{{Short description|Main-belt asteroid}} {{Use dmy dates|date=March 2018}} {{Infobox planet | minorplanet = yes | name = 1020 Arcadia | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="MPC-object" /> | discoverer = K. Reinmuth | discovery_site = Heidelberg Obs. | discovered = 7 March 1924 | mpc_name = (1020) Arcadia | alt_names = 1924 QV{{·}}{{mp|1954 UA|2}}<br />1975 EQ{{·}}{{mp|1977 QO|2}} | pronounced = {{IPAc-en|ɑr|ˈ|k|eɪ|d|i|ə}}<ref>{{OED|Arcadian}}</ref> | named_after = {{nowrap|Arcadia {{small|(Greek region)}}<ref name="springer" />}} | mp_category = main-belt<ref name="MPC-object" /><ref name="jpldata" />{{·}}{{small|(middle)}}<br />Agnia<ref name="Ferret" /><ref name="Sunshine-2004" /> | orbit_ref = <ref name="jpldata" /> | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 93.89 yr (34,293 d) | aphelion = 2.9152 AU | perihelion = 2.6666 AU | semimajor = 2.7909 AU | eccentricity = 0.0445 | period = 4.66 yr (1,703 d) | mean_anomaly = 18.189° | mean_motion = {{Deg2DMS|0.2114|sup=ms}} / day | inclination = 4.0598° | asc_node = 180.71° | arg_peri = 37.691° | mean_diameter = {{val|10.067|0.090|ul=km}}<ref name="Masiero-2011" /><br />{{val|10.415|0.123|u=km}}<ref name="WISE" /><br />{{val|13.02|0.49|u=km}}<ref name="Masiero-2012" /><br />{{val|21.16|u=km}} {{small|(calculated)}}<ref name="lcdb" /> | rotation = {{val|17.02|0.02|ul=h}}<ref name="Gartrelle-2012" /> | albedo = 0.057 {{small|(assumed)}}<ref name="lcdb" /><br />{{val|0.150|0.023}}<ref name="Masiero-2012" /><br />{{val|0.2364|0.0456}}<ref name="WISE" /> | spectral_type = SMASS {{=}} S<ref name="jpldata" />{{·}}S<ref name="Veres-2015" /><br />S{{small|(SDSS-MFB)}}<ref name="lcdb" /> | abs_magnitude = 12.0<ref name="jpldata" />{{·}}12.10<ref name="WISE" /><ref name="Masiero-2012" /><ref name="lcdb" /><br />{{val|12.29|0.11}}<ref name="Veres-2015" /> }}
'''1020 Arcadia''', provisional designation {{mp|1924 QV}}, is a stony Agnia asteroid from the central regions of the asteroid belt, approximately {{convert|11|km|mi|abbr=off|sigfig=1|sp=us}} in diameter. It was discovered on 7 March 1924, by German astronomer Karl Reinmuth at the Heidelberg Observatory in Heidelberg, Germany.<ref name="MPC-object" /> The asteroid was named after the Greek region of Arcadia.<ref name="springer" />
== Orbit and classification ==
''Arcadia'' is a member of the Agnia family ({{small|514}}),<ref name="Ferret" /><ref name="Sunshine-2004" /> a very large family of stony asteroids with more than 2000 known members.<ref name="Nesvorny-2014" /> They most likely formed from the breakup of a basalt object, which in turn was spawned from a larger parent body that underwent igneous differentiation.<ref name="Sunshine-2004" /> The family's parent body and namesake is the asteroid 847 Agnia.<ref name="Nesvorny-2014" />
It orbits the Sun in the central main-belt at a distance of 2.7–2.9 AU once every 4 years and 8 months (1,703 days; semi-major axis of 2.79 AU). Its orbit has an eccentricity of 0.04 and an inclination of 4° with respect to the ecliptic.<ref name="jpldata" /> The body's observation arc begins at Heidelberg in March 1924, six days after its official discovery observation.<ref name="MPC-object" />
== Physical characteristics ==
In the SMASS classification, ''Arcadia'' is a common, stony S-type asteroid.<ref name="jpldata" /> It has been characterized as an S-type by Pan-STARRS photometric survey,<ref name="Veres-2015" /> as well as by SDSS-MFB (Masi Foglia Bus).<ref name="lcdb" />
=== Rotation period ===
In November 2011, a fragmentary rotational lightcurve of ''Arcadia'' was obtained from photometric observations by Gordon Gartrelle at the University of North Dakota. Lightcurve analysis gave a rotation period of 17.02 hours with a brightness amplitude of 0.05 magnitude ({{small|U=1}}).<ref name="Gartrelle-2012" /> As of 2018, no secure period has been obtained.<ref name="lcdb" />
=== Diameter and albedo ===
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Arcadia'' measures between 10.067 and 13.02 kilometers in diameter and its surface has an albedo between 0.150 and 0.2364.<ref name="Masiero-2011" /><ref name="WISE" /><ref name="Masiero-2012" /> The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo 0.057, i.e. an albedo for a carbonaceous rather than for a stony asteroid, and consequently calculates a much larger diameter of 21.16 kilometers based on an absolute magnitude of 12.1.<ref name="lcdb" /> It may be speculated whether this anomaly is a glitch in the data base.
== Naming ==
This minor planet was named after the Greek region of Arcadia in central Peloponnese. It is also a celebrated mythological region, where the shepherd god Pan lived. The official naming citation was mentioned in ''The Names of the Minor Planets'' by Paul Herget in 1955 ({{small|H 97}}).<ref name="springer" />
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2018-01-27 last obs. |title = JPL Small-Body Database Browser: 1020 Arcadia (1924 QV) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001020 |publisher = Jet Propulsion Laboratory |access-date = 8 March 2018}}</ref>
<ref name="springer">{{cite book |last = Schmadel | first = Lutz D. |title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg |page = 88 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1021 |chapter = (1020) Arcadia }}</ref>
<ref name="MPC-object">{{cite web |title = 1020 Arcadia (1924 QV) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1020 |access-date = 8 March 2018}}</ref>
<ref name="Masiero-2011">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = A. K. |last2 = Mainzer |first3 = T. |last3 = Grav |first4 = J. M. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = J. |last6 = Dailey |first7 = P. R. M. |last7 = Eisenhardt |first8 = R. S. |last8 = McMillan |first9 = T. B. |last9 = Spahr |first10 = M. F. |last10 = Skrutskie |first11 = D. |last11 = Tholen |first12 = R. G. |last12 = Walker |first13 = E. L. |last13 = Wright |first14 = E. |last14 = DeBaun |first15 = D. |last15 = Elsbury |first16 = T. IV |last16 = Gautier |first17 = S. |last17 = Gomillion |first18 = A. |last18 = Wilkins |date = November 2011 |title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M |journal = The Astrophysical Journal |volume = 741 |issue = 2 |page = 20 |bibcode = 2011ApJ...741...68M |doi = 10.1088/0004-637X/741/2/68 |arxiv = 1109.4096 |access-date= 8 March 2018}}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 1020 Arcadia – Nesvorny HCM Asteroid Families V3.0 |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1020+Arcadia |access-date = 24 October 2019}}</ref>
<ref name="Nesvorny-2014">{{Cite book |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 = 978-0-8165-3213-1}}</ref>
<ref name="Sunshine-2004">{{Cite journal |first1 = Jessica M. |last1 = Sunshine |first2 = Schelte J. |last2 = Bus |first3 = Timothy J. |last3 = McCoy |first4 = Thomas H. |last4 = Burbine |first5 = Catherine M. |last5 = Corrigan |first6 = Richard P. |last6 = Binzel |date = August 2004 |title = High-calcium pyroxene as an indicator of igneous differentiation in asteroids and meteorites |url = https://www.researchgate.net/publication/228936637 |journal = Meteoritics and Planetary Science |volume = 39 |issue = 8 |pages = 1343–1357 |bibcode = 2004M&PS...39.1343S |doi = 10.1111/j.1945-5100.2004.tb00950.x |access-date= 8 March 2018|doi-access= }}</ref>
<ref name="lcdb">{{cite LCDB|number = 1020 |access-date = 8 March 2018}}</ref>
<ref name="Masiero-2012">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = A. K. |last2 = Mainzer |first3 = T. |last3 = Grav |first4 = J. M. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = C. |last6 = Nugent |first7 = M. S. |last7 = Cabrera |date = November 2012 |title = Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759L...8M |journal = The Astrophysical Journal Letters |volume = 759 |issue = 1 |page = 5 |bibcode = 2012ApJ...759L...8M |doi = 10.1088/2041-8205/759/1/L8 |arxiv = 1209.5794 |access-date= 8 March 2018}}</ref>
<ref name="WISE">{{cite journal |display-authors = 6 |first1 = A. |last1 = Mainzer |first2 = T. |last2 = Grav |first3 = J. |last3 = Masiero |first4 = E. |last4 = Hand |first5 = J. |last5 = Bauer |first6 = D. |last6 = Tholen |first7 = R. S. |last7 = McMillan |first8 = T. |last8 = Spahr |first9 = R. M. |last9 = Cutri |first10 = E. |last10 = Wright |first11 = J. |last11 = Watkins |first12 = W. |last12 = Mo |first13 = C. |last13 = Maleszewski |date = November 2011 |title = NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results |journal = The Astrophysical Journal |volume = 741 |issue = 2 |page = 25 |bibcode = 2011ApJ...741...90M |doi = 10.1088/0004-637X/741/2/90 |arxiv = 1109.6407}}</ref>
<ref name="Gartrelle-2012">{{Cite journal |author = Gartrelle, Gordon M. |date = April 2012 |title = Lightcurve Results for Eleven Asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012MPBu...39...40G |journal = The Minor Planet Bulletin |volume = 39 |issue = 2 |pages = 40–46 |issn = 1052-8091 |bibcode = 2012MPBu...39...40G |access-date= 8 March 2018}}</ref>
<ref name="Veres-2015">{{cite journal |display-authors = 6 |first1 = Peter |last1 = Veres |first2 = Robert |last2 = Jedicke |first3 = Alan |last3 = Fitzsimmons |first4 = Larry |last4 = Denneau |first5 = Mikael |last5 = Granvik |first6 = Bryce |last6 = Bolin |first7 = Serge |last7 = Chastel |first8 = Richard J. |last8 = Wainscoat |first9 = William S. |last9 = Burgett |first10 = Kenneth C. |last10 = Chambers |first11 = Heather |last11 = Flewelling |first12 = Nick |last12 = Kaiser |first13 = Eugen A. |last13 = Magnier |first14 = Jeff S. |last14 = Morgan |first15 = Paul A. |last15 = Price |first16 = John L. |last16 = Tonry |first17 = Christopher |last17 = Waters |date = November 2015 |title = Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V |journal = Icarus |volume = 261 |pages = 34–47 |bibcode = 2015Icar..261...34V |doi = 10.1016/j.icarus.2015.08.007 |arxiv = 1506.00762 |access-date= 8 March 2018}}</ref>
}} <!-- end of reflist -->
== External links == * [http://www.minorplanet.info/PHP/lcdbsummaryquery.php Asteroid Lightcurve Database (LCDB)], query form ([http://www.minorplanet.info/lightcurvedatabase.html info] {{Webarchive|url=https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html |date=16 December 2017 }}) * [https://books.google.com/books?id=aeAg1X7afOoC&pg Dictionary of Minor Planet Names], Google books * [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1020}} * {{JPL small body}}
{{Minor planets navigator |1019 Strackea |number=1020 |1021 Flammario}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Arcadia}} 001020 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 001020 19240307