Observatory and Institut de Radioastronomie Millimetrique (IRAM) to observe rotational spectra emitted by the molecules in the K4-47 nebula, which reveal clues about their mass distribution and their identity. The discovery was made possible through a collaboration between disciplines that traditionally have remained relatively separate: astronomy and cosmochemistry. The findings have implications for the identification of stardust and the understanding of how common stars create elements such as oxygen, nitrogen, and carbon, the authors say. ItвЂ™s more like a stellar eruption.вЂќ Dust in space вЂњA helium flash doesnвЂ™t rip the star apart like a supernova does. вЂњThis process, during which the material has to be spewed out and cooled quickly, produces 13C, 15N, and 17O,вЂќ explains Ziurys, a professor with dual appointments in the Steward Observatory and the chemistry and biochemistry department at the University of Arizona. In lieu of cataclysmic explosive events forging heavy isotopes, the team suggests they could be produced when an average-size star such as our sun becomes unstable toward the end of its life and undergoes a so-called helium flash, in which super-hot helium from the starвЂ™s core punches through the overlaying hydrogen envelope.

It turns out your average garden variety stars are capable of producing them as well.вЂќ вЂњThe fact that weвЂ™re finding these isotopes in K4-47 tells us that we donвЂ™t need strange exotic stars to explain their origin. вЂњThe models invoking only novae and supernovae could never account for the amounts of 15N and 17O we observe in meteorite samples,вЂќ says Lucy Ziurys, senior author of the paper, which appears in Nature. These isotopes differ from their more common forms by containing an extra neutron inside their nucleus.ДЇusing an additional neutron onto an atomic nucleus requires extreme temperatures in excess of 200 million degrees Fahrenheit, leading scientists to conclude those isotopes could only be formed in novae-violent outbursts of energy in aging binary star systems-and supernovae, in which a star blows itself apart in one cataclysmic explosion. To their surprise, the researchers found that some of the elements that make up the nebula-carbon, nitrogen, and oxygen-are highly enriched with certain variants that match the abundances seen in some meteorite particles but are otherwise rare in our solar system: so-called heavy isotopes of carbon, nitrogen, and oxygen, or 13C, 15N, and 17O, respectively. Classified as a nebula, K4-47 is a stellar remnant, which astronomers believe was created when a star not unlike our sun shed some of its material in a shell of outflowing gas before ending its life as a white dwarf. Researchers used radio telescopes in Arizona and Spain to observe gas clouds in the young planetary nebula K4-47, an enigmatic object approximately 15,000 light-years from Earth. (Credit: ESA/Hubble & NASA/Judy Schmidt) A stellar remnant Having nothing to do with planets, a planetary nebula is a glowing, often colorful, shell of gas and dust shed into space by a dying star at high speed. The object of this study, K4-47, is much less known, but may be similar in appearance. The Butterfly Nebula, also known as the Twin Jet Nebula, is an example of a so-called bipolar planetary nebula. Meteorites commonly contain traces of a type of stardust that, until now, was believed to form only in exceptionally violent, explosive events of stellar death known as novae or supernovae-too rare to account for the abundance preserved in meteorites.

Most everything that makes up Earth, even life itself, consists of elements made by previous stars, including silicon, carbon, nitrogen, and oxygen. When stars die, they seed the cosmos around them with the elements that go on to coalesce into new stars, planets, asteroids, and comets. New research brings scientists closer to solving a long-standing mystery about the origins of stardust.Д®verything around you-your desk, your laptop, your coffee cup-in fact, even you-is made of stardust, the stuff forged in the fiery furnaces of stars that died before our sun was born.

What is stardust