title: Fluorescent hydroxyl emissions from Saturn's ring atmosphere.
abstract: Just before earth passed through Saturn's ring plane on 10 August 1995, the Hubble Space Telescope Faint Object Spectrograph detected ultraviolet fluorescent emissions from a tenuous atmosphere of OH molecules enveloping the rings. Brightnesses decrease with increasing distance above the rings, implying a scale height of about 0.45 Saturn radii (Rs). A spatial scan 0.28Rs above the A and B rings indicates OH column densities of about 10(13) cm(-2) and number densities of up to 700 cm(-3). Saturn's rings must produce roughly 10(25) to 10(29) OH molecules per second to maintain the observed OH distribution.
authors.affiliation: Center for Astrophysical Sciences, Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Hall
authors.forename: P D
authors.initials: PD
authors.lastname: Feldman
authors.forename: J B
authors.initials: JB
authors.lastname: Holberg
authors.forename: M A
authors.initials: MA
authors.lastname: McGrath
mesh_terms: D001272:Atmosphere; D005118:Extraterrestrial Environment; D017665:Hydroxyl Radical / Q000032:analysis*; D018539:Saturn
chemical_list: D017665:Hydroxyl Radical