Sagittarius A

NASA’s James Webb Space Telescope (Webb) has recently captured the best view of the supermassive black hole Sagittarius A* at the center of the Milky Way.

• About Sagittarius A*: It is a supermassive black hole at the Milky Way’s center, 26,000 light-years from Earth. It has 4 million times the Sun’s mass and is in a relatively quiescent state.

o Black holes have extreme gravity, preventing light escape, making direct observations difficult.

• About James Webb Space Telescope: Launched in 2021 and began data collection in 2022.

o Webb’s Near-Infrared Camera (NIRCam) provides better infrared sensitivity, capturing continuous brightness measurements at two infrared wavelengths.

• Key Finding: Researchers observed steady flickering light from its accretion disk, with occasional bright flares, revealing the chaotic environment around it.

o Flickering Light: Constant flickering light comes from gas near the event horizon.

o Bright Flares: Large flares occur 1-3 times every 24 hours, with smaller bursts in between.

o Turbulent Accretion Disk: The disk is chaotic and turbulent, with gas compression due to extreme gravity.