Siarnaq (moon)
| Siarnaq | |
|---|---|
| Provisional or systematic name | S / 2000 S 3 |
| Central body | Saturn |
| Properties of the orbit | |
| Major semi-axis | 18,180,000 km |
| Periapsis | 12,400,000 km |
| Apoapsis | 22,700,000 km |
| eccentricity | 0.280 |
| Orbit inclination | 45.81 ° |
| Orbital time | 896.44 d |
| Mean orbital velocity | 1.42 km / s |
| Physical Properties | |
| Albedo | 0.06 |
| Apparent brightness | 20.1 mag |
| Medium diameter | ≈40 km |
| Dimensions | ≈ 3.9 10 16 kg |
| Sidereal rotation | ≈ 10 h 11 min |
| Acceleration of gravity on the surface | ≈0.0065 m / s 2 |
| Escape speed | ≈16.13 m / s |
| discovery | |
| Explorer |
Brett Gladman et al. |
| Date of discovery | October 25, 2000 |
Siarnaq (also Saturn XXIX) is one of the middle outer moons of the planet Saturn .
discovery
The discovery of Siarnaq by a team consisting of Brett Gladman , John J. Kavelaars , Jean-Marc Petit, Hans Scholl , Matthew J. Holman , Brian G. Marsden , Philip D. Nicholson and Joseph A. Burns on recordings from 23 to as of September 29, 2000 was announced on October 25, 2000. Siarnaq initially received the provisional designation S / 2000 S 3 was named the moon after Siarnaq , a goddess of the mythology of the Inuit .
Orbit data
Siarnaq orbits Saturn on an eccentric orbit at an average distance of 18,180,000 km in around 896½ days. The orbital eccentricity is 0.28, with the orbit being inclined by almost 46 ° to the ecliptic , which is practically identical to the Laplace plane at this distance from Saturn .
Siarnaq belongs to the Inuit group of Saturn's moons.
Structure and physical data
The diameter of Siarnaq is estimated to be around 40 km. It has a very dark surface with an albedo of about 0.06, i.e. that is, only about 6% of the incident sunlight is reflected . With an apparent brightness of 20.1 m , it is an extremely faint object. The rotation period of Siarnaq is about 10¼ hours. This makes Siarnaq the one with the shortest day-night cycle of all moons circling around Saturn in a prograde direction. However, at least nine retrograde orbiting Saturn moons have even shorter periods of rotation.
Web links
- IAUC 7513: S / 2000 S 3 and S / 2000 S 4 October 25, 2000 (discovery)
- MPEC 2000-Y14: S / 2000 S 3, S / 2000 S 4, S / 2000 S 5, S / 2000 S 6, S / 2000 S 10 December 19, 2000 (ephemeris)
- MPEC 2001-U42: S / 2000 S 3 October 23, 2001 (rediscovery)
- IAUC 8177: Satellites of Jupiter, Saturn, Uranus August 8, 2003 (numbering and naming)
Individual evidence
- ↑ a b T. Denk, S. Mottola (2019): Studies of irregular satellites: I. Lightcurves and rotation periods of 25 Saturnian moons from Cassini observations. Icarus 322 , 80-102. DOI: 10.1016 / j.icarus.2018.12.040 .
| further inside | Saturn moons | further outside |
| S / 2004 S 12 |
Semi- major axis (km) Siarnaq 17,531,000 |
S / 2004 S 31 |