Comet IRAS-Araki-Alcock
Right ascension: 8:56:55 Magnitude: 2.4
Declination: 27:06:16
Image: LWR 15909
Date: 1983 May 11 20:28 UT
Exposure duration: 100 min
IUE observed Comet IRAS-Araki-Alcock (1983d) as the comet passed less than 5
million kilometers from Earth, the closest approach of a comet since Comet
Lexell in 1770. IUE detected molecular sulfur (S2) for the first time in any
celestial object (the seven emission lines to the upper left of the bright OH
line at lower right). Carbon monosulfide is also visible in the spectrum.
A long-period comet, it shows characteristically spherical distribution of
outgassing. Shorter-period comets, which have lost many of their volatiles
over the course of repeated solar exposures, have more localized jets or
geysers.
Last updated: 08 April 1998
Obtained from IUE project at Goddard Space Flight Center