India’s largest radio telescope plays vital role in detecting universe’s vibrations

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Last Updated01/07/2023

An international team of astronomers from India, Japan and Europe has published the results from monitoring pulsars, called ‘nature’s best clocks’
India’s Giant Metrewave Radio Telescope (GMRT) was among the world’s six large telescopes that played a vital role in providing evidence confirming the presence of gravitational waves using pulsar observations

Pulsars are a type of rapidly rotating neutron stars that are essentially embers of dead stars which are present in our galaxy.
It is like a cosmic lighthouse as it emits radio beams that flashes by the Earth regularly akin to a harbour lighthouse.
As these signals are accurately timed, they are used to unravel the mysteries of the Universe.
In order to detect gravitational wave signals, scientists explore several ultra-stable pulsar clocks randomly distributed across our Milky Way galaxy and create an ‘imaginary’ galactic-scale gravitational wave detector.

These are invisible ripples in space that form when
- A star explodes in a supernova.
- Two big stars orbit each other.
- Two black holes merge.
- Neutron star-Black hole (NS-BH) merges.
They stretch and compress everything in their path, though very slightly, which can only be detected by specialized devices like LIGO.
These were proposed by Albert Einstein in his General Theory of Relativity, over a century ago.
- However, the first gravitational wave was actually detected by LIGO only in 2015.
They travel at the speed of light

GMRT, an indigenous project, is an array of thirty fully steerable parabolic radio telescopes of 45 meter diameter.
It is operated by the National Center for Radio Astrophysics of the Tata Institute of Fundamental Research (NCRA-TIFR).
It functions at the meter wavelength part of the radio spectrum because man-made radio interference is considerably lower in this part of the spectrum in India
Its design is based on the 'SMART' concept - Stretch Mesh Attached to Rope Trusses.
The location for GMRT, Pune meets several important criteria such as
- Low man-made radio noise
- Availability of good communication
- Vicinity of industrial, educational and other infrastructure
- A geographical latitude sufficiently north of the geomagnetic equator in order to have a reasonably quiet ionosphere and yet be able to observe a good part of the southern sky as well.