Astronomy Current Affairs

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.


Scientists detect Gravitational waves for fourth time

Scientists have successfully detected gravitational waves for fourth time coming from merger of two massive black holes. It was for first time, these waves were simultaneously detected by US-based Laser Interferometer Gravitational-wave Observatory (LIGO) and Italy-based Virgo detectors. The first two detection were made in September and December 2015 in quick succession and for third time it was detected in January 2017.

Key Facts

The recently detected gravitational waves were emitted during final moments of merger of two black holes  located about 1.8 billion light-years away with masses about 31 and 25 times mass of Sun. The newly produced spinning black hole has about 53 times mass of our sun i.e. about 3 solar masses were converted into gravitational-wave energy during merger.

Gravitational Waves

Gravitational waves are ripples curvature of spacetime which propagate as waves, travelling outward from source at the speed of light. They transport energy as gravitational radiation and pass through matter without interacting with it. Gravitational waves were first predicted in 1916 by Albert Einstein on the basis of his Theory of General Relativity. Strongest sources of gravitational waves are among enigmatic objects in our universe like black holes, supernova, neutron stars and Big Bang. Information extracted by these transmitted waves may help to address unsolved questions and mysteries of physics and astronomy.

Note: Russel Hulse and Joseph Taylor had discovered indirect evidence for existence of gravitational waves emitted from decaying orbital period of objects called binary pulsars in 1974,. Both of them for their discovery were awarded the Nobel Prize in Physics in 1993.