Discovery of Gaia BH3

PRELIMS BITS

Background: Astronomers have identified Gaia BH3, a massive black hole located approximately 2,000 light years away in the Aquila constellation, using the European Space Agency’s (ESA) Gaia spacecraft.

Gaia Spacecraft

Launched in 2013, the Gaia mission aims to map the Milky Way galaxy by observing the movements of billions of stars, providing a detailed picture of our galaxy’s structure.

Astronomical Importance

• Gaia BH3 is notable as the first black hole detected in the outer regions of the Milky Way. Its mass surpasses that of Cygnus X-1, which was previously the largest known black hole in the galaxy.
• Unlike typical black holes, Gaia BH3 does not emit X-rays, suggesting it is not currently pulling in surrounding matter.

Black Hole Discoveries by Gaia Spacecraft

• Gaia BH1: The first black hole discovered by Gaia, situated 1,560 light years away.
• Gaia BH2: A second black hole discovered in 2022, with a mass of 9 solar masses.
• Gaia BH3: The largest stellar-mass black hole found in the Milky Way, weighing in at 33 solar masses, located 2,000 light years away in Aquila.

Stellar-Mass Black Holes

Stellar-mass black holes form from the collapse of massive stars and generally have a mass between 3 and several tens of solar masses.

Detection Techniques

• Doppler Effect: By observing the shift in the star’s light, astronomers can measure its motion and infer the mass of an unseen object (such as a black hole).
• Kepler’s Third Law: This law helps determine the mass of the dark object by studying the velocity of the star’s orbit around it.