Astronomy:973 Aralia

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973 Aralia
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date18 March 1922
Designations
(973) Aralia
Pronunciation/əˈrliə/[6]
Named afterAralia[2]
(genus of plants)
A922 FB · 1954 SE
1922 LR
Minor planet categorymain-belt [1] · (outer)[3]
Ursula [4][5]
Orbital characteristics[3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc97.80 yr (35,720 d)
|{{{apsis}}}|helion}}3.5717 AU
|{{{apsis}}}|helion}}2.8522 AU
3.2119 AU
Eccentricity0.1120
Orbital period5.76 yr (2,103 d)
Mean anomaly63.633°
Mean motion0° 10m 16.32s / day
Inclination15.828°
Longitude of ascending node348.44°
87.856°
Physical characteristics
Mean diameter
  • 51.60±1.6 km[7]
  • 51.609±0.389 km[8]
  • 55.50±0.77 km[9]
Rotation period7.3662±0.0003 h
Geometric albedo
  • 0.084±0.003[9]
  • 0.0959±0.006[7]
  • 0.098±0.018[8]
Absolute magnitude (H)10.1[1][3]


973 Aralia (prov. designation: A922 FB or 1922 LR) is an asteroid of the Ursula family located in the outer regions of the asteroid belt, approximately 52 kilometers (32 miles) in diameter. It was discovered on 18 March 1922, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany.[1] The Xk-type asteroid has a rotation period of 7.3 hours. It was named after the genus of ivy-like plant Aralia, also known as "spikenard".[2]

Orbit and classification

Aralia is a core member of the Ursula family (631), a large family of C- and X-type asteroids, named after 375 Ursula.[5][4][11]:23 It orbits the Sun in the outer main-belt at a distance of 2.9–3.6 AU once every 5 years and 9 months (2,103 days; semi-major axis of 3.21 AU). Its orbit has an eccentricity of 0.11 and an inclination of 16° with respect to the ecliptic.[3] The body's observation arc begins at Vienna Observatory on 28 March 1922, or 10 days after its official discovery observation at Heidelberg.[1]

Naming

This minor planet was named after the genus of the Eurasian ivy-like plant Aralia, also known as "spikenard". A member of the Ginseng family, it has evergreen leaves, small yellowish flowers, and black berries. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 93).[2]

Physical characteristics

In the SMASS classification, Aralia is a Xk-type, a transitional subtype of the X-type to the less common K-type asteroids.[3] In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), it is an X-type asteroid.[4][10] The overall spectral type of the Ursula family is that of a C and X-type.[11]:23

Rotation period

In May 2015, a rotational lightcurve of Aralia was obtained from photometric observations by Julian Oey, Hasen Williams and Roger Groom at the Blue Mountains Observatory (Q68) and Darling Range Observatory (DRO). Lightcurve analysis gave a rotation period of 7.3662±0.0003 hours with a brightness variation of 0.23±0.02 magnitude ({{{1}}}).[12] Alternative observations by Robert Stephens at the Santana Observatory (646) in 2001 and Michael S. Alkema at the Elephant Head Observatory (G35) in 2012, gave a similar period determination of 7.29±0.01 and 7.291±0.003 hours, with an amplitude of 0.25±0.03 and 0.20±0.02, respectively ({{{1}}}).[13]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Japanese Akari satellite, Aralia measures between 51.6 and 55.5 kilometers in diameter and its surface an albedo between 0.08 and 0.10.[7][8][9] Additional publications by WISE in 2012 and 2015, gave a mean-diameter 56.403±5.687 and 46.724±16.447, with an albedo of 0.069±0.402 and 0.073±0.041, respectively.[4][13] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0614 and a diameter of 51.24 kilometers based on an absolute magnitude of 10.1.[13]

References

  1. 1.0 1.1 1.2 1.3 1.4 "973 Aralia (A922 FB)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=973. 
  2. 2.0 2.1 2.2 Schmadel, Lutz D. (2007). "(973) Aralia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 85. doi:10.1007/978-3-540-29925-7_974. ISBN 978-3-540-00238-3. https://archive.org/details/dictionaryminorp00schm. 
  3. 3.0 3.1 3.2 3.3 3.4 3.5 "JPL Small-Body Database Browser: 973 Aralia (A922 FB)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000973. 
  4. 4.0 4.1 4.2 4.3 "Asteroid 973 Aralia". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=973+Aralia. 
  5. 5.0 5.1 "Asteroid 973 Aralia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=973. 
  6. "aralia". aralia. Oxford University Press. http://www.lexico.com/definition/aralia. 
  7. 7.0 7.1 7.2 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. Bibcode2004PDSS...12.....T. https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab. Retrieved 10 February 2020. 
  8. 8.0 8.1 8.2 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. doi:10.1088/0004-637X/791/2/121. Bibcode2014ApJ...791..121M. 
  9. 9.0 9.1 9.2 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. doi:10.1093/pasj/63.5.1117. Bibcode2011PASJ...63.1117U.  (online, AcuA catalog p. 153)
  10. 10.0 10.1 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". Icarus 172 (1): 179–220. doi:10.1016/j.icarus.2004.06.006. Bibcode2004Icar..172..179L. http://sirrah.troja.mff.cuni.cz/yarko-site/tmp/eos/NEW/spectral_type_figure/s3os2.pdf. Retrieved 10 February 2020. 
  11. 11.0 11.1 Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131. Bibcode2015aste.book..297N. 
  12. Oey, Julian; Williams, Hasen; Groom, Roger (July 2017). "Lightcurve Analysis of Asteroids from BMO and DRO in 2015". Minor Planet Bulletin 44 (3): 200–204. ISSN 1052-8091. Bibcode2017MPBu...44..200O. http://www.minorplanet.info/MPB/issues/MPB_44-3.pdf. Retrieved 23 February 2020. 
  13. 13.0 13.1 13.2 "LCDB Data for (973) Aralia". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=973. 

External links