red giant stars
Giant star spots, not dust, likely culprit in dimming of Betelgeuse
How black hole jets break out of their galaxies
A computer simulation of the powerful jets generated by supermassive black holes at the centres of the largest galaxies explains why some burst forth as bright beacons visible across the universe, while others fall apart and never pierce the halo of the galaxy. A jet’s hot ionised gas is propelled by the twisting magnetic fields of the central rotating black hole.