Astronomy Current Affairs

K2-229b: Hot, metallic Earth-sized planet discovered

Scientists using Kepler 2 telescope have discovered hot, metallic, Earth-sized planet named K2-229b orbiting dwarf star located 260 million light years away. They had employed Doppler spectroscopy technique also known as ‘wobble method‘ to discover and characterise this faraway planet.

K2-229b

K2-229b planet is almost 20% larger than Earth but has mass which is over two-and-a-half times greater. It is located very close to its host star (0.012 AU, around a hundredth of the distance between Earth and Sun), which itself is medium-sized active K dwarf in Virgo Constellation.

K2-229b orbits its star every fourteen hours. Its day side temperature reaches over 2000 degrees Celsius. Scientists calculated size, position and mass of K2-229b by measuring radial velocity of star and finding out starlight ‘wobbles’ during orbit, due to gravitational tug from planet, which changes depending on planet’s size.

K2-229b has same high density that of Mercury-like planets. It is also innermost planet in system of at least three planets, though all three orbit much closer to their star than Mercury.

Significance

The dense, metallic nature of K2-229b has numerous potential origins. The one hypothesis is that its atmosphere might have been eroded by intense stellar wind and flares, as it is so close to its star. Another possibility is that K2-229b was formed after huge impact between two giant astronomical bodies in space billions of years ago – much like theory that Moon was formed after Earth collided with body size of Mars. K2-229b is similar to Mercury, knowing more about it can potentially give more clues of formation our planets in our own solar system.

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Proxima Centauri may host planetary system: Study

Scientists have detected dust belts around Proxima Centauri, a finding that indicates presence of elaborate planetary system hosted by closest star to solar system. These new observations were made by Atacama Large Millimeter Array (ALMA) observatory in Chile.

Key Facts

The new observations reveal emission from clouds of cold cosmic dust surrounding star. It revealed glow coming from cold dust in region between one to four times as far from Proxima Centauri as Earth is from Sun. It also reveals presence of even cooler outer dust belt and may indicate presence of system of planets. These structures are similar to much larger belts in solar system and are also expected to be made from particles of rock and ice that failed to form planets.

Proxima Centauri

It is closest star to Sun around 4.25 light years away from the Earth. It is faint red dwarf lying just four light years away in southern constellation of Centaurus. It hosts an Earth-like habitable planet — Proxima Centaur b — orbiting within (Proxima Centauri) its habitable zone which was discovered in 2016.

ALMA Observatory

Atacama Large Millimetre/submillimetre Array (ALMA) Observatory is array of radio telescopes being deployed in Chile. It is composed of 66 high precision antennas that allow scientists to unravel important astronomical mysteries, in search of our Cosmic Origins. One of its goals is to image black hole.

It is an international partnership of European Southern Observatory (ESO), US National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan, together with NRC (Canada), NSC and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with Chile.

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