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Astronomers have recently discovered a new millisecond pulsar using the Murchison Widefield Array (MWA) as part of the ongoing Southern-sky MWA Rapid Two-metre (SMART) survey. The discovery is expected to enhance our understanding of neutron stars and support future radio astronomy missions.

About Murchison Widefield Array (MWA)

The Murchison Widefield Array (MWA) is a low-frequency radio telescope located at the Murchison Radio-astronomy Observatory (MRO) in Western Australia, which also hosts the future Square Kilometre Array-Low (SKA-Low).

It is an international collaboration involving 20 research institutions from Australia, Canada, China, Japan, and the United States, led by Curtin University, Australia.

The telescope consists of 4,096 spider-like antennas that operate in the 70–300 MHz frequency range. It is designed with a very wide field of view, high angular resolution, nanosecond time resolution, and digital pointing capability, enabling it to rapidly scan large portions of the sky and detect faint or short-lived cosmic phenomena.

Major Scientific Applications

The MWA is used to study a wide range of astrophysical phenomena, including:

• The Epoch of Reionization, when the first stars and galaxies formed.
• Structure and evolution of galaxies and galaxy clusters.
• The Sun and space weather, including solar flares and coronal mass ejections.
• Transient radio sources such as pulsars and Fast Radio Bursts (FRBs).
• The interstellar medium and cosmic magnetic fields.

Southern-sky MWA Rapid Two-metre (SMART) Survey

The SMART Survey is an ongoing pulsar search programme using the MWA to identify previously unknown pulsars in the Southern Hemisphere.

It is the only pulsar survey currently operating at low radio frequencies (140–170 MHz) in the Southern Hemisphere. Once completed, the survey is expected to discover hundreds of new pulsars and will provide an important reference database for future observations with the Square Kilometre Array (SKA-Low).

Square Kilometre Array (SKA)

The Square Kilometre Array (SKA) is an international project to build the world's largest and most sensitive radio telescope for exploring the universe.

The telescope is being developed across two continents:

• SKA-Low in Australia
• SKA-Mid in South Africa

Its operational headquarters are located in the United Kingdom, while construction officially commenced on 5 December 2022.

The SKA aims to investigate some of the most fundamental questions in astronomy, including the origin of the Universe, formation and evolution of galaxies, cosmic magnetism, and the search for extraterrestrial life.

India became a member of the SKA project in December 2022.

What are Pulsars?

Pulsars are rapidly rotating neutron stars that emit highly regular beams of electromagnetic radiation, primarily in the radio wavelength.

Neutron stars are extremely dense remnants formed after the gravitational collapse of massive stars during a supernova explosion. Although they possess masses between 1.18 and 1.97 times that of the Sun, they are only about 20 km in diameter, making them among the densest known objects in the Universe.

Pulsars possess extremely strong magnetic fields, which channel charged particles towards the magnetic poles, producing narrow beams of radiation. Since the magnetic axis is usually inclined relative to the rotational axis, these beams sweep across space like a lighthouse. When the beam points toward Earth, it is detected as a pulse of radiation.

The interval between successive pulses—ranging from milliseconds to several seconds—is known as the pulsar period.