JWST Observes Flares Around Sagittarius A* Black Hole
Why in the news
The James Webb Space Telescope delivered its sharpest view yet of Sagittarius A*, the supermassive black hole at the Milky Way’s centre, revealing constant dynamic activity.
Key facts
- Distance: about 26,000 light years from Earth.
- Its accretion disk flickers continually and produces one to three large flares per 24 hours.
- Observation: seven sessions of 6 to 9.5 hours, just under 48 hours in total over the year.
- The black hole swallows roughly 90% of disk material; the rest is thrown into space.
- Flares probably arise like solar flares, as blobs of turbulent, magnetised gas squeeze against each other.
Comparison
Sgr A* is “quieter” than turbulent black holes in other galaxies. Its disk likely forms from stellar winds of nearby stars, not from a star torn apart.
Background
- JWST: the largest space telescope, orbiting the Sun and studying infrared light to learn about the universe’s origins.
- Black hole: a compact, massive object so dense that even light cannot escape its gravity.
Significance
The work improves understanding of how black holes shape evolution of surrounding matter.
Exam angle
- Sgr A*: supermassive black hole at the Milky Way centre.
- JWST works mainly in infrared.