The external photoevaporation of planet-forming discs

Abstract Planet-forming disc evolution is not independent of the star formation and feedback process in giant molecular clouds. In particular, OB stars emit UV radiation that heats disperses discs a called ‘external photoevaporation’. This understood to be dominant environmental influence acting on planet-forming typical star-forming regions. Our best studied are nearby, sparse stellar groups where external photoevaporation less effective. However, majority expected reside much stronger environments. Understanding therefore key understanding how most evolve, hence, planets form. Here, we review our theoretical observational photoevaporation. We also lay out developments for future address existing unknowns establish full role planet process.