Perdita (moon)

Perdita
Discovery
Discovered byErich Karkoschka / Voyager 2
Discovery dateMay 18, 1999 (in images dating back to January 18, 1986)
Designations
Designation
Uranus XXV
Pronunciation/ˈpɜːrdətə/[1]
AdjectivesPerditean /pɜːrdəˈtən/[2][3]
Orbital characteristics
Mean orbit radius
76,417 ± 1 km[4]
Eccentricity0.0012 ± 0.0005[4]
0.638021 ± 0.000013 d[4]
Inclination0.0 ± 0.3° (to Uranus' equator)[4]
Satellite ofUranus
Physical characteristics
13.3±0.7 km[5]
~2220 km2[a]
Volume~9850 km3[a]
Mass~(4.93–8.87)×1015 kg[a]
Mean density
0.5–0.9 g/cm3[6][7]
~0.002–0.003 m/s2[a]
~0.007–0.009 km/s[a]
synchronous[4]
zero[4]
Albedo0.08 ± 0.01 (assumed)[8]
Temperature~64 K[a]

Perdita /ˈpɜːrdətə/ is an inner satellite of Uranus. Perdita's discovery was very complicated, as the first photographs of Perdita were taken by the Voyager 2 spacecraft in 1986, but it was not recognized from the photographs for more than a decade. In 1999, the moon was noticed by Erich Karkoschka and reported.[4][9] But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001.[10] However, in 2003, pictures taken by the Hubble Space Telescope managed to pick up an object where Perdita was supposed to be, finally confirming its existence.[8][11]

Following its discovery in 1999, it was given the temporary designation of S/1986 U 10.[9] It was named Perdita (Latin for 'lost') after the daughter of Leontes and Hermione in William Shakespeare's play The Winter's Tale. The moon is also designated Uranus XXV.[12]

Discovery image of Perdita taken by Voyager 2 on 23 January 1986. The location of the moon is indicated by the arrow on the upper right.

The moon orbits between Belinda and Puck. The above-mentioned Hubble measurements prove that Perdita does not follow a direct Keplerian motion around Uranus. Instead, it is clearly caught in a 43:44 orbital resonance with the nearby moon Belinda, and from this resonance it has been determined that Belinda's mass is 26 times that of Perdita.[13] It is also close to an 8:7 resonance with Rosalind.[4][8]

Perdita belongs to the Portia group of satellites, which also includes Bianca, Cressida, Desdemona, Portia, Juliet, Cupid, Rosalind, and Belinda.[14] These satellites have similar orbits and photometric properties.[14] Little is known about Perdita apart from its orbit,[4][8] radius of 13.3 km,[5] and geometric albedo of 0.08.[14][8]

  1. ^ Benjamin Smith (1903). The Century Dictionary and Cyclopedia.
  2. ^ Byrne (2008). Perdita: the literary, theatrical, scandalous life of Mary Robinson.
  3. ^ J. B. Lethbridge (2013) Shakespeare and Spenser: Attractive opposites.
  4. ^ a b c d e f g h i Karkoschka, Voyager 2001.
  5. ^ a b Showalter & Lissauer (2006),[8] as cited in Ćuk et al. (2022).[7]
  6. ^ French & Showalter 2012.
  7. ^ a b Ćuk et al. 2022.
  8. ^ a b c d e f Showalter & Lissauer 2006.
  9. ^ a b IAUC 7171.
  10. ^ Foust 2001.
  11. ^ IAUC 8194.
  12. ^ USGS: Planet and Satellite Names and Discoverers.
  13. ^ French, Robert S.; Showalter, Mark R.; de Pater, Imke; Lissauer, Jack J. (2017-10-01). Orbital and Photometric Analysis of the Inner Uranian Satellites from Hubble Images. Vol. 49. p. 214.19.
  14. ^ a b c Karkoschka, Hubble 2001.


Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).