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Astronomers Just Found a Black Hole Near Earth.

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An artist’s impression depicts the orbits of the two stars and the black hole in the HR 6819 triple system, made up of an inner binary with one star (orbit in blue) and a newly discovered black hole (orbit in red), as well as a third star in a wider orbit (also in blue), in this image released on May 6, 2020.

Astronomers have spotted the closest black hole to Earth ever discovered and are surprised about its living arrangements – residing harmoniously with two stars in a remarkable celestial marriage that may end in a nasty breakup.

The black hole, at least 4.2 times the mass of the sun, is gravitationally bound to two stars in a so-called triple system roughly 1,000 light years from Earth, researchers said on Wednesday.

“Just around the corner” in cosmic terms, said Chile-based European Southern Observatory astronomer Thomas Rivinius, lead author of the study published in the journal Astronomy & Astrophysics.

A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).

Black holes are extraordinarily dense objects possessing gravitational pulls so powerful that not even light can escape. Some are monstrous like the one at our galaxy’s centre 26,000 light years from Earth that is four million times the sun’s mass.

Garden variety so-called stellar-mass black holes like the newly discovered one have the mass of a single star. This one probably began its life as a star up to 20 times the sun’s mass that collapsed into a black hole at the end of its relatively short lifespan.

This triple system, called HR 6819, can be seen from Earth’s southern hemisphere with the naked eye, in the constellation Telescopium. Until now, the closest-known black hole was one perhaps three times further away.

Only a few dozen stellar-mass black holes previously were known. But there may be hundreds of millions or even a billion of them in the Milky Way, said astrophysicist and study co-author Petr Hadrava of the Academy of Sciences of the Czech Republic.

This black hole, detected using an observatory in Chile, is minding its manners and has not shredded its two partners: stars about five or six times the mass of the sun. At least not yet.

“The formation of a black hole is a violent process, and most models would not have predicted a triple system could survive that but rather would fly apart,” Rivinius said.

The black hole forms a pair with one of the two stars, as near to one another as the Earth is to the sun. The other star is much further away, orbiting the pair. This star spins so rapidly that it is misshapen, bulging at the equator.

The two stars are sufficiently distant from the black hole that it is not pulling material from them. But in a few million years the closer star is expected to grow in size as part of its life cycle.

“What happens then is uncertain,” Rivinius said. “The most spectacular outcome would be if the black hole ends up with that star inside it.”

Education

CBSE to reduce syllabus for Classes 9 to 12 by 30%, says HRD Minister.

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Taking into consideration the ongoing corona virus pandemic a and the lockdown imposed in the country, the Center on Tuesday decided to rationalize the syllabus for students of Class 9 to Class 12 studying in the Central Board of Secondary Education (CBSE) board for the academic year 2020-21. Dr Ramesh Pokhriyal Nishank, Union cabinet minister for Human Resource Development tweeted, “Looking at the extraordinary situation prevailing in the country and the world, #CBSE was advised to revise the curriculum and reduce course load for the students of Class 9th to 12th.”

He also informed that a few weeks ago, he had invited suggestions regarding the reduction of the syllabus from educationists and experts and that the Center received more than 1,500 responses. “Considering the importance of learning achievement, it has been decided to rationalize syllabus up to 30 per cent by retaining the core concepts,” he tweeted.
The CBSE also issued a statement regarding the matter which noted that the prevailing health emergency in the country and at different parts of the world as well as the efforts to contain the spread of Covid-19 pandemic has resulted in the loss of classroom teaching due to closure of schools.
Therefore the Board has decided to revise the syllabus for Classes 9 to 12 for the academic session 2020-21. The changes made in the syllabus have been finalized by the respective Course Committees with the approval of the Curriculum Committee and Governing Body of the Board,” the statement read.

It further stated that the heads of the schools and teachers must ensure that the topics that have been reduced are also explained to the students to the extent required to connect different topics. “However, the reduced syllabus will not be a part of the topics for Internal Assessment and year-end Board Examination,” it said.

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