Shakti and Shiva: The ancient star duo in the galactic creation story

Scientists recently discovered two ancient star streams in the Milky Way, known as Shakti and Shiva, revealing the earliest stages of the formation of the Milky Way. These stellar structures were identified using data from the Gaia space telescope and are believed to have merged with the Milky Way about 12 billion years ago, providing important clues to its early evolution.

Shakti and Shiva, named after Hindu gods, are composed of stars with similar chemical compositions, suggesting they formed about 12-13 billion years ago. Each structure is approximately 10 million times more massive than the Sun, underscoring their importance during the formation of the Milky Way.

The discovery marks an important milestone in understanding the galaxy’s tumultuous infancy.

Khyati Malhan, principal investigator at the Max Planck Institute for Astronomy, emphasized the importance of this research for solving fundamental questions about galaxy formation. The Milky Way is a massive spiral galaxy with billions of stars, and its origins can be traced back to these primitive stellar structures.

Launched in 2013, Gaia played a key role in identifying Shakti and Shiva using its precise mapping capabilities to detect their presence. Located within 30,000 light-years from the center of the Milky Way, these star streams provide valuable insights into the early stages of the Milky Way.

The research builds on previous discoveries, including the identification of the Milky Way’s “poor old heart,” another ancient population of stars within the Milky Way’s core. The unique composition of Shiva and Shakti stars, characterized by low metallicity, sets them apart from other stars in the Milky Way.

As researchers delve deeper into the history of the Milky Way, future Gaia surveys are expected to reveal how the Milky Way has evolved since its birth more than 13 billion years ago. Malhan emphasized the need for comprehensive studies to paint a clearer picture of the formation and evolution of galaxies across their vast cosmic timelines.