Unique Stellar Chemistry of Star A980 | 23 Jun 2025

Source: PIB

Why in News?

Scientists at the Indian Institute of Astrophysics (IIA), Bengaluru identified a rare helium-rich star (A980) exhibiting a rare chemical composition, challenging existing models of stellar evolution and nucleosynthesis.

What are the Key Facts Related to Star A980?

• A980 lies in the Ophiuchus constellation, about 25,800 light years from Earth.
  • It shows the first-ever detection of singly-ionized germanium (Ge II) in an EHe star, with germanium levels eight times higher than in the Sun.
  • About Star A980: A980 is a cool Extreme Helium (EHe) star, a rare class of evolved stars made almost entirely of helium with little to no hydrogen, typically formed through the merger of a helium-rich and a carbon-oxygen rich white dwarf.
• Stellar Models and Star A980: Stellar models explain how stars form, evolve, and create elements. They suggest heavy elements like germanium form in supernovae or AGB stars, not in Extreme Helium (EHe) stars.
  • However, Star A980, an EHe star, shows unusually high germanium levels, challenging these models. 
  • It suggests that element formation may happen during white dwarf mergers, a process not well covered in current theories, indicating the need to revise stellar evolution models.

Indian Institute of Astrophysics (IIA)

• IIA is a premier research institution under the Department of Science & Technology (DST), dedicated to astronomy, astrophysics, and related physical and engineering sciences. 
• It traces its origins to the Madras Observatory established in 1786, which was later relocated to Kodaikanal in 1899. It was renamed as IIA in 1971 and shifted its headquarters to Bengaluru in 1975.