1172_Äneas

1172 Äneas

1172 Äneas

Jupiter trojan asteroid

1172 Äneas /ɪˈniːəs/ is a large Jupiter trojan from the Trojan camp, approximately 140 kilometers (90 miles) in diameter. It was discovered on 17 October 1930, by astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[1] The dark D-type asteroid is one of the largest Jupiter trojans and has a rotation period of 8.7 hours.[5] It is named after the Trojan prince Aeneas, from Greek mythology.[3]

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Orbit and classification

Äneas is located in the L5 Lagrangian point, 60° behind Jupiter in the so-called Trojan camp, orbiting in a 1:1 resonance (see Trojans in astronomy).[6] It is also a non-family asteroid of the Jovian background population.[7][16]

It orbits the Sun at a distance of 4.7–5.8 AU once every 11 years and 11 months (4,354 days; semi-major axis of 5.22 AU). Its orbit has an eccentricity of 0.10 and an inclination of 17° with respect to the ecliptic.[4] The body's observation arc begins with its official discovery observation at Heidelberg in October 1930.[1]

Naming

This minor planet was named after the Trojan hero Aeneas from Greek mythology. He is the son of goddess Aphrodite and Anchises after whom 1173 Anchises was named. The official naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 109).[3]

Physical characteristics

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Rotation period

Several rotational lightcurves of Äneas have been obtained since the first photometric observations by William Hartmann in 1988, that gave a period of 8.33 hours, and by Stefano Mottola and Anders Erikson in 1993, using the ESO 1-metre telescope at La Silla Observatory in Chile. Lightcurve analysis gave a rotation period of 8.708±0.009 hours with a brightness variation of 0.27±0.01 magnitude (U=3).[5][15]

In July and August 2008, Susan Lederer at CTIO in Chile, and Robert Stephens at the Goat Mountain Astronomical Research Station (G79) in California, determined a well-defined period of 8.705±0.005 h with an amplitude 0.20 magnitude (U=3).[5][14] Follow-up observations during 2015–2017 by Robert Stephens and Daniel Coley at the Center for Solar System Studies gave three concurring periods of 8.701, 8.681 and 8.7 hours with an amplitude of 0.62, 0.40 and 0.21 magnitude, respectively (U=3/3/3),[11][12][13][lower-alpha 1] while in August 2011, Pierre Antonini reported a period of 11.8 hours based on a fragmentary lightcurve (U=2-).[19]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Äneas measures between 118.02 and 148.66 kilometers in diameter – making it anywhere from the 8th to 4th largest Jupiter trojan – determined from a common absolute magnitude of 8.33 and a surface albedo between 0.037 and 0.059.[8][9][10] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0403 and a diameter of 142.82 kilometers based on an absolute magnitude of 8.33.[5]

More information Largest Jupiter Trojans by survey(A) (mean-diameter in kilometers; YoD: Year of Discovery), Designation ...
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Spectral type

In the Tholen and Barucci classification, Äneas is a dark D-type asteroid, while in the Tedesco classification is as D/P-type asteroid. Its high V–I color index of 0.99 is typical for D-types.[16]

Notes

  1. Lightcurve plots of (1172) Äneas from Jan 2015, Jan 2016 and Dec 2016 (n.a.) by Daniel Coley and Robert Stephens at the Center for Solar System Studies (U80) and (U81). Quality code is 3/3/3 (lightcurve rating at CS3). Summary figures at the LCDB and CS3.

References

  1. [1]
    "1172 Aneas (1930 UA)". Minor Planet Center. Retrieved 13 June 2018.
  2. [2]
    "Aeneas". Merriam-Webster.com Dictionary.
  3. [3]
    Schmadel, Lutz D. (2007). "(1172) Äneas". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 99. doi:10.1007/978-3-540-29925-7_1173. ISBN 978-3-540-00238-3.
  4. [4]
    "JPL Small-Body Database Browser: 1172 Aneas (1930 UA)" (2018-05-22 last obs.). Jet Propulsion Laboratory. Retrieved 13 June 2018.
  5. [5]
    "LCDB Data for (1172) Äneas". Asteroid Lightcurve Database (LCDB). Retrieved 3 March 2018.
  6. [6]
    "List of Jupiter Trojans". Minor Planet Center. 2 February 2018. Retrieved 3 March 2018.
  7. [7]
    "Asteroid (1172) Äneas – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 June 2018.
  8. [8]
    Grav, T.; Mainzer, A. K.; Bauer, J. M.; Masiero, J. R.; Nugent, C. R. (November 2012). "WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy". The Astrophysical Journal. 759 (1): 10. arXiv:1209.1549. Bibcode:2012ApJ...759...49G. doi:10.1088/0004-637X/759/1/49. S2CID 119101711. (online catalog)
  9. [9]
    Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 15 June 2018.
  10. [10]
    Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
  11. [11]
    Stephens, Robert D.; Coley, Daniel R.; French, Linda M. (July 2016). "A Report from the L5 Trojan Camp - Lightcurves of Jovian Trojan Asteroids from the Center for Solar System Studies". The Minor Planet Bulletin. 43 (3): 265–270. Bibcode:2016MPBu...43..265S. ISSN 1052-8091. Retrieved 3 March 2018.
  12. [12]
    Stephens, Robert D. (April 2017). "Lightcurve Analysis of Trojan Asteroids at the Center for Solar System Studies 2016 October - December". The Minor Planet Bulletin. 44 (2): 123–125. Bibcode:2017MPBu...44..123S. ISSN 1052-8091. PMC 7243949. PMID 32455395.
  13. [13]
    Stephens, Robert D.; Coley, Daniel R.; French, Linda M. (July 2015). "Dispatches from the Trojan Camp - Jovian Trojan L5 Asteroids Observed from CS3: 2014 October - 2015 January". The Minor Planet Bulletin. 42 (3): 216–224. Bibcode:2015MPBu...42R.216S. ISSN 1052-8091. Retrieved 3 March 2018.
  14. [14]
    French, Linda M.; Stephens, Robert D.; Lederer, Susan M.; Coley, Daniel R.; Rohl, Derrick A. (April 2011). "Preliminary Results from a Study of Trojan Asteroids". The Minor Planet Bulletin. 38 (2): 116–120. Bibcode:2011MPBu...38..116F. ISSN 1052-8091. Retrieved 3 March 2018.
  15. [15]
    Mottola, Stefano; Di Martino, Mario; Erikson, Anders; Gonano-Beurer, Maria; Carbognani, Albino; Carsenty, Uri; et al. (May 2011). "Rotational Properties of Jupiter Trojans. I. Light Curves of 80 Objects". The Astronomical Journal. 141 (5): 32. Bibcode:2011AJ....141..170M. doi:10.1088/0004-6256/141/5/170.
  16. [16]
    "Asteroid 1172 Äneas". Small Bodies Data Ferret. Retrieved 13 June 2018.
  17. [17]
    Chatelain, Joseph P.; Henry, Todd J.; French, Linda M.; Winters, Jennifer G.; Trilling, David E. (June 2016). "Photometric colors of the brightest members of the Jupiter L5 Trojan cloud". Icarus. 271: 158–169. Bibcode:2016Icar..271..158C. doi:10.1016/j.icarus.2016.01.026.
  18. [18]
    Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. S2CID 53493339.
  19. [19]
    Behrend, Raoul. "Asteroids and comets rotation curves – (1172) Äneas". Geneva Observatory. Retrieved 3 March 2018.
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