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Astronomers discovered Gaia BH3, a gigantic black hole near Earth, making it the third such black hole found by the European Space Agency's Gaia telescope.
This discovery adds to a series of black hole findings in our galaxy, helping to expand our understanding of these mysterious objects.
Gaia telescope
It was launched by the European Space Agency (ESA) in December 2013.
It is located 1.5 million kilometres from Earth at the second Sun-Earth Lagrange point (L2).
Gaia Spacecraft contains two optical telescopes that work with three science instruments to precisely determine the location of stars and their velocities, and to split their light into a spectrum for analysis.
It is creating an extraordinarily precise three-dimensional map of nearly two billion objects throughout our Galaxy and beyond, mapping their motions, luminosity, temperature and composition.
It helps identify dark objects, like black holes, by observing the effects of their gravity on nearby stars.
Doppler effect
It was first described in 1842 by Austrian physicist Christian Doppler.
When the source and the signal are in relative motion to each other there is a change in the frequency observed by the observer.
If they are moving closer frequency increases and vice versa.
Light from a moving object is blue-shifted, while light from a moving object is redshifted
The Doppler effect helps astronomers detect the motion of stars near black holes.
As a star orbits a black hole, the light from the star shifts (toward red or blue), revealing its speed and movement.
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