What is YZ Ceti b?

About YZ Ceti b:

• It is a rocky earth-sized exoplanet rotating around a small red dwarf star.
• It is barely 12 light-years from Earth.
• The astronomers determined that the planet takes just a couple of Earth days to circle its star.

Why does the magnetic field matter?

• The survival of a planet’s atmosphere may well depend on its strong magnetic field.
• The magnetic field protects the planet’s atmosphere from being eroded by the charged particles blowing in from its star.

Key Facts about the Exoplanets 

• These are also called extrasolar planets.
• These are a planetary body which is outside the solar system and that usually orbit a star other than the Sun. 
• Exoplanets come in a wide variety of sizes, from gas giants larger than Jupiter to small, rocky planets about as big around as Earth or Mars.
• These are made up of elements similar to those of the planets in our solar system, but their mixes of those elements may differ.
• Most exoplanets are found through indirect methods: measuring the dimming of a star that happens to have a planet pass in front of it, called the transit method

Q1) What is Red dwarf star?

A red dwarf star is a type of low-mass star that is the most common type of star in the Milky Way galaxy. These stars are smaller and cooler than the Sun, with surface temperatures that range from about 2,200 to 3,500 Kelvin. They are also much dimmer than the Sun and emit most of their light in the infrared part of the spectrum.

Source: Why is a star-planet pair just 12 light-years away emitting radio signals?