K2 229b

UPSC Exam Preparation: Topic of the Day – K2-229b

K2-229b is a hot, metallic, Earth-sized planet orbiting a dwarf star located 260 million light years away. The planet is over 2.5 times greater than the mass of the Earth and is 20 per cent larger than Earth. It reaches a day side temperature of over 2000 degrees Celsius. It is located very close to its host star (0.012 AU, around a hundredth of the distance between the Earth and the Sun), which itself is a medium-sized active K dwarf in the Virgo Constellation. K2-229b orbits its star every fourteen hours.

How was it discovered?

• K2-229b planet was discovered with the help of the K2 telescope Doppler spectroscopy technique. The technique is also known as the ‘wobble method’ used to discover and characterize this faraway planet.
• The astronomers could predict the existence of this planet due to dips in the light from its host star as the planet orbited it, blocking starlight periodically.
• Post that, the astronomers calculated the size, position and mass of K2-229b by measuring the radial velocity of the star, and finding out how much the starlight ‘wobbles’ during orbit, due to the gravitational tug from the planet, which changes depending on the planet’s size.

Origin of K2-229b:

• K2-229b has numerous potential origins (owing to its dense, metallic nature), and one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares (due to the closeness to the star).
• Another hypothesis states that K2-229b was possibly formed post a huge impact between two giant astronomical bodies in space billions of years ago.

Significance of the discovery:

• Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system might have formed.
• As K2-229b is similar to the planet Mercury in our solar system. Knowing more about the former could potentially reveal more about the latter.