Discovery | |
---|---|
Discovered by | Erich Karkoschka / Voyager 2 |
Discovery date | May 18, 1999 (in images dating back to January 18, 1986) |
Designations | |
Designation | Uranus XXV |
Pronunciation | /ˈpɜːrdətə/ [1] |
Adjectives | Perditean /pɜːrdəˈtiːən/ [2] |
Orbital characteristics | |
Mean orbit
radius | 76,417 ± 1 km [3] |
Eccentricity | 0.0012 ± 0.0005 [3] |
0.638021 ± 0.000013 d [3] | |
Inclination | 0.0 ± 0.3° (to Uranus' equator) [3] |
Satellite of | Uranus |
Physical characteristics | |
13.3±0.7 km [4] | |
~2220 km2 [a] | |
Volume | ~9850 km3 [a] |
Mass | ~(4.93–8.87)×1015 kg [a] |
Mean
density | 0.5–0.9 g/cm3 [5] [6] |
~0.002–0.003 m/s2 [a] | |
~0.007–0.009 km/s [a] | |
synchronous [3] | |
zero [3] | |
Albedo | 0.08 ± 0.01 (assumed) [7] |
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. [3] [8] But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001. [9] 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. [7] [10]
Following its discovery in 1999, it was given the temporary designation of S/1986 U 10. [8] 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. [11]
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. [12] It is also close to an 8:7 resonance with Rosalind. [3] [7]
Perdita belongs to the Portia group of satellites, which also includes Bianca, Cressida, Desdemona, Portia, Juliet, Cupid, Rosalind, and Belinda. [13] These satellites have similar orbits and photometric properties. [13] Little is known about Perdita apart from its orbit, [3] [7] radius of 13.3 km, [4] and geometric albedo of 0.08. [13] [7]
Discovery | |
---|---|
Discovered by | Erich Karkoschka / Voyager 2 |
Discovery date | May 18, 1999 (in images dating back to January 18, 1986) |
Designations | |
Designation | Uranus XXV |
Pronunciation | /ˈpɜːrdətə/ [1] |
Adjectives | Perditean /pɜːrdəˈtiːən/ [2] |
Orbital characteristics | |
Mean orbit
radius | 76,417 ± 1 km [3] |
Eccentricity | 0.0012 ± 0.0005 [3] |
0.638021 ± 0.000013 d [3] | |
Inclination | 0.0 ± 0.3° (to Uranus' equator) [3] |
Satellite of | Uranus |
Physical characteristics | |
13.3±0.7 km [4] | |
~2220 km2 [a] | |
Volume | ~9850 km3 [a] |
Mass | ~(4.93–8.87)×1015 kg [a] |
Mean
density | 0.5–0.9 g/cm3 [5] [6] |
~0.002–0.003 m/s2 [a] | |
~0.007–0.009 km/s [a] | |
synchronous [3] | |
zero [3] | |
Albedo | 0.08 ± 0.01 (assumed) [7] |
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. [3] [8] But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001. [9] 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. [7] [10]
Following its discovery in 1999, it was given the temporary designation of S/1986 U 10. [8] 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. [11]
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. [12] It is also close to an 8:7 resonance with Rosalind. [3] [7]
Perdita belongs to the Portia group of satellites, which also includes Bianca, Cressida, Desdemona, Portia, Juliet, Cupid, Rosalind, and Belinda. [13] These satellites have similar orbits and photometric properties. [13] Little is known about Perdita apart from its orbit, [3] [7] radius of 13.3 km, [4] and geometric albedo of 0.08. [13] [7]