TWIN STARS (Syllabus GS Paper 1 – Geography)

Context: The Planetary system that includes Earth and its sibling planets orbiting the sun has been remarkably stable during its roughly 4.5 billion years of existence. But not all planetary systems are so lucky, as per a new study involving "twin" stars.

Twin Stars

• About: It refer to pairs of stars that form within the same interstellar cloud of gas and dust, known as co-natal stars. These stars share similar chemical composition, mass, and age, resembling "twins" in the cosmic sense.
• Characteristics: These twin stars, while moving together in the same direction within the Milky Way galaxy, are not binary systems gravitationally bound to each other.
• Effect of Planetary Ingestion: The chemical composition of a star can change if it engulfs a planet, incorporating elements from the consumed world. Higher amounts of certain elements like iron, nickel, or titanium in one of the twin stars indicate remnants of a rocky planet.
• Observations and Findings: In seven out of the studied pairs of twin stars, one of the stars showed evidence of planetary ingestion, suggesting the prevalence of this phenomenon among co-natal stars.

How do twin stars eat planets?

• Possible Causes of Death Plunge: A planet's death plunge into its host star may be triggered by orbital disturbances, such as interactions with larger planets or close encounters with other stars.
• Planetary System Stability: Contrary to popular belief, the stability of planetary systems like our solar system is not guaranteed, as stated by astrophysicist Yuan-Sen Ting.
• Common Instability in Systems: Instability in planetary systems might be more prevalent than previously thought, with approximately 8% of stellar pairs showing evidence of one star consuming a planet.