Leurini, SilviaSilviaLeuriniMenten, Karl M.Karl M.Menten2020-12-182020-12-182018978-11071924541743-9213http://hdl.handle.net/20.500.12386/28973As first realised in the late 1980s, methanol masers come in two varieties, termed Class I and Class II. While Class II masers had observationally been extensively studied in the past, until recently relatively little attention was paid to Class I methanol masers due to their low luminosities compared to other maser transitions. In this review, we will focus on the recent progress in our understanding of Class I methanol masers both from an observational and from a theoretical point of view.STAMPAenConference paper10.1017/S17439213170107052-s2.0-85060080542https://www.cambridge.org/core/journals/proceedings-of-the-international-astronomical-union/article/physical-properties-of-class-i-methanol-masers/5B42EAAD846BB017167A6100AAC770572018IAUS..336...17LFIS/05 - ASTRONOMIA E ASTROFISICAERC sectors::Physical Sciences and Engineering::PE9 Universe sciences: astro-physics/chemistry/biology; solar systems; stellar, galactic and extragalactic astronomy, planetary systems, cosmology, space science, instrumentation