Magnetic Clues from Space: First Detection of Circular Polarisation Near a Massive Protostar

 

Magnetic Clues from Space: First Detection of Circular Polarisation Near a Massive Protostar

Context

An international team led by astronomers from the Indian Institute of Space Science and Technology (IIST) has made a groundbreaking discovery: radio emission with circular polarisation near a massive protostar, IRAS 18162-2048, located about 4,500 light years away in the Milky Way galaxy.

The discovery offers the first direct clue to the strength of magnetic fields near such a young, massive protostar, crucial for understanding how massive stars form and evolve.

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🔭 What is a Protostar?

• A protostar is the earliest phase of star formation.

• It forms when a dense region within a molecular cloud begins to collapse under gravity, accumulating gas and dust.

• Massive protostars eventually become stars that are more than 8–10 times the mass of the Sun.

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📡 Key Scientific Breakthrough

Element	Description
Circular Polarisation	Occurs when the electric and magnetic field vectors of radio waves rotate in a circular pattern as they propagate.
IRAS 18162-2048	A massive protostar known for powering HH80-81, one of the largest and brightest bipolar jets in the Milky Way.
Discovery Tool	Observations made using the Karl G. Jansky Very Large Array (VLA) in the U.S.
Publication	The Astrophysical Journal Letters (July 2025). Title: First Detection of Circular Polarization in Radio Continuum Toward a Massive Protostar.

🧲 Significance of the Discovery

1. First-ever detection of circularly polarised radio waves from a massive protostar.

2. Helps measure magnetic field strength, previously only inferred in low-mass protostars.

3. Indicates the magnetic field near the protostar is ~100 times stronger than Earth’s.

4. Supports the theory that magnetic fields drive bipolar jets, similar to black holes and active galactic nuclei (AGN).

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📌 GS Paper III Relevance – Science & Technology

✅ Astrophysics Advancements

• Discovery contributes to understanding star formation, magnetohydrodynamics, and interstellar physics.

• Validates existing theoretical models of magnetic field-driven jet ejection.

✅ Space Research in India

• Demonstrates India's leadership in fundamental space science.

• Enhances India’s global reputation in radio astronomy and astrophysics.

✅ Research Infrastructure

• Utilization of global collaboration (VLA in the U.S.) reflects the importance of international scientific cooperation.

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⚖️ Ethical, Strategic, and Developmental Aspects

Dimension	Implication
Strategic	Strengthens India’s profile in advanced scientific domains like astronomy and space science.
Educational	Encourages youth to pursue research in astrophysics and related disciplines.
Technological	Pushes development in radio wave instrumentation, data analysis, and space simulation.

🔍 Prelims Pointers

Fact	Details
Protostar	Earliest stage in star formation.
Circular Polarisation	Rotation of electromagnetic wave fields in a spiral motion.
IRAS 18162-2048	Protostar powering HH80-81 jet, ~4,500 light years away.
HH80-81 Jet	A large, high-velocity bipolar jet associated with IRAS 18162-2048.
VLA (USA)	Karl G. Jansky Very Large Array, used for radio astronomy.
Magnetic field strength near protostar	~100x stronger than Earth’s magnetic field.

📝 Mains Practice Questions

1. “Understanding the role of magnetic fields in star formation is key to solving larger cosmic mysteries.” Examine in the context of recent observations from IRAS 18162-2048.

2. Discuss the significance of circular polarisation in astrophysics and its implications for star and jet formation theories.

3. How can India leverage global collaborations in astronomy to enhance its space science capabilities?

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🧭 Way Forward

1. Boost Radio Astronomy in India

   • Strengthen indigenous facilities like the Giant Metrewave Radio Telescope (GMRT).

   • Foster new projects under ISRO and IIST collaboration.

2. Promote Global Collaboration

   • Encourage partnerships with top institutions like NRAO, ESO, NASA, and ESA.

3. Support Young Researchers

   • Increase research grants and fellowships for space sciences.

   • Build academic capacity in astrophysics and fundamental physics.

4. Public Science Literacy

   • Translate such breakthroughs into accessible formats for school and college students.

   • Highlight India's scientific achievements in media.

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Conclusion

The detection of circular polarisation near a massive protostar marks a historic step in space research, reinforcing how India’s scientific community is pushing frontiers in understanding the universe. As magnetic mysteries begin to unravel, they promise to reshape our understanding of star formation, galactic evolution, and the forces that govern the cosmos.