Mystery of repeating radio waves solved, scientists trace origin of slow radio pulse – Times of India

For years, astronomers have been puzzled by the slow, repeated bursts of radio waves from space. Now, for the first time, they have tracked one of these signals back to its source: a A red dwarf starpossibly paired with a White DwarfAccording to the journal Conversation, the remains of a star that died long ago.Mysterious signal

In 2022, astronomers discovered unusual radio pulses repeating every 18 minutes. The bright signal lasted for three months before disappearing. These pulses were different from neutron stars, called pulsars, which typically spin rapidly and send out radio waves every second or faster.
The slow pulses did not fit current theories, leading scientists to consider new physics or unknown ways in which pulsars could emit radio waves. Since then, about ten similar signals, known as “long-period radio transients”, have been found, but their sources remain unclear.

Slow radio pulses.

Most of these signals were detected in the crowded center of the Milky Way, making it difficult to identify their exact sources among the thousands of stars.
To solve this, the researchers used Murchison Widefield Array In Western Australia, a telescope that scans large areas of the sky. Curtin University student Csanád Horváth analyzed data from less crowded areas and found a new source: GLEAM-X J0704-37.
The object emits radio pulses that last for a minute, like other transients, but at a slower rate — once every 2.9 hours, the slowest rate ever detected.

A red dwarf star

Follow-up observations with the MeerKAT telescope in South Africa confirmed that the radio waves came from a red dwarf star. These stars are very common, making up 70% of the stars in the Milky Way, but they are too faint to see without a telescope.
The researchers noticed that the pulses arrived a little earlier or later in a repetitive pattern, suggesting that the red dwarf is coupled to an unseen object in orbit. They believe this companion is likely a white dwarf.
Scientists believe that the red dwarf ejects charged particles into the stellar wind, which interact with the white dwarf’s magnetic field to generate radio waves. This is similar to how the solar wind produces auroras and radio waves on Earth.