45 Eugenia

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45 Eugenia
45 Eugenia VLT (2021), deconvolved.pdf
Discovery [1]
Discovered by H. Goldschmidt
Discovery date27 June 1857
Designations
(45) Eugenia
Pronunciation /jˈniə/ [2]
Named after
Empress Eugénie
1941 BN
Main belt
Adjectives Eugenian
Orbital characteristics [3]
Epoch 26 November 2005 (JD 2453701.5)
Aphelion 440.305 Gm (2.943 AU)
Perihelion 373.488 Gm (2.497 AU)
406.897 Gm (2.720 AU)
Eccentricity 0.082
1638.462 d (4.49 a)
45.254°
Inclination 6.610°
147.939°
85.137°
Known satellites Petit-Prince
S/2004 (45) 1
Physical characteristics
Dimensions232 × 193 × 161 km [4]
305 × 220 × 145 km [5] [6]
Mean radius
94±1 km [7]
107.3±2.1 km [5]
Mass (5.8±0.1)×1018 kg [7]
(5.69±0.1)×1018 kg [4]
(5.8±0.2)×1018 kg [8] [9] [10]
Mean density
1.66±0.07 g/cm3 [7]
1.1±0.1 g/cm3 [4]
1.1±0.3 g/cm3 [9]
Equatorial surface gravity
0.017 m/s² [11]
Equatorial escape velocity
0.071 km/s [11]
Sidereal rotation period
0.2375 d (5.699 h) [12]
117±10°
−30±10° [6]
124±10°
0.065 (calculated) [7]
0.040±0.002 [5]
F [13]
7.46 [5]

    Eugenia (minor planet designation: 45 Eugenia) is a large asteroid of the asteroid belt. It is famed as one of the first asteroids to be found to have a moon orbiting it. It was also the second triple asteroid to be discovered, after 87 Sylvia.

    Contents

    Discovery

    Eugenia was discovered on 27 June 1857 by the Franco-German amateur astronomer Hermann Goldschmidt. [14] His instrument of discovery was a 4-inch aperture telescope located in his sixth floor apartment in the 6th Arrondissement of Paris. [15] It was the forty-fifth minor planet to be discovered. The preliminary orbital elements were computed by Wilhelm Forster in Berlin, based on three observations in July, 1857. [16]

    The asteroid was named by its discoverer after Empress Eugenia di Montijo, the wife of Napoleon III. [14] It was the first asteroid to be definitely named after a real person, rather than a figure from classical legend. [17]

    Physical characteristics

    Eugenia is a large asteroid, with a diameter of 214 km. It is an F-type asteroid, which means that it is very dark in colouring (darker than soot) with a carbonaceous composition. Like Mathilde, its density appears to be unusually low, indicating that it may be a loosely packed rubble pile, not a monolithic object. Eugenia appears to be almost anhydrous. [18] Lightcurve analysis indicates that Eugenia's pole most likely points towards ecliptic coordinates (β, λ) = (-30°, 124°) with a 10° uncertainty, [6] which gives it an axial tilt of 117°. Eugenia's rotation is then retrograde, rotating backward to its orbital plane.

    Satellite system

    Petit-Prince

    In November 1998, astronomers at the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii, discovered a small moon orbiting Eugenia. This was the first time an asteroid moon had been discovered by a ground-based telescope. The moon is much smaller than Eugenia, about 13 km in diameter, and takes five days to complete an orbit around it.

    The discoverers chose the name "Petit-Prince" (formally "(45) Eugenia I Petit-Prince"). This name refers to Empress Eugenia's son, the Prince Imperial. However, the discoverers also intended an allusion to the children's novella The Little Prince by Antoine de Saint-Exupéry, which is about a young prince who lives on an asteroid. [19]

    S/2004 (45) 1

    A second, smaller (estimated diameter of 6 km) satellite that orbits closer to Eugenia than Petit-Prince has since been discovered and provisionally named S/2004 (45) 1. [20] It was discovered by analyses of three images acquired in February 2004 from the 8.2 m VLT "Yepun" at the European Southern Observatory (ESO) Cerro Paranal, in Chile. [21] The discovery was announced in IAUC 8817, on 7 March 2007 by Franck Marchis and his IMCCE collaborators. It orbits the asteroid at about ~700 km, with an orbital period of 4.7 days. [20]

    See also

    Related Research Articles

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    90 Antiope

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    (45) Eugenia I Petit-Prince is the larger, outer moon of asteroid 45 Eugenia. It was discovered in 1998 by astronomers at the Canada-France-Hawaii Telescope on Mauna Kea, Hawaii. Initially, it received the provisional designation S/1998 (45) 1. Petit-Prince was the first asteroid moon to be discovered with a ground-based telescope. Previously, the only known moon of an asteroid was Dactyl, discovered by the Galileo space probe, around 243 Ida.

    216 Kleopatra

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    Siarnaq Moon of Saturn

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    18 Melpomene Main-belt asteroid

    Melpomene is a large, bright main-belt asteroid that was discovered by J. R. Hind on June 24, 1852, and named after Melpomenē, the Muse of tragedy in Greek mythology. It is classified as an S-type asteroid and is composed of silicates and metals.

    87 Sylvia Large asteroid with 2 moons

    Sylvia is the one of the largest asteroids. It is the parent body of the Sylvia family and member of Cybele group located beyond the main asteroid belt. Sylvia was the first asteroid known to possess more than one moon.

    107 Camilla Asteroid with 2 moons

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    130 Elektra Asteroid with 3 moons

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    1089 Tama

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    1313 Berna, provisional designation 1933 QG, is a background asteroid and synchronous binary system from the Eunomian region in the central asteroid belt, approximately 14 kilometers in diameter. It was discovered on 24 August 1933, by Belgian astronomer Sylvain Arend at the Uccle Observatory in Belgium. The assumed S-type asteroid has a longer-than average rotation period of 25.5 hours and is likely elongated in shape. It was named for the Swiss capital of Bern. The discovery of an 11-kilometer-sized companion was announced in February 2004.

    3749 Balam

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    Linus (moon)

    (22) Kalliope I Linus is an asteroid moon that orbits the large M-type asteroid 22 Kalliope. It was discovered on August 29, 2001, by astronomers Jean-Luc Margot and Michael E. Brown with the Keck telescope, in Hawaii. Another team also detected the moon with the Canada-France-Hawaii Telescope on September 2, 2001. Both telescopes are on Mauna Kea. It received the provisional designation S/2001 (22) 1, until it was named. The naming proposal appeared in the discovery paper and was approved by the International Astronomical Union in July 2003. Although the naming proposal referred to the mythological Linus, son of the muse Calliope and the inventor of melody and rhythm, the name was also meant to honor Linus Torvalds, inventor of the Linux operating system kernel, and Linus van Pelt, a character in the Peanuts comic strip.

    3782 Celle, provisional designation 1986 TE, is a bright Vestian asteroid and asynchronous binary system from the inner regions of the asteroid belt, approximately 6.5 kilometers in diameter. It was discovered on 3 October 1986, by Danish astronomer Poul Jensen at the Brorfelde Observatory in Denmark and named after the German city of Celle. The V-type asteroid has a rotation period of 3.84 hours. The discovery of its 2.3-kilometer minor-planet moon was announced in 2003.

    Franck Marchis American astronomer

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    17246 Christophedumas

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    21900 Orus

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    References

    1. "Discovery Circumstances: Numbered Minor Planets". IAU Minor Planet Center. Harvard-Smithsonian Center for Astrophysics. 9 February 2010. Archived from the original on 10 May 2008. Retrieved 12 August 2010.
    2. "Eugenia" . Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
    3. "ASTORB". Orbital elements database. Lowell Observatory.
    4. 1 2 3 Baer, Jim (2008). "Recent Asteroid Mass Determinations". Personal Website. Archived from the original on 2 July 2013. Retrieved 7 December 2008.
    5. 1 2 3 4 "Supplemental IRAS minor planet survey". Planetary Science Institute. Archived from the original on 17 August 2009.
    6. 1 2 3 Kaasalainen, M.; et al. (2002). "Models of Twenty Asteroids from Photometric Data" (PDF). Icarus. 159 (2): 369–395. Bibcode:2002Icar..159..369K. doi:10.1006/icar.2002.6907.
    7. 1 2 3 4 P. Vernazza et al. (2021) VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis. Astronomy & Astrophysics 54, A56
    8. Marchis, F. "synthesis of several observations". Berkeley. Archived from the original on 13 September 2006.
    9. 1 2 Marchis, F.; et al. (2004). "Fine Analysis of 121 Hermione, 45 Eugenia, and 90 Antiope Binary Asteroid Systems With AO Observations". Bulletin of the American Astronomical Society. 36: 1180. Bibcode:2004DPS....36.4602M.
    10. Uncertainty calculated from uncertainties in the orbit of Petit-Prince.
    11. 1 2 On the extremities of the long axis.
    12. "PDS lightcurve data". Planetary Science Institute. Archived from the original on 9 April 2009.
    13. "PDS node taxonomy database". Planetary Science Institute. Archived from the original on 5 August 2009.
    14. 1 2 Schmadel, Lutz D. (2003). Dictionary of minor planet names . Physics and astronomy online library (5th ed.). Springer. p.  19. ISBN   3-540-00238-3.
    15. J. C. (1867). "Memoirs of the Royal Astronomical Society". Memoirs of the Royal Astronomical Society. Priestley and Weale. 36: 155. Retrieved 13 August 2010.
    16. Goldschmidt, H. (July 1857). "New Planet (45)". Monthly Notices of the Royal Astronomical Society . 17: 263–264. Bibcode:1857MNRAS..17..263G. doi: 10.1093/mnras/17.9.263b .
    17. Tobin, William (2003). The life and science of Léon Foucault: the man who proved the earth rotates. Cambridge University Press. p. 301. ISBN   0-521-80855-3.
    18. A. S. Rivkin (2002). "Calculated Water Concentrations on C Class Asteroids" (PDF). Lunar and Planetary Institute. Retrieved 22 May 2008.
    19. William J. Merlin et al., "On a Permanent Name for Asteroid S/1998(45)1". 26 May 2000.
    20. 1 2 Marchis, F.; Baek, M.; Descamps, P.; Berthier, J.; Hestroffer, D.; Vachier, F. (2007). "S/2004 (45) 1". IAU Circular. 8817. Bibcode:2007IAUC.8817....1M.
    21. "IMCCÉ Breaking News". Archived from the original on 27 September 2007. Retrieved 30 April 2019.