James Webb telescope discovers its first Earth-sized exoplanet

Subject: Sci & Tech

Section: Space

Context:

The National Aeronautics and Space Administration (NASA) announced that the James Webb Space Telescope has discovered its first new exoplanet.

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Researchers have labelled the planet as LHS 475 b, and it’s roughly the same size as Earth.
Located just 41 light-years away, the planet orbits very close to a red dwarf star and completes a full orbit in just two days.

What are exoplanets?

Exoplanets are planets that orbit other stars and are beyond our solar system.
To date, more than 5,000 exoplanets have been discovered.
Scientists believe that there are more planets than stars as each star has at least one planet orbiting it.
Exoplanets differ in size. They can be gas giants bigger than Jupiter or as small and rocky as Earth.
They are also known to have different kinds of temperatures — boiling hot to freezing cold.

How are exoplanets discovered?

Discovering exoplanets is quite tough as they are small and hard to spot around their bright host stars.
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 methods include direct imaging, astrometry, radial velocity, transit event observation, and microlensing.

What are red dwarf stars?

A red dwarf is the smallest and coolest kind of star in the main sequence.
Red dwarfs are by far the most common type of star in the Milky Way, at least in the neighbourhood of the Sun, but because of their low luminosity, individual red dwarfs cannot be easily observed.
From Earth, not one star that fits the stricter definitions of a red dwarf is visible to the naked eye.
Proxima Centauri, the nearest star to the Sun, is a red dwarf, as are fifty of the sixty nearest stars.
According to some estimates, red dwarfs make up three-quarters of the stars in the Milky Way.