BLACK HOLE - GEOGRAPHY
News: International
Study Observes Smaller Black Hole Orbiting Larger One in Distant Galaxy OJ 287
What’s in
the news?
An
international team of 32 scientists from 10 countries (Finland, Poland, India,
China, USA, Czech Republic, Japan, Germany, Spain, and Italy) has made a
groundbreaking discovery by directly observing a smaller black hole orbiting a
larger one in the distant galaxy OJ 287. This marks the first direct
observation of such an event.
Background
- Galaxy OJ 287: Located 4
billion light-years away, this galaxy has garnered attention for its
unique black hole pair.
- Initial
Theory:
The theory of two black holes in OJ 287 was first proposed by astronomers
from the University of Turku, Finland.
- NASA's TESS: In 2021,
NASA's Transiting Exoplanet Survey Satellite (TESS), typically used for
discovering exoplanets, was directed towards OJ 287 to confirm the black
hole pair theory.
Black Hole
About:
- Black holes are regions of
space-time where gravity is so strong that nothing,
not even light, can escape from them.
- They are formed when a massive
star collapses in on itself at the end of its life, creating an
incredibly dense object with a gravitational pull that is so strong that
it warps space-time around it.
Types of Black Holes:
- Stellar Black Hole: It
is formed by the collapse of a single massive star
- Intermediate Black Hole: Their
masses are between 100 and 100,000 times that of the sun.
- Supermassive Black Hole: Their
masses ranging from millions to billions of times that of the sun,
found at the centres of most galaxies including our own Milky Way
galaxy.
Importance:
- Black holes are important
for understanding the universe and its evolution.
- They play a role in
the formation and evolution of galaxies and the
distribution of matter throughout the universe.
- Studying black holes can
also help us understand the fundamental properties of space, time,
and gravity.
Key Findings
- Indirect
Evidence:
Earlier studies suggested the existence of a massive black hole orbiting a
giant black hole that is 100 times its size.
- Direct
Observation:
TESS monitored the brightness of the primary black hole and its jet,
detecting a flare that indicated the presence of the smaller black hole.
- Accretion
Disk Interaction:
The observed flare occurred when the smaller black hole interacted with
the accretion disk of the larger black hole, resulting in a bright jet of
gas.
- Color Change: The jet's
brightness temporarily altered OJ 287's color from red to yellow.
- Future
Prospects:
The smaller black hole is expected to emit nano-Hertz gravitational waves,
which could be detected by pulsar timing arrays in the near future.
This
discovery is significant as it provides direct observational evidence of a
smaller black hole orbiting a larger one, enhancing our understanding of black
hole interactions and their role in the universe.
Source: https://pib.gov.in/PressReleasePage.aspx?PRID=2034082