Indian astronomers discover rare helium-rich star challenges theories of stellar element formation

Astronomers from the Indian Institute of Astrophysics, Bengaluru, have identified an exceptionally rare helium-rich star, designated A980, containing germanium levels eight times greater than those observed in the Sun. The discovery could reshape current understanding of heavy element formation and stellar evolution, as reported by News9, a partner of TV BRICS.

Located approximately 25,800 light years from Earth in the constellation Ophiuchus, A980 was initially classified as a hydrogen-deficient carbon star. However, high-resolution spectral data revealed a composition more consistent with a cool extreme helium (EHe) star, a highly unusual stellar class with very few known examples in the universe.

What sets A980 apart is the unprecedented detection of singly ionised germanium (Ge II) in its atmosphere – the first such observation in an EHe star. Germanium, along with elevated levels of strontium and barium, indicates that the star likely formed through a merger between a carbon-oxygen white dwarf and a helium white dwarf.

This extreme event would have triggered the slow neutron-capture process (s-process), responsible for the synthesis of heavier elements in evolved stars.

The identification of germanium in such abundance challenges longstanding assumptions about where and how elements beyond iron are produced in the cosmos. According to the source, the discovery underscores the critical role of high-resolution spectroscopy in uncovering the hidden chemical complexity of the universe.

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