H II regions

H II regions are areas of ionized hydrogen in space, typically found in star-forming regions of galaxies. The designation "H II" refers specifically to atomic hydrogen (H) that has been ionized, meaning its electrons have been stripped away, resulting in positively charged hydrogen ions (H⁺). These regions are often associated with young, hot stars, particularly O and B type stars, which emit large amounts of ultraviolet (UV) radiation.