Astronomers have discovered a hot, metallic, planet outside our solar system which is located 260 million light-years away from Earth and very close to its medium-sized active host star K dwarf in the Virgo Constellation.
Named K2-229b, the newly spotted planet is almost 20 per cent larger than Earth but has a mass which is over two-and-a-half times greater. It reaches a dayside temperature of over 2000 C (2330 Kelvin) and orbits its host star every fourteen hours. The exoplanet has the same high density as Mercury.
The global team of researchers from Aix-Marseille Universite in France and the University of Warwick in the UK spotted K2-229b using the K2 telescope. They employed the Doppler spectroscopy technique, also popularly known as the wobble method, to discover the faraway planet.
The astronomers got the clue of the exoplanet by dips in the light from its host star as it orbited, periodically blocking starlight. The next step was to calculate K2-229b’s size, position, and mass by measuring the radial velocity of the star, and finding out how much the starlight it wobbles during orbit.
“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,” David Armstrong from the University of Warwick said.
He added that K2-229b is probably the innermost planet in the system of at least three planets, though all three orbit much closer to their star than Mercury. Notably, the scientists have come with a number of possible reasons which might have resulted in the planet’s dense and metallic nature.
While one hypothesis is that intense stellar wind and flares would have eroded the planet’s atmosphere, as the planet is so close to its star, the other possibility is that K2-229b might have been formed after two giant astronomical bodies collided in space billions of years ago.
More information about K2-229b is expected to throw light on the origin of the planets in our own solar system. Furthermore, as the newly discovered planet is similar to Mercury, knowing more about it can potentially reveal more about Mercury’s origin.