{{Short description|Main-belt asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1187 Afra | background = #D6D6D6 | image = 001187-asteroid shape model (1187) Afra.png | image_scale = | caption = Modelled shape of ''Afra'' from its lightcurve | discovery_ref = <ref name="MPC-object" /> | discovered = 6 December 1929 | discoverer = K. Reinmuth | discovery_site = Heidelberg Obs. | mpc_name = (1187) Afra | alt_names = 1929 XC | named_after = unknown<ref name="springer" /> | mp_category = {{plainlist| * {{nowrap|main-belt<ref name="MPC-object" /><ref name="jpldata" />{{·}}{{small|(middle)}}}} * background<ref name="AstDys-object" /><ref name="Ferret" />}} | orbit_ref = <ref name="jpldata" /> | epoch = 31 May 2020 (JD 2459000.5) | uncertainty = 0 | observation_arc = 90.16 yr (32,932 d) | aphelion = 3.2285 AU | perihelion = 2.0523 AU | semimajor = 2.6404 AU | eccentricity = 0.2227 | period = 4.29 yr (1,567 d) | mean_anomaly = 52.040° | mean_motion = {{Deg2DMS|0.2297|sup=ms}} / day | inclination = 10.697° | asc_node = 327.16° | arg_peri = 74.956° | mean_diameter = {{plainlist| * {{val|31.83|3.9|ul=km}}<ref name="SIMPS" /> * {{val|31.96|0.33|u=km}}<ref name="AKARI" /> * {{val|32.348|0.299|u=km}}<ref name="Mainzer-2016" />}} | rotation = {{plainlist| * {{val|14.06993|0.00001|ul=h}}<ref name="Durech-2016" /> * {{val|14.0701|0.0005|u=h}}<ref name="geneva-obs" /> * {{val|14.09|0.02|u=h}}<ref name="Menke-2008a" /> * {{val|14.645|0.006|u=h}}<ref name="Clark-2019" />}} | albedo = {{plainlist| * {{val|0.051|0.007}}<ref name="Mainzer-2016" /> * {{val|0.0527}}<ref name="SIMPS" /> * {{val|0.053}}<ref name="AKARI" />}} | spectral_type = SMASS {{=}} X<ref name="jpldata" /> | abs_magnitude = 11.50<ref name="MPC-object" /><ref name="jpldata" /> }}
'''1187 Afra''' (''prov. designation'': {{mp|1929 XC}}) is a dark background asteroid from the central regions of the asteroid belt. It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory on 6 December 1929.<ref name="MPC-object" /> The X-type asteroid has a rotation period of 14.1 hours and measures approximately {{convert|32|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. The origin of the asteroid's name remains unknown.
== Orbit and classification ==
''Afra'' is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.<ref name="AstDys-object" /><ref name="Ferret" /> It orbits the Sun in the central asteroid belt at a distance of 2.1–3.2 AU once every 4 years and 3 months (1,567 days; semi-major axis of 2.64 AU). Its orbit has an eccentricity of 0.22 and an inclination of 11° with respect to the ecliptic.<ref name="jpldata" /> The body's observation arc begins at Heidelberg in January 1930, seven weeks after its official discovery observation.<ref name="MPC-object" />
== Naming ==
It is not known to what person, group of persons, or occurrence the name "Afra" refers to.<ref name="springer" />
=== Unknown meaning ===
Among the many thousands of named minor planets, ''Afra'' is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between {{mp|{{MoMP|164|164 Eva}}}} and {{mp|{{MoMP|1514|1514 Ricouxa}}}} and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois, Johann Palisa, Max Wolf and Karl Reinmuth.<ref name="DOMPN-unknown" />
== Physical characteristics ==
The lightcurve of ''Afra'' shows a periodicity of {{val|14.09|0.02}} hours, during which time the brightness of the object varies by {{val|0.40|0.02}} in magnitude.<ref name="Menke-2008a" /><ref name="lcdb" />
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2020-02-04 last obs. |title = JPL Small-Body Database Browser: 1187 Afra (1929 XC) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001187 |archive-url = https://web.archive.org/web/20200918035857/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001187 |url-status = dead |archive-date = 18 September 2020 |publisher = Jet Propulsion Laboratory |accessdate = 14 March 2020}}</ref>
<ref name="springer">{{cite book |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 = (1187) Afra |page = [https://archive.org/details/dictionaryminorp00schm/page/n113 100] |date = 2007 |doi = 10.1007/978-3-540-29925-7_1188 |isbn = 978-3-540-00238-3}}</ref>
<ref name="DOMPN-unknown">{{cite book |title = Dictionary of Minor Planet Names – Fifth Revised and Enlarged revision |chapter = Appendix 11 – Minor Planet Names with Unknown Meaning |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |pages = 927–929 |date = 2007 |isbn = 978-3-540-00238-3 |author-link= Lutz D. Schmadel}}</ref>
<ref name="MPC-object">{{cite web |title = 1187 Afra (1929 XC) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1187 |accessdate = 14 March 2020}}</ref>
<ref name="geneva-obs">{{cite web |title = Asteroids and comets rotation curves – (1187) Afra |last = Behrend |first = Raoul |publisher = Geneva Observatory |url = http://obswww.unige.ch/~behrend/page3cou.html#001187 |accessdate = 14 March 2020}}</ref>
<ref name="SIMPS">{{cite journal |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 |accessdate = 14 March 2020}}</ref>
<ref name="AKARI">{{cite journal |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= }} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=1187 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])</ref>
<ref name="Mainzer-2016">{{cite journal |display-authors = 6 |first1 = A. K. |last1 = Mainzer |first2 = J. M. |last2 = Bauer |first3 = R. M. |last3 = Cutri |first4 = T. |last4 = Grav |first5 = E. A. |last5 = Kramer |first6 = J. R. |last6 = Masiero |first7 = C. R. |last7 = Nugent |first8 = S. M. |last8 = Sonnett |first9 = R. A. |last9 = Stevenson |first10 = E. L. |last10 = Wright |date = June 2016 |title = NEOWISE Diameters and Albedos V1.0 |url = https://sbnarchive.psi.edu/pds3/non_mission/EAR_A_COMPIL_5_NEOWISEDIAM_V1_0/data/neowise_mainbelt.tab |journal = NASA Planetary Data System |bibcode = 2016PDSS..247.....M |access-date= 14 March 2020}}</ref>
<ref name="lcdb">{{cite LCDB|number = 1187 |accessdate = 14 March 2020}}</ref>
<ref name="Menke-2008a">{{cite journal |last1 = Menke |first1 = John |last2 = Cooney |first2 = Walt |last3 = Gross |first3 = John |last4 = Terrell |first4 = Dirk |last5 = Higgins |first5 = David |date = October 2008 |title = Asteroid Lightcurve Analysis at Menke Observatory |journal = Minor Planet Bulletin |url = http://www.minorplanet.info/MPB/issues/MPB_35-4.pdf |volume = 35 |issue = 4 |pages = 155–160 |bibcode = 2008MPBu...35..155M |issn = 1052-8091}}</ref>
<ref name="Durech-2016">{{cite journal |last1 = Ďurech |first1 = J. |last2 = Hanuš |first2 = J. |last3 = Oszkiewicz |first3 = D. |last4 = Vančo |first4 = R. |date = March 2016 |title = Asteroid models from the Lowell photometric database |journal = Astronomy and Astrophysics |volume = 587 |page = A48 |bibcode = 2016A&A...587A..48D |issn = 0004-6361 |doi = 10.1051/0004-6361/201527573 |arxiv = 1601.02909}}</ref>
<ref name="Clark-2019">{{cite journal |last1 = Clark |first1 = Maurice |date = July 2019 |title = Asteroid Photometry from the Preston Gott Observatory |journal = Minor Planet Bulletin |url = http://www.minorplanet.info/MPB/issues/MPB_46-3.pdf |volume = 46 |issue = 3 |pages = 346–349 |bibcode = 2019MPBu...46..346C |issn = 1052-8091}}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 1187 Afra |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1187+Afra |accessdate = 14 March 2020}}</ref>
<ref name="AstDys-object">{{cite web |title = Asteroid 1187 Afra – Proper Elements |publisher = AstDyS-2, Asteroids – Dynamic Site |url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1187 |access-date= 14 March 2020}}</ref>
}} <!-- end of reflist -->
== 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://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – ''Geneva Observatory'', Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1187}} * {{JPL small body}}
{{Minor planets navigator |1186 Turnera |number=1187 |1188 Gothlandia}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Afra}} 001187 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 001187 19291206