Current Affairs Today - Current Affairs 2017

हिंदी करंट अफेयर्स प्रश्नोत्तरी 2017 के लिए यहाँ क्लिक करें.

Scientists for first time observe Optical polarisation phenomenon of fast spinning star

Scientists for first time have observed Optical polarisation phenomenon (polarised light emitted by rapidly rotating stars) after it was predicted by Indian astrophysicist and Nobel laureate Subrahmanyan Chandrasekhar 70 years ago.

Optical polarisation phenomenon is a measure of the orientation of the oscillations of a light beam to its direction of travel.

Key Facts

The phenomenon was observed using High Precision Polarimetric Instrument (HIPPI), world’s most sensitive astronomical polarimeter to detect polarised light from Regulus, one of brightest stars in night sky about 79 light years away.

The equipment provided unprecedented insights into star, which is in constellation Leo. It allowed scientists to determine its rate of spinning and orientation in space of star’s spin axis. It was observed that Regulus is rotating so quickly with a spin rate of 96.5% of angular velocity (approximately 320 kilometres per second) for break-up.

Background

Subrahmanyan Chandrasekhar in 1946 had first predicted that some stars could be emitting polarised light from their edges. Based on his idea, Astronomers J Patrick Harrington and George W Collins II predicted in 1968 predicted that polarised light will be emitted by rapidly rotating star because its shape gets distorted into a squished oblate shape as it spins too fast.

Subrahmanyan Chandrasekhar

He was Indian American astrophysicist who was awarded the 1983 Nobel Prize for Physics with William A. Fowler for his theoretical studies of physical processes of importance to structure and evolution of stars. His mathematical treatment of stellar evolution had yielded many of best current theoretical models of later evolutionary stages of massive stars and black holes. The Chandrasekhar limit (maximum mass of a stable white dwarf star) has been named after him.

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BCCI nominates MS Dhoni for Padma Bhushan award

The BCCI has nominated former Indian cricket team captain Mahendra Singh Dhoni (36) for Padma Bhushan, country’s third highest civilian award for his contribution to game. He is only cricketer nominated by BCCI for this years Padma Awards.

Dhoni is one of greatest names in contemporary cricket and has impeccable credentials to his name. He is only Indian captain to record two win at World Cup titles (2011 50-over World Cup and 2007 World T20).

Mahendra Singh Dhoni

He is one of the greatest ODI cricketer with nearly 10,000 runs. He has scored 9737 runs in 302 ODIs besides 4876 runs in 90 Test matches. He has also played 78 T20 Internationals, scoring 1212 runs.

He has 16 international hundreds (6 in Tests and 10 in ODIs) to his name along with 100 international half-centuries. As a wicketkeeper, Dhoni has held 584 catches across formats (256 in Tests, 285 in ODIs and 43 in T20 Internationals). He has also effected 163 stumpings. Dhoni is already a recipient of the prestigious Arjuna, Rajeev Gandhi Khel Ratna and the Padma Shri award.

Cricketers awarded with Padma Bhushan

If Dhoni is conferred with Padma Bhushan, he will be 11th Indian cricketer to get third highest civilian honour. Some of notable international cricketers, who have been recipients of Padma Bhushan are Kapil Dev, Sunil Gavaskar, Rahul Dravid, Chandu Borde, Prof DB Deodhar, Col CK Nayudu, Lala Amarnath and Sachin Tendulkar. The lesser known names also include Raja Bhalindra Singh of Patiala, and Vijaya Anand, Maharaja of Vizianagram.

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