Description

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Context

A “black hole triple” system was discovered, 8,000 light years away from Earth, by researchers from Caltech and MIT, published in Nature.

About the system

The system in question is V404 Cygni, located within the Milky Way and around 8,000 light-years from Earth. This so-called "X-ray binary" of the black hole and its victim star were previously known, and the system has been well-studied.

However, a deeper investigation revealed that this binary actually sits at the heart of a triple star system.

The system comprises:
1. Central Black Hole (V404 Cygni): Nine times the mass of the Sun, consuming a nearby small star.
2. Two Stars: One orbits closely (every 6.5 days) and another orbits from a far distance (every 70,000 years).

It is located in the constellation Cygnus.

Cygnus is a northern constellation on the plane of the Milky Way, deriving its name from the Latinized Greek word for swan. Cygnus is one of the most recognizable constellations of the northern summer and autumn, and it features a prominent asterism known as the Northern Cross.

The formation process is believed to be direct collapse rather than a supernova, which usually ejects outer stars. It involves the star collapsing without an explosion, creating a black hole without expelling matter, leading to a “gentle” implosion.

Significance: Challenges previous black hole formation theories, suggesting some binary black holes may have originally been triple systems where one member was eventually consumed.

What is a black hole?

A black hole is a region in space where the pull of gravity is so strong that no matter or light can escape it. Most black holes are formed after massive stars explode at the end of their lives — known as a supernova. However, the triple system suggests a gentler process.

Black hole formation

Stage of Formation	Description
*1. Stellar Evolution*	Massive stars (greater than 8 times the Sun’s mass) undergo nuclear fusion, burning hydrogen into heavier elements.
*2. Red Supergiant Phase*	The star exhausts its nuclear fuel, expanding and cooling to form a red supergiant.
*3. Iron Core Formation*	Fusion in the core stops once iron forms, as iron fusion consumes energy instead of releasing it.
*4. Core Collapse*	Without energy from fusion, the core collapses under gravity, leading to an intense, rapid inward collapse.
*5. Supernova Explosion*	The collapsing core rebounds, creating a shockwave that expels outer layers in a massive explosion (supernova).
*6. Formation of a Neutron Star or Black Hole*	If the remaining core mass exceeds about 3 solar masses, it continues collapsing into a black hole; otherwise, it forms a neutron star.
*7. Black Hole Singularity and Event Horizon*	The core’s matter is compressed to an infinitely dense point, surrounded by the event horizon, beyond which light cannot escape.

Read about blackholes in detail: https://www.iasgyan.in/daily-current-affairs/black-holes

Sources:

space

PRACTICE QUESTION

Q.Consider the following statements regarding Black Hole formation:

A black hole can form through a process called "direct collapse”.
A "failed supernova" results in a gentle implosion rather than an explosive ejection of matter.
Triple black hole systems are commonly found in nearby galaxies.

Which of the statements given above is/are correct?

A. 1 and 2 only
B. 2 and 3 only
C. 1 and 3 only
D. 1, 2, and 3

Answer: A

Explanation:

Statement 1 is correct: Black holes can form through "direct collapse," where a massive star collapses under its own gravity without an explosive supernova. This is also known as a "failed supernova."

Statement 2 is correct: In a failed supernova, a black hole forms in a "gentle" implosion, without expelling matter.

Statement 3 is incorrect: Triple black hole systems are rare, and most black holes are part of binary systems rather than triples.