Question: what two factors are key in forming planets and stars

title: Star formation
text: A supermassive black hole at the core of a galaxy may serve to regulate the rate of star formation in a galactic nucleus . A black hole that is accreting infalling matter can become active , emitting a strong wind through a collimated relativistic jet . This can limit further star formation . Massive black holes ejecting radio - frequency - emitting particles at near - light speed can also block the formation of new stars in aging galaxies . However , the radio emissions around the jets may also trigger star formation . Likewise , a weaker jet may trigger star formation when it collides with a cloud . Dwarf