TWIN
STARS – SCI & TECH
News:
Cosmic Cannibalism:
Astronomers Discover 'Twin' Stars That Eat Planets
What's
in the news?
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Recently, researchers analysed 91 star
pairs from the same birth cloud, sharing similar sizes and compositions.
Key
takeaways:
●
The planetary system that includes Earth
and its sibling planets orbiting the sun has been remarkably stable during its
roughly 4.5 billion years of existence.
●
But not
all planetary systems are stable, as shown in a new study involving
"twin" stars.
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An international research team used three
huge telescopes to look at 91 pairs of twin stars and found some showed
evidence of 'ingesting' planets.
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Scientists had presumed the twin stars would have identical
compositions but surprisingly found that around eight percent of them differ
from the others.
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This difference lies in one of the stars
showing a tendency to 'devour' planets or planetary material.
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The researchers found this phenomenon of
cosmic cannibalism appearing in around 7 of the 91 pairs of twin stars they
looked at.
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All these stars were also in their prime
of life - being so-called 'main sequence' stars - rather than stars in their
final phases of life such as red giants.
Twin
Stars:
●
The study looked at pairs of stars that formed within the same interstellar cloud
of gas and dust - so-called co-natal
stars - giving them the same chemical makeup, and were of roughly equal
mass and age. These are the "twins."
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While the pairs are moving together in the same direction within the Milky Way Galaxy, they
are not binary systems of two stars gravitationally bound to each other.
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In seven of the pairs, one of the two
stars bore evidence of planetary ingestion.
Reasons
Behind ‘Cosmic Cannibalism’:
●
The orbital disturbance caused by a larger
planet, or another star passing uncomfortably close, destabilizing the
planetary system.
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The study focused on stars with comparable
ages and masses, not gravitationally bound but moving in the same galactic
direction.
●
Disparities
in chemical signatures, such as increased levels of iron,
nickel, or titanium, hinted at a star ingesting a planet.
Telescope
Used:
●
The researchers used the European Space Agency's Gaia space
observatory to identify the twins and used telescopes in Chile and Hawaii
to determine their composition.
Important
takeaways:
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The stars were as close as 70 light years
from our solar system and as far as 960 light years away.
●
A light year is the distance light travels
in a year, 5.9 trillion miles (9.5 trillion km).
Binary
Star:
●
A binary star or binary star system is a
system of two stars that are gravitationally
bound to and in orbit around each other.
●
Binary stars in the night sky that are
seen as a single object to the naked eye are often resolved using a telescope
as separate stars, in which case they are called visual binaries.