Why do a pair of planets and stars 12 light-years away emit radio signals?

In October of this year, you can see the constellation Cetus in the evening sky, which is visible to the naked eye, high above the horizon. It is also likely to be looking in the general direction of an alien world called YZ Ceti b that has suddenly become a concern for astronomers.

YZ Ceti b is a rocky, Earth-sized exoplanet (a planet orbiting a star other than our sun) orbiting a small red dwarf star, YZ Ceti, 12 light-years from Earth, a handshake’s distance in astronomical terms. Astronomers are excited because they have detected a repeating radio signal from this exoplanet that indicates the presence of a magnetic field – a prerequisite for a habitable planet – around it.

How was it discovered?

The discovery was made by Jackie Feldsen of Bucknell University, Pennsylvania, and Sebastian Pineda of the University of Colorado, Boulder, using the Carl G. Jansky Large Array radio telescope in New Mexico. They published their findings in the journal natural astronomy on April 3.

They had to run multiple rounds of observations before they could detect radio signals from the star YZ Ceti, which appear to match the orbital period of planet YZ Ceti b. From this, they concluded that the signals were the result of the interaction between the planet’s magnetic field and the star.

Dr. Pineda said via email to Hindu.

Why is the magnetic field important?

Just as a burst of energy from the Sun sometimes disrupts Earth’s telecommunications and damages Earth-orbiting satellites, intense bursts of energy from the exchange of stars and exoplanet YZ Ceti produce stunning auroral lights.

“We see this indirectly in the form of the radio emissions that we receive,” said Dr. Pineda.

These radio waves, strong enough to be picked up on Earth, confirmed the existence of an extrasolar magnetic field. Such signals can only be produced if an exoplanet orbits very close to its parent star and has its own magnetic field to influence stellar winds and generate signals.

What is included in the YZ Ceti b?

This is confirmed by the small orbit of YZ Ceti b: astronomers have determined that it takes the planet only two Earth days to circle its star. For comparison, Mercury, which has the smallest planetary orbit in the solar system, takes just under three Earth months to go around the sun.

Since the mid-1990s, astronomers have found hundreds of planets orbiting stars similar to the Sun, indicating that planet formation in the galaxies of the universe is more common than scientists think. Data from space science missions such as the Kepler, Gaia and James Webb telescopes indicate that there are more than 300 billion planets in the Milky Way alone.

With so many exoplanets in the same “neighborhood” of the Sun, nearly half of all stars visible in the sky could house rocky, Earth-size planets in habitable orbits around it. To have a sustainable atmosphere and water, a planet must be a certain distance from its star (in orbits said to be in the star’s “Goldilocks Zone”), or it will burn up.

Earth, for example, would have been more like hot and sultry Venus if it were just a little closer to the sun — or cold and barren like Mars if it were farther away. In fact, astronomers believe that approximately 30% of all discovered planetary-stellar systems could contain such temperate zones.

How common are these magnetic fields?

With such massive numbers, it always made sense that strong planetary magnetic fields would be common outside the solar system. However, although many of the larger exoplanets discovered to date have magnetic fields, planetary scientists have never been able to pinpoint such fields at all. smallestAnd rocky Exoplanets – until now.

Dr Pineda noted that if the latest findings are confirmed by further research, they “will prove the potential of the methodology to lead to the magnetic characterization of exoplanets.”

This is important because the survival of a planet’s atmosphere may depend on the presence or absence of a strong magnetic field, because the field protects its atmosphere from erosion by charged particles blowing from its star. Dr Benady agreed: “Planets close to their stars are usually very hot and their atmospheres have likely been eroded away over the billions of years of the exoplanet system’s history.”

what happened after that?

Oddly enough, Mars orbiting the Sun at a “safe” distance has a similar story to tell: Mars and Earth were pretty much the same billions of years ago, with much water, warm oceans, precipitation, and similar atmospheric systems. But despite this, life began on one planet while the other became dry and cold as the solar winds stripped it of most of its atmosphere. So is this also the story of the YZ Ceti b?

“We hope to get additional feedback on this target,” said Dr. Benadi. “Long-term observation is important to confirm these results and further investigate the properties of radio signals.” One thing is certain, though: These findings will help astronomers learn more about rocky netherworlds in the deepest depths of space that run rings around their parent stars.

Prakash Chandra is a science writer.

• Astronomers are excited because they have detected a repeating radio signal from YZ Ceti b – a rocky, Earth-sized exoplanet that indicates the presence of a magnetic field – a prerequisite for a habitable planet – around it.

• The discovery was made by Jackie Feldsen of Bucknell University, Pennsylvania, and Sebastian Pineda of the University of Colorado, Boulder, using the Carl G. Jansky Large Array radio telescope in New Mexico. They published their findings in the journal natural astronomy on April 3 .

• This is important because the survival of a planet’s atmosphere may depend on the presence or absence of a strong magnetic field, because the field protects its atmosphere from erosion by charged particles blowing from its star.