Leda (moon)

Leda
Discovery image of Leda taken by the Palomar Observatory in 1974
Discovery[1]
Discovered byCharles T. Kowal
Discovery sitePalomar Observatory
Discovery date14 September 1974
Designations
Designation
Jupiter XIII
Pronunciation/ˈldə/[2]
Named after
Λήδα Lēdā
AdjectivesLedian /ˈldiən/,[3] Ledean /ˈldiən/[4] or /lˈdən/[5]
Orbital characteristics[6]
Epoch 16 February 2017 (JD 2457800.5)
Observation arc42.60 yr (15,561 days)
0.0748405 AU (11,195,980 km)
Eccentricity0.1648788
+242.02 d
137.02571°
1° 29m 14.953s / day
Inclination27.63631° (to ecliptic)
190.18497°
312.92965°
Satellite ofJupiter
GroupHimalia group
Physical characteristics
21.5±1.7 km[7]
Albedo0.034±0.006[7]
Spectral type
C [7]
20.2[8]
12.7[6]

Leda /ˈldə/, also known as Jupiter XIII, is one of the innermost and larger of irregular satellite of Jupiter.

Discovery and Naming

It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974, after three nights' worth of photographic plates had been taken (September 11 through 13; Leda appears on all of them).[1][9]

It was named after Leda, who was raped[10] by Zeus, the Greek equivalent of Jupiter (who came to her in the form of a swan). Kowal suggested the name and the IAU endorsed it in 1975.[11]

Orbit

Leda orbits Jupiter at an average distance of 11,195,980 km in 242.02 days, at an inclination of about 28° to the ecliptic, in a prograde direction and with an eccentricity of 0.165.

Leda belongs to the Himalia group, a prograde group of moons orbiting between 11 and 13 million km from Jupiter at inclinations between 27 and 30°, and eccentricities between 0.11 and 0.24.

Physical characteristics

Leda has a diameter of about 21.5 kilometers, with a measured albedo of about 3,4%,[7] making it the smallest of Jupiter's classic irregular moons.

Like the other members of the Himalia group, the satellite appears gray (color indices B-V=0.66 ± 0,01, R-V=0.43 0,01),[12] which is typical for C-type asteroids.[7]

Origin

Leda probably did not form near Jupiter but was captured by Jupiter later. Like the other members of the Himaila group, which have similar orbits, Leda is probably the remnant of a broken, captured heliocentric asteroid.

See also

References

  1. ^ a b Kowal, C. T.; Aksnes, K.; Marsden, B. G.; Roemer, E. (1974). "Thirteenth satellite of Jupiter". Astronomical Journal. 80: 460–464. Bibcode:1975AJ.....80..460K. doi:10.1086/111766.
  2. ^ "Leda". Lexico UK English Dictionary. Oxford University Press. Archived from the original on 8 May 2021.
  3. ^ Ken Monteith (2007) Yeats and theosophy, p. 10
  4. ^ Wit Pietrzak (2011) Myth, Language and Tradition: A Study of Yeats, Stevens, and Eliot in the Context of Heidegger's Search for Being, p. 70–72
  5. ^ R.W. Chapman (1939) Adjectives from Proper Names, p. 55
  6. ^ a b "M.P.C. 128893" (PDF). Minor Planet Circular. Minor Planet Center. 27 January 2021.
  7. ^ a b c d e Grav, T.; Bauer, J. M.; Mainzer, A. K.; Masiero, J. R.; Nugent, C. R.; Cutri, R. M.; et al. (August 2015). "NEOWISE: Observations of the Irregular Satellites of Jupiter and Saturn" (PDF). The Astrophysical Journal. 809 (1): 9. arXiv:1505.07820. Bibcode:2015ApJ...809....3G. doi:10.1088/0004-637X/809/1/3. S2CID 5834661. 3.
  8. ^ Sheppard, Scott. "Scott S. Sheppard - Jupiter Moons". Department of Terrestrial Magnetism. Carnegie Institution for Science. Retrieved 26 November 2020.
  9. ^ Brian G. Marsden (20 September 1974). "IAUC 2702: Probable New Satellite of Jupiter". International Astronomical Union.
  10. ^ Leda and the Swan
  11. ^ Marsden, Brian G. (7 October 1975). "Satellites of Jupiter". International Astronomical Union.
  12. ^ Graykowski, Ariel; Jewitt, David (5 April 2018). "Colors and Shapes of the Irregular Planetary Satellites". The Astronomical Journal. 155 (4): 184. arXiv:1803.01907. Bibcode:2018AJ....155..184G. doi:10.3847/1538-3881/aab49b. ISSN 1538-3881.