1160 Illyria, provisional designation 1929 RL, is a stony Maria asteroid from the central regions of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 9 September 1929, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[15] The asteroid was named after the ancient region of Illyria, located on the Balkan Peninsula.[3]

1160 Illyria
Modelled shape of Illyria from its lightcurve
Discovery[1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date9 September 1929
Designations
(1160) Illyria
Pronunciation/ɪˈlɪriə/[2]
Named after
Illyria (region on the Balkans)[3]
1929 RL · 1962 WA
main-belt · (middle)
Eunomia[4] · Maria[5]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.73 yr (32,045 days)
Aphelion2.8628 AU
Perihelion2.2591 AU
2.5610 AU
Eccentricity0.1179
4.10 yr (1,497 days)
166.36°
0° 14m 25.8s / day
Inclination14.963°
3.7920°
4.6994°
Physical characteristics
Dimensions12.73±1.07 km[6]
13.85±0.49 km[7]
13.88 km (calculated)[4]
13.977±0.227 km[8]
14.767±0.219 km[9]
4.1025±0.0002 h[10]
4.10295±0.00005 h[11]
4.104±0.001 h[12]
4.3±0.3 h (poor)[13]
0.21 (assumed)[4]
0.2242±0.0366[9]
0.249±0.014[8]
0.291±0.312[6]
0.349±0.028[7]
S (assumed)[4]
11.10[7] · 11.16±0.38[14] · 11.4[9] · 11.43[6] · 11.6[1][4]

Orbit and classification

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Based on the Hierarchical Clustering Method, which uses a body's proper orbital elements, Illyria is a member of the Maria family (506),[5][11]: 18  a large intermediate belt family of stony asteroids.[16] It has also been grouped into the Eunomia family (502), an even larger family with more than 5,000 known members.[4]

Illyria orbits the Sun in the central asteroid belt at a distance of 2.3–2.9 AU once every 4 years and 1 month (1,497 days; semi-major axis of 2.56 AU). Its orbit has an eccentricity of 0.12 and an inclination of 15° with respect to the ecliptic.[1] The body's observation arc begins with a recovery observation at Lowell Observatory in October 1929, three weeks after its official discovery observation at Heidelberg.[15]

Physical characteristics

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Illyria is an assumed stony S-type asteroid,[4] which agrees with the overall spectral type of both the Maria and Eunomia family.[16]: 23 

Rotation period

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Several rotational lightcurves of Illyria have been obtained from photometric observations since 2007.[10][12][13] Lightcurve analysis gave a consolidated rotation period of 4.1025 hours with a brightness amplitude between 0.56 and 0.91 magnitude (U=3).[4][10]

Spin axis

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In 2013, an international study also modeled the asteroid's lightcurve from photometric data. It gave a concurring period of 4.10295 hours and determined a partial spin axis of (n.a., 47.0°) in ecliptic coordinates (λ, β).[11]

Diameter and albedo

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According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Illyria measures between 12.73 and 14.767 kilometers in diameter and its surface has an albedo between 0.2242 and 0.349.[6][7][8][9]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.21, derived from the parent body of the Eunomia family, and calculates a diameter of 13.88 kilometers based on an absolute magnitude of 11.6.[4]

Naming

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This minor planet was named after Illyria, an ancient region on the Balkans which borders the Adriatic Sea. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 108).[3]

References

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  1. ^ a b c d "JPL Small-Body Database Browser: 1160 Illyria (1929 RL)" (2017-06-04 last obs.). Jet Propulsion Laboratory. Retrieved 29 November 2017.
  2. ^ "Illyria". Merriam-Webster.com Dictionary. Merriam-Webster.
  3. ^ a b c Schmadel, Lutz D. (2007). "(1160) Illyria". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 98. doi:10.1007/978-3-540-29925-7_1161. ISBN 978-3-540-00238-3.
  4. ^ a b c d e f g h i "LCDB Data for (1160) Illyria". Asteroid Lightcurve Database (LCDB). Retrieved 29 November 2017.
  5. ^ a b "Asteroid 1160 Illyria – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
  6. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 29 November 2017.
  7. ^ a b c d 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)
  8. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121.
  9. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  10. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (1160) Illyria". Geneva Observatory. Retrieved 29 November 2017.
  11. ^ a b c Hanus, J.; Broz, M.; Durech, J.; Warner, B. D.; Brinsfield, J.; Durkee, R.; et al. (November 2013). "An anisotropic distribution of spin vectors in asteroid families". Astronomy and Astrophysics. 559: 19. arXiv:1309.4296. Bibcode:2013A&A...559A.134H. doi:10.1051/0004-6361/201321993.
  12. ^ a b Bennefeld, Craig; Bass, Stephen; Blair, Ricco; Cunningham, Kendrick; Hill, Da'quia; McHenry, Michael; et al. (October 2009). "Asteroid Lightcurve Analysis at Ricky Observatory". The Minor Planet Bulletin. 36 (4): 147–148. Bibcode:2009MPBu...36..147B. ISSN 1052-8091. Retrieved 29 November 2017.
  13. ^ a b Kim, M.-J.; Choi, Y.-J.; Moon, H.-K.; Byun, Y.-I.; Brosch, N.; Kaplan, M.; et al. (March 2014). "Rotational Properties of the Maria Asteroid Family". The Astronomical Journal. 147 (3): 15. arXiv:1311.5318. Bibcode:2014AJ....147...56K. doi:10.1088/0004-6256/147/3/56. Retrieved 29 November 2017.
  14. ^ 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. Retrieved 29 November 2017.
  15. ^ a b "1160 Illyria (1929 RL)". Minor Planet Center. Retrieved 29 November 2017.
  16. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
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