Aegir (// EYE-eer) or Saturn XXXVI (provisional designation S/2004 S 10) is a natural satellite of Saturn. Its discovery was announced by Scott S. Sheppard, David C. Jewitt, Jan Kleyna, and Brian G. Marsden on May 4, 2005, from observations taken between December 12, 2004, and March 11, 2005.
Aegir is about 6 kilometres in diameter, and orbits Saturn at an average distance of 19,618 Mm in 1025.908 days, at an inclination of 167° to the ecliptic (140° to Saturn's equator), in a retrograde direction and with an eccentricity of 0.237.
It was named in April 2007 after Ægir, a giant from Norse mythology, the personification of tranquil seas, the one who soothes storms away. He is a son of Fornjót, and brother of Logi (fire, flame) and Kári (wind).
- Institute for Astronomy Saturn Satellite Data
- Jewitt's New Satellites of Saturn page
- 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)