LONDON, Mar 28: Scientists have discovered a hot, metallic, Earth-sized planet orbiting a dwarf star located 260 million light years away.
Named K2-229b, the 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 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 this star every fourteen hours.
Using the K2 telescope, researchers from Aix-Marseille Universite in France and University of Warwick in the UK employed the Doppler spectroscopy technique – also known as the ‘wobble method’ – to discover and characterise this faraway planet.
The astronomers knew the planet was there due to dips in the light from its host star as it orbited, periodically blocking starlight.
They then 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.
“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 has numerous potential origins, and one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as the planet is so close to its star.
Another possibility is that K2-229b was formed after a huge impact between two giant astronomical bodies in space billions of years ago – much like 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. (agencies)
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SPO-SHOOT-LD JUNIOR
Muskan wins gold as India pip China at top
SYDNEY, Mar 28:
Muskan clinched the gold medal in women’s 25m pistol as India pipped China at the top of the pecking order in the ISSF Junior World Cup here today.
The 16-year-old Indian bested China’s Qin Sihang and Thailand’s Kanyakorn Hirunphoem, who respectively took silver and bronze in the pistol event, the tournament’s penultimate on the final day.
The team gold was won by Muskan, Manu Bhaker and Devanshi Rana, adding to India’s rich medal haul.
India thus upstaged China with 22 medals, including nine gold to China’s eight.
India have also five silver and eight bronze medals.
Muskan’s medal was India’s fourth individual gold in the prestigious tournament.
Muskan — who finished 4th at last year’s ISSF Junior World Championship in Suhl, Germany — took the lead at the end of the sixth round when she nailed a perfect 5-hit series and found herself sitting on a 3-point advantage over her closest rival, China’s Qin Sihang (16).
Muskan successfully defended that lead throughout the rest of the final, taking gold with 35 hits, while Qin finished with 34 and the silver medal around her neck.
It’s the first ISSF medal for both the Indian and the Chinese junior shooter.
The bronze medal was awarded to Thailand’s 16-year-old Kanyakorn Hirunphoem, currently ranked 62nd in the world in this event.
The Thai shooter — silver medallist in the Air Pistol event four days ago — finished with 26 hits and pocketed her second medal in Sydney.
A second Indian finalist — 16-year-old Manu Bhaker — was placed in 4th position with 18 hits, surviving a shoot-off at the end of the sixth series against Zhu Siying (16) of China.
Zhu then took 6th place with 12 hits, while her teammate Xiao Jiaruixuan (15) was placed 5th with 14 hits, in spite of a 2-point penalty given to her for early loading.
Finally, two first-time participants — India’s 18-year-old Arunima Gaur and China’s Li Xue — respectively took the 7th place with 8 hits and 8th place with 7.
The top of the team podium was taken by Bhaker, Muskan and Rana, while their country-mates Gaur, Mahima Turhi Agrawal and Tanu Rawal secured silver.
Thailand’s Hirunphoem, Viramon Kidarn and Luxciga Srinitivoravong were placed 3rd.
Meanwhile, the Indian trio of Anantjeet Singh Naruka, Ayush Rudraraju and Gurnilal Singh Garcha bagged the team silver in men’s junior skeet with a total of 348.
Naruka finished fifth in the individual skeet final. (AGENCIES)
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