Context : The discovery of hidden black holes near Earth continues to intrigue astronomers, with the European Space Agency’s Gaia telescope playing a pivotal role.
Relevance : GS 3(Science , Technology)
- Gaia’s Contribution: Since 2013, Gaia has been mapping the motions of billions of stars in our galaxy. Among its discoveries are black holes that aren’t emitting X-rays, thus invisible through traditional observation methods.
- New Discovery: Gaia BH3, discovered in 2023, is the largest stellar-mass black hole found in the Milky Way. It has 33 solar masses, surpassing Cygnus X-1 by 12 solar masses. It’s located 2,000 light years away in the Aquila constellation and is not actively pulling in matter.
- Techniques Used: Astronomers infer the existence and mass of these black holes by observing the orbits of nearby stars. If a star orbits an invisible object, its motion—detected by the Doppler effect—helps estimate the mass of the hidden object, revealing whether it’s a black hole.
- Gaia BH1 and BH2: Gaia BH1, discovered in 2022, is the closest black hole to Earth, 1,560 light years away. It was identified by a star orbiting something invisible, moving much faster than expected. Gaia BH2, another discovery, also featured a star orbiting an unseen object, confirming its status as a black hole.
- Implications for Early Universe: The Gaia BH3 discovery provides new insights into black holes formed early in the universe. The size of Gaia BH3 suggests that large stellar-mass black holes were produced soon after the formation of the universe, offering a rare chance to study such objects.
