The Whispers from 28,000 Light-Years Away: Decoding a Black Hole's Secrets | Opinion

Indian scientists using AstroSat have uncovered fascinating behavior in black hole GRS 1915+105. This discovery helps decode how black holes work, boosts India’s space research reputation and contributes to technological advancements on Earth.

Black holes are some of the most mysterious and powerful objects in the universe. We can't see them directly because they pull in everything around them—even light—so they appear completely black and invisible.

They are formed when very big stars come to the end of their life. These stars shine for millions of years by burning hydrogen gas in their core, just like a fire needs fuel to keep burning. But after a long time, the star uses up all of its hydrogen. When there is no more fuel left to keep the fire going inside the star, it loses the energy that was holding it up. As a result, the star collapses under its own heavy weight—and this collapse creates a black hole.

Even though we can't see black holes, scientists can still find them when they are close to another star. In such cases, the black hole pulls gas and other material from its partner star. This gas spins around the black hole and becomes extremely hot—hotter than 10 million degrees, which is much hotter than the surface of the Sun (about 6,000 degrees).

This super-hot gas gives off strong X-rays, which space telescopes can detect. These X-rays help scientists study and understand black holes, even though the black holes themselves are invisible.

Far away in our galaxy—about 28,000 light-years from Earth—lies a strange and fascinating black hole known as GRS 1915+105.

This black hole is part of a unique system where it is paired with a nearby star. It spins very fast and is about 12 times heavier than our Sun.

What makes this black hole so interesting is its unusual and active behavior. Scientists have been closely observing it because it doesn’t act like most other black holes. Studying GRS 1915+105 helps researchers learn more about how these mysterious space objects behave.

Now, what does 28,000 light-years actually mean?

A light-year is a way to measure distance in space. It’s the distance that light travels in one year. Since light is extremely fast—about 300,000 kilometers per second (or 186,000 miles per second)—it can cover a huge distance in a year: around 9.5 trillion kilometers (or 6 trillion miles).

So, when we say this black hole is 28,000 light-years away, it means:

• Light from it takes 28,000 years to reach Earth,
• So we are actually seeing it as it was 28,000 years ago,
• And it is around 266,000 trillion kilometers away from us.

In short, GRS 1915+105 is not just far—it’s incredibly far! Yet, its unique behavior brings it closer to our understanding of the universe.

India’s first space telescope, called AstroSat, was launched in September 2015. Since then, it has been carefully watching the mysterious black hole GRS 1915+105.

AstroSat studies this black hole using different types of light (called multi-wavelength), which helps scientists see things that normal telescopes cannot.

Thanks to AstroSat, we are learning a lot more about how this black hole behaves and changes over time. Its observations give scientists very useful information about one of the most puzzling objects in space.

The black hole GRS 1915+105 shows a special pattern in its X-ray light. It keeps switching between two phases:

• A low-brightness phase called a "dip",
• And a high-brightness phase called a "non-dip".

Each of these phases lasts for a few hundred seconds.

During the bright (non-dip) phase, scientists found something amazing:

The X-ray light was flickering very quickly—about 70 times every second. These regular flickers are called Quasi-periodic Oscillations (QPOs).

But what's really interesting is that these fast flickers disappear completely during the dim (dip) phase. This unique behavior helps scientists better understand what’s happening around the black hole.

These discoveries are helping scientists learn more about what goes on near a black hole, where gravity is extremely powerful and conditions are very harsh.

In fact, GRS 1915+105 works like a cosmic laboratory, allowing scientists to study how black holes behave. Thanks to AstroSat, India’s space telescope, Indian scientists are now able to understand the tiny signals or 'whispers' coming from this black hole, revealing its secrets little by little.

This important research has been published in a well-known international science journal called the Monthly Notices of the Royal Astronomical Society.

The study was done by a team of scientists, including:

• Anuj Nandi from ISRO
• Santabrata Das and Seshadri Majumder from IIT Guwahati
• Sreehari H. from Haifa University

Their work is gaining international attention and shows how Indian scientists are helping us understand the mysteries of space.

– Reports ISRO

Why Studying Black Holes Matters to Us All

How research on distant black holes like GRS 1915+105 benefits common people on Earth

Black holes may seem like mysterious objects far away in space with no connection to our daily lives. But the truth is, studying them brings many benefits—even for common people who may never look through a telescope. Here’s how:

Understanding the Universe Better

Research on black holes helps us learn how the universe works. It explains what happens when big stars die, how black holes form, and how matter behaves under extreme gravity. This satisfies our natural curiosity and helps us understand our place in the cosmos.

Improvement in Technology

To study black holes, scientists create highly advanced instruments—like space telescopes, sensors, and data analysis tools. Over time, this technology often benefits everyday life. For example:

• GPS systems
• Weather forecasting tools
• Medical imaging machines like MRI
• Better phone and camera sensors

These are just a few ways space research reaches into our homes and hospitals.

Pride in Indian Science

Thanks to missions like AstroSat, Indian scientists are now making important contributions to global space research. Discoveries about black holes show that India is a rising space power.

This brings national pride and encourages young minds to dream big and pursue careers in science and technology.

Boost to Education and Awareness

Findings from space missions are used in textbooks, classrooms, and science outreach programs. Learning about black holes makes science exciting and helps students understand complex topics in a fun and engaging way.

Helping Future Space Missions

Studying black holes improves our knowledge of space physics. This is important for planning long-term missions—like sending astronauts deeper into space or building space stations and habitats in the future.

In Conclusion

Even though black holes like GRS 1915+105 are thousands of light-years away, the science behind them has a real impact here on Earth. From better gadgets to a stronger education system, and from national pride to inspiring the next generation—black hole research lights the way for a smarter future.

(Girish Linganna is an award-winning science communicator and a Defence, Aerospace & Geopolitical Analyst. He is the Managing Director of ADD Engineering Components India Pvt. Ltd., a subsidiary of ADD Engineering GmbH, Germany. Contact: girishlinganna@gmail.com)

The opinions expressed are solely those of the author and do not reflect the views or stance of the organization. The organization assumes no responsibility for the content shared.