At https://phys.org/print472115260.html … Australian National University scientists have found that Earth is made of the same elements as the Sun but has less of the volatile elements such as hydrogen, helium, and nitrogen. Rocky planets around stars may be devolatised pieces left over after the formation of stars.
At https://phys.org/print472317628.html … the centre of the Milky Way is a frenzy of activity. A massive black hole blasts out energy as it chows down on interstellar debris while neighbouring stars burst into life, and later, explode. Astronomers have discovered two exhaust channels – or galactic centre chimneys. They think they throw matter and energy away from the centre – which avoids being chowed no doubt as it can't then enter the black hole.
… an article in Nature (March 21st 2019) claims the chimneys are in effect exhaust vents (releasing energy from the maelstrom). It seems they pointed cameras on a satellite which detected X-rays. These are said to be emitted by hot gases and are used to map energetic environments in space. What they saw was two plumes of X-rays stretching in opposite directions, it would seem, from the centre of the galaxy (originating in the vicinity of the black hole).