1244 Deira

1244 Deira (prov. designation: 1932 KE) is a dark background asteroid and slow rotator from the inner region of the asteroid belt. The X-type asteroid has an exceptionally long rotation period of 210.6 hours and measures approximately 31 kilometers (19 miles) in diameter. It was discovered on 25 May 1932, by English-born South African astronomer Cyril Jackson at the Union Observatory in Johannesburg,[4] who named it after Deira, an old kingdom near his birthplace, the market town of Ossett, located in West Yorkshire, England.[3]

1244 Deira
Modelled shape of Deira from its lightcurve
Discovery [1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date25 May 1932
Designations
(1244) Deira
Pronunciation/ˈdaɪərə/ or /ˈdɛərə/[2]
Named after
Deira, near the town of Ossett, England [3]
(alt. Celtic Kingdom of Deira)
1932 KE · 1930 YR
1984 YQ6 · A908 TD
A921 GC · A924 BH
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc109.13 yr (39,861 days)
Aphelion2.5731 AU
Perihelion2.1129 AU
2.3430 AU
Eccentricity0.0982
3.59 yr (1,310 days)
335.23°
0° 16m 29.28s / day
Inclination8.6950°
277.12°
261.45°
Physical characteristics
Mean diameter
28.816±0.546 km[7]
30.432±9.136 km[8]
30.95±1.9 km[9]
31.799±0.487 km[10]
32.28±0.35 km[11]
33.15±7.01 km[12]
35.19±0.19 km[13]
5 (poor) h[14]
210.6±0.1 h[lower-alpha 1]
216.98±0.05 h[15]
217.1±0.1 h[lower-alpha 2]
  • (314.0°, −46.0°) (λ1/β1)[6]
  • (107.0°, −56.0°) (λ2/β2)[6]
0.03±0.00[13]
0.0357±0.0051[10]
0.037±0.011[12]
0.0416±0.0312[8]
0.052±0.001[11]
0.0557±0.007[9]
11.30[9][10][11]
11.50[1][17][8]

    Orbit and classification

    Deira is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[5][6] It orbits the Sun in the inner asteroid belt at a distance of 2.1–2.6 AU once every 3 years and 7 months (1,310 days; semi-major axis 2.34 AU). Its orbit has an eccentricity of 0.10 and an inclination of 9° with respect to the ecliptic.[1] The body's observation arc begins with its first observations as A908 TD at Heidelberg Observatory in October 1908, or more than 23 years prior to its official discovery observation at Johannesburg.[4]

    Naming

    This minor planet was named by the discoverer Cyril Jackson after his birthplace, the market town of Ossett, located in West Yorkshire, England (also see 2193 Jackson).[3] The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 115).[3] While the naming citation reads that Deira is the ancient name for his birthplace, the Celtic Kingdom of Deira was actually much larger, encompassing at its height most of Yorkshire in Northern England.

    Physical characteristics

    Deira has been characterized as a primitive P-type asteroid by the space-based Wide-field Infrared Survey Explorer (WISE).[10] While P-type bodies are common in the outermost asteroid belt and among the Jupiter trojans, they are rarely found in the inner main belt. In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Deira is an X-type asteroid.[6][16]

    Rotation period

    In March 2011, a rotational lightcurve of Deira was obtained from photometric observations by Julian Oey at his Leura Observatory (E17) in Australia. Lightcurve analysis gave a rotation period of 210.6 hours with a brightness variation of 0.5 magnitude (U=2),[lower-alpha 1] while Oey previously published a slightly longer period of 217.1 hours and an amplitude of 0.6 magnitude (U=n.a.).[lower-alpha 2] This makes Deira one of the Top 300 slow rotators known to exist.

    Spin axis

    In 2016, an international study modeled a lightcurve with a concurring period of 216.98 hours and found two spin axis of (314.0°, −46.0°) and (107.0°, −56.0°) in ecliptic coordinates (λ, β).[15]

    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 WISE telescope, Deira measures between 28.816 and 35.19 kilometers in diameter and its surface has an albedo between 0.03 and 0.0557.[7][8][9][10][11][12][13]

    The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0465 and a diameter of 30.89 kilometers based on an absolute magnitude of 11.5.[17]

    Notes
    1. Oey (2011) LCDB. (1244) Deira – rotation period 210.6±0.1 hours with a brightness amplitude of 0.50±0.03 mag. Quality code of 2. Summary figures at the LCDB.
    2. Oey (2007) website. (1244) Deira – rotation period 217.1±0.1 hours with a brightness amplitude of 0.60±0.05 mag. No quality code. Lightcurve-plot and summary figures at the archived Leura Observatory website. Astronomers comment: "The data is re-reduced with Canopus 9.5 Comp Star Selector feature. Linkage over the 2.5 months period showing a main period of 217h. Slow rotator with deviation from the mean due to Psyn-sid and tumbling characteristics."

    References
    1. "JPL Small-Body Database Browser: 1244 Deira (1932 KE)" (2017-11-25 last obs.). Jet Propulsion Laboratory. Retrieved 3 January 2018.
    2. A Complete Pronouncing Gazetteer, Or, Geographical Dictionary of the World, 1880
    3. Schmadel, Lutz D. (2007). "(1244) Deira". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 103. doi:10.1007/978-3-540-29925-7_1245. ISBN 978-3-540-00238-3.
    4. "1244 Deira (1932 KE)". Minor Planet Center. Retrieved 3 January 2018.
    5. "Asteroid 1244 Deira – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
    6. "Asteroid 1244 Deira". Small Bodies Data Ferret. Retrieved 15 March 2020.
    7. Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 3 January 2018.
    8. Masiero, Joseph R.; Nugent, C.; Mainzer, A. K.; Wright, E. L.; Bauer, J. M.; Cutri, R. M.; et al. (October 2017). "NEOWISE Reactivation Mission Year Three: Asteroid Diameters and Albedos". The Astronomical Journal. 154 (4): 10. arXiv:1708.09504. Bibcode:2017AJ....154..168M. doi:10.3847/1538-3881/aa89ec.
    9. Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
    10. 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.
    11. 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. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
    12. Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 3 January 2018.
    13. Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 3 January 2018.
    14. Behrend, Raoul. "Asteroids and comets rotation curves – (1244) Deira". Geneva Observatory. Retrieved 3 January 2018.
    15. Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441.
    16. Lazzaro, D.; Angeli, C. A.; Carvano, J. M.; Mothé-Diniz, T.; Duffard, R.; Florczak, M. (November 2004). "S3OS2: the visible spectroscopic survey of 820 asteroids" (PDF). Icarus. 172 (1): 179–220. Bibcode:2004Icar..172..179L. doi:10.1016/j.icarus.2004.06.006. Retrieved 15 March 2020.
    17. "LCDB Data for (1244) Deira". Asteroid Lightcurve Database (LCDB). Retrieved 3 January 2018.
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