973 Aralia
{{Short description|Asteroid of the Ursula family}}
{{Use dmy dates|date=February 2020}}
{{Infobox planet
| minorplanet = yes
| name = 973 Aralia
| background = #D6D6D6
| image =
| image_size =
| caption =
| discoverer = K. Reinmuth
| discovery_site = Heidelberg Obs.
| discovered = 18 March 1922
| mpc_name = (973) Aralia
| alt_names = A922 FB{{·}}1954 SE
1922 LR
| pronounced = {{IPAc-en|ə|'|r|eɪ|l|i|ə}}{{Cite encyclopedia |url=http://www.lexico.com/definition/aralia |archive-url=https://web.archive.org/web/20200322185904/https://www.lexico.com/definition/aralia |url-status=dead |archive-date=22 March 2020 |title=aralia |dictionary=Lexico UK English Dictionary |publisher=Oxford University Press}}
| named_after = Aralia
{{small|(genus of plants)}}
| mp_category = main-belt{{·}}{{small|(outer)}}
Ursula
| epoch = 31 May 2020 (JD 2459000.5)
| uncertainty = 0
| observation_arc = 97.80 yr (35,720 d)
| aphelion = 3.5717 AU
| perihelion = 2.8522 AU
| semimajor = 3.2119 AU
| eccentricity = 0.1120
| period = 5.76 yr (2,103 d)
| mean_anomaly = 63.633°
| mean_motion = {{Deg2DMS|0.1712|sup=ms}} / day
| inclination = 15.828°
| asc_node = 348.44°
| arg_peri = 87.856°
| mean_diameter = {{plainlist|
| rotation = {{val|7.3662|0.0003|ul=h}}
| albedo = {{plainlist|
| spectral_type = {{plainlist|
}}
973 Aralia (prov. designation: {{mp|A922 FB}} or {{mp|1922 LR}}) is an asteroid of the Ursula family located in the outer regions of the asteroid belt, approximately {{convert|52|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 18 March 1922, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southern Germany. 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".
Orbit and classification
Aralia is a core member of the Ursula family ({{small|631}}), a large family of C- and X-type asteroids, named after 375 Ursula.{{rp|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. The body's observation arc begins at Vienna Observatory on 28 March 1922, or 10 days after its official discovery observation at Heidelberg.
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 {{MoMP|973|naming was mentioned}} in The Names of the Minor Planets by Paul Herget in 1955 ({{small|H 93}}).
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. In both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), it is an X-type asteroid. The overall spectral type of the Ursula family is that of a C and X-type.{{rp|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 {{Obscode|Q68}} and Darling Range Observatory (DRO). Lightcurve analysis gave a rotation period of {{val|7.3662|0.0003}} hours with a brightness variation of {{val|0.23|0.02}} magnitude ({{small|U=3}}). Alternative observations by Robert Stephens at the Santana Observatory {{Obscode|646}} in 2001 and Michael S. Alkema at the Elephant Head Observatory {{Obscode|G35}} in 2012, gave a similar period determination of {{val|7.29|0.01}} and {{val|7.291|0.003}} hours, with an amplitude of {{val|0.25|0.03}} and {{val|0.20|0.02}}, respectively ({{small|U=2/2+}}).
= 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. Additional publications by WISE in 2012 and 2015, gave a mean diameter {{val|56.403|5.687}} and {{val|46.724|16.447}}, with an albedo of {{val|0.069|0.402}} and {{val|0.073|0.041}}, respectively. 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.
References
{{reflist|30em|refs=
|type = 2020-01-03 last obs.
|title = JPL Small-Body Database Browser: 973 Aralia (A922 FB)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2000973
|publisher = Jet Propulsion Laboratory
|access-date = 10 February 2020}}
|title = Dictionary of Minor Planet Names
|url = https://archive.org/details/dictionaryminorp00schm
|url-access = limited
|last = Schmadel | first = Lutz D.
|publisher = Springer Berlin Heidelberg
|chapter = (973) Aralia
|page = [https://archive.org/details/dictionaryminorp00schm/page/n98 85]
|date = 2007
|doi = 10.1007/978-3-540-29925-7_974
|isbn = 978-3-540-00238-3}}
|title = 973 Aralia (A922 FB)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=973
|access-date = 10 February 2020}}
|display-authors = 6
|first1 = Joseph R. |last1 = Masiero
|first2 = T. |last2 = Grav
|first3 = A. K. |last3 = Mainzer
|first4 = C. R. |last4 = Nugent
|first5 = J. M. |last5 = Bauer
|first6 = R. |last6 = Stevenson
|first7 = S. |last7 = Sonnett
|date = August 2014
|title = Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos
|journal = The Astrophysical Journal
|volume = 791
|issue = 2
|page = 11
|bibcode = 2014ApJ...791..121M
|doi = 10.1088/0004-637X/791/2/121
|arxiv = 1406.6645
}}
|title = LCDB Data for (973) Aralia
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=973
|access-date = 10 February 2020}}
|display-authors = 6
|first1 = Fumihiko |last1 = Usui
|first2 = Daisuke |last2 = Kuroda
|first3 = Thomas G. |last3 = Müller
|first4 = Sunao |last4 = Hasegawa
|first5 = Masateru |last5 = Ishiguro
|first6 = Takafumi |last6 = Ootsubo
|first7 = Daisuke |last7 = Ishihara
|first8 = Hirokazu |last8 = Kataza
|first9 = Satoshi |last9 = Takita
|first10 = Shinki |last10 = Oyabu
|first11 = Munetaka |last11 = Ueno
|first12 = Hideo |last12 = Matsuhara
|first13 = Takashi |last13 = Onaka
|date = October 2011
|title = Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey
|journal = Publications of the Astronomical Society of Japan
|volume = 63
|issue = 5
|pages = 1117–1138
|bibcode = 2011PASJ...63.1117U
|doi = 10.1093/pasj/63.5.1117
|doi-access= free
}} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=973 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])
|first1 = E. F. |last1 = Tedesco
|first2 = P. V. |last2 = Noah
|first3 = M. |last3 = Noah
|first4 = S. D. |last4 = Price
|date = October 2004
|title = IRAS Minor Planet Survey V6.0
|url = https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab
|journal = NASA Planetary Data System
|volume = 12
|pages = IRAS-A-FPA-3-RDR-IMPS-V6.0
|bibcode = 2004PDSS...12.....T
|access-date = 10 February 2020}}
|title = Asteroid 973 Aralia
|work = Small Bodies Data Ferret
|url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=973+Aralia
|access-date = 10 February 2020}}
|title = Asteroid 973 Aralia – Proper Elements
|publisher = AstDyS-2, Asteroids – Dynamic Site
|url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=973
|access-date= 10 February 2020}}
|first1 = D. |last1 = Nesvorný
|first2 = M. |last2 = Broz
|first3 = V. |last3 = Carruba
|date = December 2014
|chapter = Identification and Dynamical Properties of Asteroid Families
|title = Asteroids IV
|pages = 297–321
|bibcode = 2015aste.book..297N
|doi = 10.2458/azu_uapress_9780816532131-ch016
|arxiv = 1502.01628
|isbn = 9780816532131
}}
|first1 = D. |last1 = Lazzaro
|first2 = C. A. |last2 = Angeli
|first3 = J. M. |last3 = Carvano
|first4 = T. |last4 = Mothé-Diniz
|first5 = R. |last5 = Duffard
|first6 = M. |last6 = Florczak
|date = November 2004
|title = S3OS2: the visible spectroscopic survey of 820 asteroids
|url = http://sirrah.troja.mff.cuni.cz/yarko-site/tmp/eos/NEW/spectral_type_figure/s3os2.pdf
|journal = Icarus
|volume = 172
|issue = 1
|pages = 179–220
|bibcode = 2004Icar..172..179L
|doi = 10.1016/j.icarus.2004.06.006
|access-date= 10 February 2020}}
}}
External links
- [http://www.minorplanet.info/PHP/OneAsteroidInfo.php Lightcurve Database Query] (LCDB), at www.minorplanet.info
- [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books
- [http://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- {{AstDys|973}}
- {{JPL small body}}
{{Minor planets navigator |972 Cohnia |number=973 |974 Lioba}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Aralia}}