S / 2004 S 39

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S / 2004 S 39
Central body Saturn
Properties of the orbit
Major semi-axis 23,574,814 km
Periapsis 21,680,089 km
Apoapsis 25,469,538 km
eccentricity 0.0804
Orbit inclination 166.58 °
Orbital time 1351.41 d
Mean orbital velocity 1.258 km / s
Physical Properties
Apparent brightness 25.5 mag
Medium diameter 2 km
Acceleration of gravity on the surface ≈ 0 m / s 2
Escape speed ≈ 0 m / s
discovery
Explorer

Scott S. Sheppard
David C. Jewitt
Jan T. Kleyna

Date of discovery December 12, 2004

S / 2004 S 39 is one of the smaller outer moons of the planet Saturn .

Discovery and naming

S / 2004 S 39 was discovered on December 12, 2004 by the astronomers Scott Sheppard and David Jewitt ( University of California ) and Jan Kleyna ( University of Hawaii ) on images taken from December 12, 2004 to March 22, 2007 with the 8.2 m Subaru telescope at the Mauna Kea Observatory . From this period 19 more moons of Saturn could be detected; the discovery was announced on October 8, 2019, the moon was given the provisional designation S / 2004 S 39 .

The Carnegie Institution for Science called with the announcement of the discovery on the public to to 6 December 2019 to send in suggestions for names for a total of 20 newly discovered moons. According to the group affiliation of the moons, names of giants from the Gallic , Nordic or Inuit mythology should be used.

The observation period of S / 2004 S 39 extends from December 12, 2004 to March 21, 2007; there are a total of 18 observations over a period of three years.

Track properties

S / 2004 S 39 orbits Saturn in three years and 256.4 days on a slightly elliptical, retrograde orbit between 21,680,089 km and 25,469,538 km from its center. The orbit eccentricity is 0.080, the orbit is inclined 166.6 ° in relation to the equator of Saturn .

The moon is part of the so-called Nordic group of Saturn moons, which orbit the planet with orbital inclinations between 145.2 ° and 177.5 ° and orbital eccentricities between 0.130 and 0.580 retrograde.

Physical Properties

S / 2004 S 39 has a diameter of about 2 km. The absolute brightness of the moon is 16.3  m .

See also

Web links

Individual evidence

  1. v ≈ π * a / period (1 + sqrt (1-e²))
  2. ^ Scott S. Sheppard : Saturn Moons . Carnegie Institution for Science . Retrieved October 10, 2019.
  3. MPC : MPEC 2019-T161: S / 2004 S 39 . IAU . October 8, 2019. Retrieved October 10, 2019.
further inside Saturn moons further outside
Surtur
Semi- major axis  (km) S / 2004 S 39 22,790,400
Ymir