Observatories are constantly receiving radio signals from deep within the Universe. Most often their sources are neutron stars, which is why they are called pulsars. However, according to astronomers, these have nothing to do with the recently discovered GLEAM-X J0704-37 source.

The “echo” of various events in space reaches the Earth, it is especially interesting to “listen” to radio signals repeating themselves in a very timely manner. When astronomers began to notice this in the 1960s, it became almost a sensation: They suspected a message had been received from an extraterrestrial civilization. This is how neutron stars or pulsars (the cores of “dead” massive stars) were discovered.

When a heavy star of the Betelgeuse type (15 times more massive than the Sun) “burns up”, it sheds its entire outer shell (explodes as a supernova) and its core contracts to a diameter of tens of kilometers, begins to rotate. It rotates around its axis at tremendous speed and emits strong radiation from both poles. At the same time, the axis of rotation fluctuates very much, so the poles of this cosmic “yule” are sometimes revealed to us, then hidden, creating a “pulse”.

Neutron stars typically rotate around their axes at hundreds of revolutions per second, so the “pulse” from them comes with a corresponding frequency. However, much slower repeating radio signals come from space. I recently mentioned one of these cases. Astrophysics Journal Letters An international team of astronomers led by researchers from Curtin University (Australia). This GLEAM-X resource is J0704-37.

Each of its signals lasts approximately 30 to 60 seconds in a row and repeats after an average of 2.9 hours. Scientists have determined its location: according to them, the source is 4,900 light years away from us, in the “sparsely populated” part of the Galaxy. Thanks to this, it was possible to think about it. Looking at its light spectrum, astronomers see that it is a red dwarf: a star smaller and “lighter” than the Sun that can “burn” for billions, if not trillions, of years.

Red dwarfs are, of course, famous for their flares, which seem completely harmless compared to those on the sun, but these flares are erratic. Astronomers emphasized that such a star alone could not emit such radio signals. That’s why they suspect he has a companion.

As scientists explain, this companion cannot be a “living” star, that is, a thermonuclear fuel burning inside itself (this is called the main sequence in astronomy): it is visible in visible light. Since it is not visible in optics, it remains to conclude that it must be the core of a “dead” star without a shell.

Of course, the first thing that came to my mind was that it was a pulsar, and perhaps its special kind with a super-strong magnetic field was a magnetar. But astronomers are highly doubtful that it is him. They noted that due to the observed spin slowdown, the neutron star must be very old, meaning it could no longer produce such a “radio broadcast”.