Scientists discover hot Earth-sized planet K2-229b outside our solar system
New Delhi : There is a new discovery in our milky way. Scientists have discovered an Earth-sized planet orbiting a dwarf star located 260 million light years away. The planet is said to be hot and metallic and has been named as K2-229b.
The newly discovered planet has been named K2-229b and is almost 20 per cent larger than Earth but has a mass which is two-and-a-half times greater than our planet. It attains a day side temperature of over 2000 degrees Celsius.
K2-229b is situated 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 this dwarf star every 14 hours.
As the name suggest, scientists have discovered K2-229b using the K2 telescope. A team of researchers from Aix-Marseille Universite in France and the University of Warwick in the UK have used the Doppler spectroscopy technique - also known as the 'wobble method' - to discover and characterise this remote planet.
The astronomers believe that the planet was there due to dips in the light from its host star as it orbited, periodically blocking the light emitting from the star.
They 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 alters depending on the size of the planet.
"Mercury stands out from the other Solar System terrestrial planets, showing a very high fraction of iron and implying it formed in a different way," said David Armstrong from the University of Warwick.
"We were surprised to see an exoplanet with the same high density, showing that Mercury-like planets are perhaps not as rare as we thought," Armstrong said.
"Interestingly K2-229b is also the innermost planet in a system of at least three planets, though all three orbit much closer to their star than Mercury," he said.
The dense, metallic nature of K2-229b is believed to have potential origins. One assumption is that its atmosphere might have been wrinkled by intense stellar wind and flares, as the planet is so close to its star.
Another hypothesis is that K2-229b was formed after an enormous collision between two giant astronomical bodies in space billions of years ago, alike the theory that the Moon was formed after Earth collided with a body the size of Mars.
Discovering details about far-flung planets across the universe gives us more clues as to how planets in our own solar system formed, researchers said.
As K2-229b is similar to Mercury, knowing more about the former can potentially reveal more about the latter, they said.