YZ CETI B

1. Context

2. How was the Discovery Made?

• The discovery was made by Jackie Villadsen from Bucknell University, Pennsylvania, and Sebastian Pineda from the University of Colorado, Boulder, using the Karl G. Jansky Very Large Array radio telescope in New Mexico.
• They had to make multiple observations before they could detect the radio signals from the star YZ Ceti, which seemed to match the orbital period of the planet YZ Ceti b.
• From this, they deduced that the signals were a result of the interaction between the planet's magnetic field and the star.

Image source: NASA

3. Why magnetic field is important?

• Just as energy surges from the sun sometimes disrupt telecommunications on Earth and damage orbiting satellites, intense bursts of energy from the YZ Ceti star exoplanet exchange produce spectacular auroral lights.
• These radio waves, strong enough to be picked up on Earth, confirmed the existence of an exoplanetary magnetic field.
• Such signals can only be produced if the exoplanet orbits very close to its parent star and has its magnetic field to influence the stellar wind and generate the signals.

4. What does this mean for YZ Ceti b?

• YZ Ceti b has a small orbit astronomers determined that the planet takes just a couple of Earth days to circle its star.
• Since the mid-1990s, astronomers have found hundreds of planets orbiting stars similar to the sun.
• To have an atmosphere and sustain water, a planet has to be at a certain distance from its star (in orbits said to be in the star's "Goldilocks Zone") or it will get burnt.
• Earth, for example, would have been a lot more like Venus if it had been just a little closer to the sun or cold like Mars if it had been any farther.
• Astronomers believe nearly 30% of all star systems discovered could potentially have "Goldilocks zones".

5. What are Exoplanets?

• Exoplanets are planets that orbit other stars and are beyond our solar system. The first confirmation of the detection of exoplanets occurred in 1992.
• According to NASA, more than 5,000 exoplanets have been discovered.
• Scientists believe there are more planets than stars as each star has at least one planet orbiting it.
• Exoplanets come in a host of different sizes. They can be gas giants bigger than Jupiter or as small and rocky as Earth. They are also known to have different temperatures, from boiling hot to freezing cold.

Image Source: NASA

6. Discovery of Exoplanets

• Exoplanets are very hard to see directly with telescopes. They are hidden by the bright glare of the stars they orbit.
• So, astronomers use other ways to detect and study exoplanets such as looking at the effects these planets have on the stars they orbit.
• Scientists rely on indirect methods, such as the transit method, which is measuring the dimming of a star that happens to have a planet pass in front of it.
• Other detection methods include gravitational microlensing. Light from a distant star is bent and focused by gravity as a planet passes between the Star and Earth. The same method could hypothetically use our sun to see exoplanets.