S/2004 S 7

S/2004 S 7
Discovery [1]
Discovered byScott S. Sheppard et al.
Discovery siteMauna Kea Obs.
Discovery date12 December 2004
Orbital characteristics [2]
Epoch 9 August 2022 (JD 2459800.5)
Observation arc15.61 yr (5,703 days)
0.1441103 AU (21,559,000 km)
Eccentricity0.5743875
–3.24 yr (–1181.80 d)
94.00208°
0° 18m 16.63s / day
Inclination165.04992° (to ecliptic)
14.74072°
127.76280°
Satellite ofSaturn
GroupNorse group
Physical characteristics
≈6 km[3]
Albedo0.04 (assumed)[3]
24.5[3]
15.6[2]

S/2004 S 7 is a 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 8 March 2005.

S/2004 S 7 is about 6 kilometres in diameter, and orbits Saturn at an average distance of 21,559,000 kilometres in about 1,182 days, at an inclination of 165.0° to the ecliptic, in a retrograde direction and with an eccentricity of 0.574.[2][4] Denk et al. (2018) tentatively assigned this moon to the Mundilfari dynamical family, but it may instead be more closely related to Thrymr.[5]

This moon was considered lost[6] until its recovery was announced on 12 October 2022.[2]

References

  1. ^ Discovery Circumstances from JPL
  2. ^ a b c d "MPEC 2022-T127 : S/2004 S 7". Minor Planet Electronic Circular. Minor Planet Center. 12 October 2022. Retrieved 12 October 2022.
  3. ^ a b c S.S. Sheppard (2019), Moons of Saturn, Carnegie Science, on line
  4. ^ Jacobson, R.A. (2007) SAT272 (2007-06-28). "Planetary Satellite Mean Orbital Parameters". JPL/NASA. Archived from the original on 2011-08-10. Retrieved 2008-01-20.{{cite web}}: CS1 maint: numeric names: authors list (link)
  5. ^ Denk, T.; Mottola, S.; Bottke, W. F.; Hamilton, D. P. (2018). "The Irregular Satellites of Saturn". Enceladus and the Icy Moons of Saturn (PDF). Vol. 322. University of Arizona Press. pp. 409–434. Bibcode:2018eims.book..409D. doi:10.2458/azu_uapress_9780816537075-ch020. ISBN 9780816537488.
  6. ^ Jacobson, B.; Brozović, M.; Gladman, B.; Alexandersen, M.; Nicholson, P. D.; Veillet, C. (28 September 2012). "Irregular Satellites of the Outer Planets: Orbital Uncertainties and Astrometric Recoveries in 2009–2011". The Astronomical Journal. 144 (5): 132. Bibcode:2012AJ....144..132J. doi:10.1088/0004-6256/144/5/132. S2CID 123117568.