{{Short description|Main-belt asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 8661 Ratzinger | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="jpldata" /> | discovered = 14 October 1990 | discoverer = L. D. Schmadel<br />F. Börngen | discovery_site = {{nowrap|Karl Schwarzschild Obs.}} | mpc_name = (8661) Ratzinger | alt_names = {{mp|1990 TA|13}}{{·}}1969 US<br />{{mp|1974 TM|1}}{{·}}{{mp|1992 CB|1}} | named_after = Pope Benedict XVI<br />{{small|(Pope, chronology)}}<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(outer)}}<br />Eos<ref name="Ferret" /> | orbit_ref = <ref name="jpldata" /> | epoch = 31 May 2020 (JD 2459000.5) | uncertainty = 0 | observation_arc = 49.86 yr (18,213 days) | aphelion = 3.1158 AU | perihelion = 2.9001 AU | semimajor = 3.0080 AU | eccentricity = 0.0359 | period = 5.22 yr (1,906 days) | mean_anomaly = 176.919° | mean_motion = {{Deg2DMS|0.1889|sup=ms}} / day | inclination = 10.556° | asc_node = 38.061° | arg_peri = 90.968° | dimensions = {{val|13.394|0.198}}<ref name="Masiero-2011" /> | rotation = {{val|4.301035|0.000002|ul=h}}<ref name="Durech2018"/> | albedo = {{val|0.090|0.011}}<ref name="Masiero-2011" /> | spectral_type = S<ref name="lcdb" /> | abs_magnitude = 12.3<ref name="jpldata" /> }} {{Pope Benedict XVI sidebar}} '''8661 Ratzinger''', provisional designation {{mp|1990 TA|13}}, is an Eoan asteroid from the outer region of the asteroid belt, approximately 13.4 kilometers in diameter. It was discovered on 14 October 1990, by German astronomers Lutz Schmadel and Freimut Börngen at the Karl Schwarzschild Observatory in Tautenburg, eastern Germany.<ref name="MPC-Ratzinger" /> The asteroid was named after Cardinal Joseph Ratzinger, who became Pope Benedict XVI.<ref name="springer" />
== Orbit and classification ==
''Ratzinger'' is a member of the Eos family ({{small|606}}),<ref name="Ferret" /> the largest asteroid family in the outer main belt consisting of nearly 10,000 asteroids.<ref name="Nesvorny-2014" />{{rp|23}} It orbits the Sun at a distance of 2.9–3.1 AU once every 5 years and 3 months (1,906 days). Its orbit has an eccentricity of 0.04 and an inclination of 11° with respect to the ecliptic.<ref name="jpldata" />
In October 1969, it was first identified as {{mp|1969 US}} at Crimea–Nauchnij. The body's observation arc begins at Leoncito in 1974, when it was identified as {{mp|1974 TM|1}}, 16 years prior to its official discovery observation at Tautenburg.<ref name="MPC-Ratzinger" />
== Physical characteristics ==
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ''Ratzinger'' measures 13.4 kilometers in diameter and its surface has an albedo of 0.09.<ref name="Masiero-2011" /> In 2018, Josef Ďurech ''et al.'' measured its rotation period as {{val|4.301035|0.000002}} hours and provided a partial shape model.<ref name="Durech2018"/>
As of 2020, ''Ratzinger''{{'}}s composition remains unknown.<ref name="jpldata" /><ref name="lcdb" />
== Naming ==
This minor planet was named after German Joseph Ratzinger (born 1927), then Cardinal and professor of theology, for the role he played in supervising the opening of the Vatican Secret Archives in 1998 to researchers investigating judicial errors against Galileo, after whom the minor planet 697 Galilea is named, and other medieval scientists.<ref name="springer" />
Ratzinger was considered to be one of the most authoritative voices in the Vatican and became Pope Benedict XVI in 2005. The name was proposed by the asteroid's first discoverer, Lutz Schmadel.<ref name="springer" /> The approved naming citation was published by the Minor Planet Center on 23 May 2000 ({{small|M.P.C. 40702}}).<ref name="MPC-Circulars-Archive" />
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2019-08-28 last obs. |title = JPL Small-Body Database Browser: 8661 Ratzinger (1990 TA13) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2008661 |archive-url = https://web.archive.org/web/20191225164009/https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2008661 |archive-date = 25 December 2019 |publisher = Jet Propulsion Laboratory |access-date = 17 April 2020}}</ref>
<ref name="springer">{{cite book |last = Schmadel | first = Lutz D. |title = Dictionary of Minor Planet Names | author-link=Lutz D. Schmadel |publisher = Springer Berlin Heidelberg |page = 659 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_7136 |chapter = (8661) Ratzinger }}</ref>
<ref name="MPC-Ratzinger">{{cite web |title = 8661 Ratzinger (1990 TA13) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=8661 |access-date = 4 July 2016}}</ref>
<ref name="MPC-Circulars-Archive">{{cite web |title = MPC/MPO/MPS Archive |work = Minor Planet Center |url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html |access-date = 4 July 2016}}</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 |s2cid = 118745497 |access-date= 4 December 2016}}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 8661 Ratzinger – Nesvorny HCM Asteroid Families V3.0 |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=8661+Ratzinger#Asteroid%208661%20RatzingerEAR-A-VARGBDET-5-NESVORNYFAM-V3.0 |access-date = 27 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|s2cid = 119280014 }}</ref>
<ref name="lcdb">{{cite LCDB|number = 8661 |access-date = 17 April 2020}}</ref> <ref name="Durech2018">{{cite journal |title = Asteroid models reconstructed from the Lowell PhotometricDatabase and WISE data |arxiv = 1807.02083 |url = https://www.aanda.org/articles/aa/abs/2018/09/aa33437-18/aa33437-18.html |date = September 2018 |access-date = 17 April 2020 |journal = Astronomy & Astrophysics |volume = 617 |doi = 10.1051/0004-6361/201833437 |author1 = Ďurech, J. |author2 = Hanuš, J. |author3 = Alí-Lagoa, V.|pages = A57 |s2cid = 119388288 }}</ref>
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== 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/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center * {{AstDys|8661}} * {{JPL small body}}
{{Minor planets navigator |8660 Sano |number=8661 |(8662) 1990 UT10}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Ratzinger}} 008661 Category:Discoveries by Lutz D. Schmadel Category:Discoveries by Freimut Börngen Category:Named minor planets 8661 Ratzinger 19901014