Erriapus , or Saturn XXVIII (28), is a
prograde irregular satellite
In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, orbital inclination, inclined, and often orbital eccentricity, eccentric and Retrograde and prograde motion, retrograd ...
of
Saturn
Saturn is the sixth planet from the Sun and the second-largest in the Solar System, after Jupiter. It is a gas giant with an average radius of about nine and a half times that of Earth. It has only one-eighth the average density of Earth; h ...
. It was discovered by
Brett Gladman
Brett James Gladman (born April 19, 1966) is a Canadian astronomer and a full professor at the University of British Columbia's Department of Physics and Astronomy in Vancouver, British Columbia. He holds the Canada Research Chair in planetary a ...
,
John J. Kavelaars and colleagues in 2000, and given the temporary designation S/2000 S 10. It was named Erriapo in August 2003 after ''Erriapus'' (also rendered ''Erriappus''), a giant in
Gaulish mythology
Celtic mythology is the body of myths belonging to the Celtic peoples.Cunliffe, Barry, (1997) ''The Ancient Celts''. Oxford, Oxford University Press , pp. 183 (religion), 202, 204–8. Like other Iron Age Europeans, Celtic peoples followed ...
; the name was changed from
dative
In grammar, the dative case (abbreviated , or sometimes when it is a core argument) is a grammatical case used in some languages to indicate the recipient or beneficiary of an action, as in "Maria Jacobo potum dedit", Latin for "Maria gave Jacob a ...
''Erriapo'' to
nominative
In grammar, the nominative case (abbreviated ), subjective case, straight case or upright case is one of the grammatical cases of a noun or other part of speech, which generally marks the subject of a verb or (in Latin and formal variants of Engl ...
''Erriapus'' per
IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
conventions in late 2007.
IAUC 9191: ''SATURN XXVIII (ERRIAPUS)''
January 11, 2011
Erriapus is about 10 kilometres in diameter, and orbits Saturn at an average distance of 17.3 Gm in 871 days.
As a member of the Gallic group
The Gallic group is a dynamical grouping of the prograde irregular satellites of Saturn following similar orbits. Their semi-major axes range between 16 and 19 Gm, their inclinations between 35° and 40°, and their eccentricities around 0.53. ...
of irregular satellites, which share similar orbital characteristics and a light-red colour, Erriapus is hypothesized to have its origin in the break-up of a common progenitor of the group,[Gladman, B. J.; Nicholson, P. D.; Burns, J. A.; Kavelaars, J. J.; Marsden, B. G.; Holman, M. J.; Grav, T.; Hergenrother, C. W.; Petit, J.-M.; Jacobson, R. A.; and Gray, W. J.]
''Discovery of 12 satellites of Saturn exhibiting orbital clustering''
Nature, 412 (July 12, 2001), pp. 163–166 or to be a fragment of its largest member, Albiorix.[Grav, T.; and Bauer, J.]
''A deeper look at the colors of Saturnian irregular satellites''
/ref> With a rotation period of and an elongated shape, it is a candidate for a contact binary
In astronomy, a contact binary is a binary star system whose component stars are so close that they touch each other or have merged to share their gaseous envelopes. A binary system whose stars share an envelope may also be called an overcontac ...
or binary moon.
References
*Ephemeri
from IAU-MPC NSES
External links
{{DEFAULTSORT:Erriapus (Moon)
Gallic group
Moons of Saturn
Irregular satellites
Astronomical objects discovered in 2000
Moons with a prograde orbit