Revolutionary Breakthrough: IUCAA Researchers Use Mira Stars to Unveil the Secrets of the Universe’s Expansion | Pune News
Pune: For those captivated by the stars, a thought often lingers-just how far are they from Earth? A groundbreaking study led by Anupam Bhardwaj at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) has provided new insights, determining the Hubble constant with an impressive accuracy of 3.7% using Mira stars for the first time. This research, published in the Astrophysical Journal, is pivotal as the Hubble constant indicates the current rate of expansion of the universe.
Despite its significance, a puzzling discrepancy-dubbed the Hubble tension-exists in the measurements of this constant across different regions of the universe. “Solving this puzzle is crucial in cosmology, as the Hubble constant is essential for understanding the universe’s size and age,” explained Bhardwaj.
The researchers focused on Mira, a periodic variable star known for its regular fluctuations in brightness. This two-star system consists of a dominant red giant, Mira A, and its faint companion, likely a white dwarf, named Mira B. By measuring their apparent brightness from Earth against their intrinsic brightness, scientists were able to calculate their distance. “We utilized Miras in our galaxy as reference points to determine the most precise cosmic expansion rate based on these stellar bodies,” said Bhardwaj. He emphasized the study’s importance not only for mapping the universe’s age but also for enhancing our comprehension of dark energy, the enigmatic force believed to be driving the universe’s accelerated expansion.
Traditionally, astronomers have measured the Hubble constant through various methods. Bhardwaj’s approach is particularly noteworthy as Miras have not been previously employed for this purpose. “While Cepheid stars typically deliver better precision, Miras offer an independent verification of Cepheid-based Hubble constant values. Their alignment suggests that the Hubble tension isn’t merely a result of measurement inaccuracies,” Bhardwaj noted, reflecting on his transition from researching Cepheid stars to Miras over the past five years.
Nobel laureate Adam Riess, a co-author of the study affiliated with the Space Telescope Science Institute and Johns Hopkins University, remarked that the consistent values derived from both Cepheid and Mira stars hint at potential new physics.
Understanding the Hubble constant with precision across different star types bolsters the argument that the Hubble tension is not the outcome of a singular measurement error. This work opens avenues for using Mira stars in upcoming high-precision measurements, aiding in clarifying or resolving the ongoing Hubble tension debate. Furthermore, it may provide critical insights into the later stages of Mira-like star evolution and their extensive atmospheres, which are rich in gas and dust.
Though the cosmic implications are vast, there remains no consensus on what new physics might illuminate the Hubble tension. The variability of dark energy over time is one of the most intriguing mysteries in modern cosmology, making the pursuit of answers more exciting than ever.
In summary, Bhardwaj’s research represents a significant advancement in our quest to understand the universe, blending rigorous scientific inquiry with the timeless human fascination with the cosmos. As scientists continue to investigate these celestial wonders, the possibilities for discovery remain profound and tantalizing.
Original Source: https://timesofindia.indiatimes.com/city/pune/iucaa-researchers-use-mira-stars-to-measure-rate-of-universes-expansion/articleshow/123621899.cms
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Publish Date: 2025-09-01 01:15:00
