🌐EnglishEnglishDeutschEspañolFrançaisItalianoNederlandsPolskiPortuguêsРусский한국어中文日本語EntityQ1504097· pop 15· linked from 236 articlesStrömgren spheresphere of ionized hydrogen around a young star of the spectral classes O or BAvailable in 15 languagesEspañolFrançaisDeutsch中文日本語РусскийPortuguêsItalianoGreekLithuanianConnectionsionizationEntitystarEntityCategories1939 in scienceConcepts in astrophysics