Bebhionn (moon)


Bebhionn imaged by the Cassini spacecraft in May 2017
Discovered byScott S. Sheppard
David C. Jewitt
Jan T. Kleyna
Brian G. Marsden
Discovery date2004
Pronunciation/ˈbvɪn, ˈbɛviɒn/ BAY-vin, BEV-ee-on
Named after
S/2004 S 11
Orbital characteristics[1]
17119000 km
−834.8 days
Satellite ofSaturn
GroupGallic group
Physical characteristics
Mean diameter
16.33±0.03 h[2]

Bebhionn (/ˈbvɪn, ˈbɛviɒn/), also known as Saturn XXXVII, is a small, irregular natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on 4 May 2005 from observations taken between 12 December 2004 and 9 March 2005.

Bebhionn is about 6 kilometres in diameter and orbits Saturn at an average distance of 16,898 Mm in 820.130 days at an inclination of 41° to the ecliptic (18° to Saturn's equator) and with an eccentricity of 0.333. The rotation period of Bebhionn was measured at 16.33±0.03 hours by the ISS camera of the Cassini spacecraft.[2][3]


The moon was named in April 2007 after Béibhinn (Béḃinn), an early Irish goddess of birth, who was renowned for her beauty. In Irish, Béibhinn/Béḃinn is pronounced [ˈbʲeːvʲiːn̠ʲ] (southern accents, English approximation /ˈbvn/ BAY-veen) or [ˈbʲeːvʲɪn̠ʲ] (northern accents, English approximation /ˈbvɪn/ BAY-vin). The spelling "bh" (older "") indicates that the second consonant is softened to a "v" sound. The extra "o" in the unusual spelling Bebhionn suggests that the final "nn" should be broad [n̪ˠ], but is not itself pronounced. The name is still pronounced as a compound (and thus sometimes spelled Bé Binn etc.), so the unstressed vowel is not reduced to a schwa.


  1. ^ S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
  2. ^ a b c Denk, T.; Mottola, S. (2019). Cassini Observations of Saturn's Irregular Moons (PDF). 50th Lunar and Planetary Science Conference. Lunar and Planetary Institute.
  3. ^ T. Denk, S. Mottola, et al. (2011): Rotation Periods of Irregular Satellites of Saturn. EPSC/DPS conference 2011, Nantes (France), abstract 1452.
  • Institute for Astronomy Saturn Satellite Data
  • Jewitt's New Satellites of Saturn page May 3, 2005 (includes discovery images)
  • IAUC 8523: New Satellites of Saturn May 4, 2005 (discovery)
  • MPEC 2005-J13: Twelve New Satellites of Saturn May 3, 2005 (discovery and ephemeris)
  • IAUC 8826: Satellites of Jupiter and Saturn April 5, 2007 (naming the moon)