1180 Rita

{{Short description|Main-belt asteroid}} {{Use dmy dates|date=December 2019}} {{Infobox planet | minorplanet = yes | name = 1180 Rita | background = #D6D6D6 | image = | caption = | discovery_ref = <ref name="jpldata" /> | discovered = 9 April 1931 | discoverer = K. Reinmuth | discovery_site = Heidelberg Obs. | mpc_name = (1180) Rita | alt_names = 1931 GE{{·}}1929 CM 1953 AH{{·}}{{mp|1957 UF|1}} A907 GG{{·}}A908 KA A916 LA | pronounced = | named_after = unknown<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(outer)}}<ref name="jpldata" />{{·}}Hilda<ref name="MPC-Rita" /><ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 16 February 2017 (JD 2457800.5) | uncertainty = 0 | observation_arc = 109.98 yr (40,172 days) | aphelion = 4.6127 AU | perihelion = 3.3574 AU | semimajor = 3.9851 AU | eccentricity = 0.1575 | period = 7.96 yr (2,906 days) | mean_anomaly = 209.15° | mean_motion = {{Deg2DMS|0.1239|sup=ms}} / day | inclination = 7.1985° | asc_node = 88.336° | arg_peri = 209.12° | jupiter_moid = 0.6111 AU | mean_diameter = 82.72 km {{small|(calculated)}}<ref name="lcdb" /> 97 km<ref name="jpldata" /> {{val|97.63|2.30}} km<ref name="AKARI" /> | rotation = {{val|9}} h<ref name="Binzel-1992a" /> {{val|9.605|0.006}} h<ref name="Polishook-2012e" /> {{val|12|}} h<ref name="geneva-obs" /> {{val|13.090|0.002}} h{{efn|name=LCDB-Warner-2017}} {{val|14.72}} h<ref name="Gonano-1991" /> {{val|14.902}} h<ref name="Dahlgren-1998" /> {{val|20.496|0.005}} h{{efn|name=LCDB-Slyusarev-2012}} | albedo = {{val|0.041|0.002}}<ref name="AKARI" /> {{val|0.044|0.008}}<ref name="WISE" /> {{val|0.048}}<ref name="jpldata" /> 0.057 {{small|(assumed)}}<ref name="lcdb" /> {{val|0.058|0.009}}<ref name="Grav-2012a" /> | spectral_type = Tholen = P<ref name="jpldata" />{{·}}P<ref name="lcdb" /><ref name="WISE" /> {{nowrap|B–V {{=}} 0.682<ref name="jpldata" />{{·}}{{val|0.670|0.010}}{{efn|name=LCDB-Slyusarev-2012}}}} U–B = 0.216<ref name="jpldata" /> V–R = {{val|0.440|0.010}}{{efn|name=LCDB-Slyusarev-2012}} | abs_magnitude = 9.14<ref name="jpldata" /><ref name="lcdb" /><ref name="AKARI" />{{·}}{{val|9.17|0.19}}<ref name="Veres-2015" /> }}

'''1180 Rita''', provisional designation {{mp|1931 GE}}, is a dark and spheroidal Hildian asteroid from the outermost regions of the asteroid belt, approximately 97 kilometers in diameter. It was discovered on 9 April 1931, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.<ref name="MPC-Rita" /> Any reference of its later name, ''Rita'', is unknown.<ref name="springer" />

== Orbit and classification ==

''Rita'' belongs to the orbital Hilda group which is located in the outermost part of the main-belt.<ref name="lcdb" /> Asteroids in this dynamical group have semi-major axis between 3.7 and 4.2 AU and stay in a 3:2 resonance with the gas giant Jupiter. ''Rita'', however, is a background asteroid and not a member of the (collisional) Hilda family ({{small|101}}).<ref name="AstDys-object" /> Hildian asteroids are thought to have originated from the Kuiper belt.

The asteroid orbits the Sun at a distance of 3.4–4.6 AU once every 7 years and 12 months (2,906 days). Its orbit has an eccentricity of 0.16 and an inclination of 7° with respect to the ecliptic.<ref name="jpldata" />

It was first observed as {{mp|A907 GG}} at Heidelberg in 1907. The body's observation arc begins at Heidelberg in 1908, when it was identified as {{mp|A908 KA}}, approximately 23 years prior to its official discovery observation.<ref name="MPC-Rita" />

== Physical characteristics ==

In the Tholen taxonomy, ''Rita'' is a dark and reddish P-type asteroid.<ref name="jpldata" /> The P-type asteroids are some of the darkest objects in the Solar System.

=== Rotation period ===

Since 1983, several rotational lightcurves of ''Rita'' have been obtained from photometric observations. Lightcurve analysis gave a wide range of divergent rotation periods between 9 and 20.5 hours.<ref name="Binzel-1992a" /><ref name="Polishook-2012e" /><ref name="geneva-obs" /><ref name="Gonano-1991" /><ref name="Dahlgren-1998" />{{efn|name=LCDB-Slyusarev-2012}} The ''Light Curve Data Base'' adopts a period of 13.090 hours with a brightness amplitude of 0.06 magnitude. Bodies with such a low brightness variation are typically of a spherical rather than elongated shape. The lightcurve was obtained in January 2017, by American astronomer Brian Warner at the Center for Solar System Studies in California ({{small|U=2}}).{{efn|name=LCDB-Warner-2017}}

=== Diameter and albedo ===

According to the surveys carried out by the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ''Rita'' measures 97 kilometers in diameter and its surface has an albedo between 0.041 and 0.058.<ref name="AKARI" /><ref name="WISE" /><ref name="Grav-2012a" /> The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for carbonaceous, outer main-belt asteroids of 0.057, and calculates a diameter of 82.72 kilometers with on an absolute magnitude of 9.14.<ref name="lcdb" />

== Naming ==

Any reference of this minor planet's name to a person or occurrence is unknown.<ref name="springer" />

=== Unknown meaning ===

Among the many thousands of named minor planets, ''Rita'' 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" />

== Notes == {{notelist|refs=

{{efn|name=LCDB-Warner-2017|1=Warner (2017) web: [http://www.planetarysciences.org/plots/BDW/1180_RITA_20161212.PNG lightcurve plot] of {{mp|1180 Rita}} – rotation period {{val|13.090|0.002}} hours with a brightness amplitude of {{val|0.06|0.01}} magnitude. No quality code of 2. Observed between 12 December 2016 and 26 January 2017, with a total of 304 data points. Summary figures at the [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1180%7CRita Light Curve Data Base].}}

{{efn|name=LCDB-Slyusarev-2012|1=Slyusarev (2012) web: rotation period {{val|20.496|0.005}} hours with a brightness amplitude of {{val|0.05}} magnitude. No quality code determined. Color Indices for BV and VR are {{val|0.670|0.010}} and {{val|0.440|0.010}}, respectively. Summary figures at the [http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1180%7CRita Light Curve Data Base].}}

}}

== References == {{reflist|30em|refs=

<ref name="jpldata">{{cite web |type = 2017-03-29 last obs. |title = JPL Small-Body Database Browser: 1180 Rita (1931 GE) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001180 |publisher = Jet Propulsion Laboratory |accessdate = 27 April 2017}}</ref>

<ref name="springer">{{cite book |last = Schmadel | first = Lutz D. |title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg |page = 99 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1181 |chapter = (1180) Rita }}</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-Rita">{{cite web |title = 1180 Rita (1931 GE) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1180 |accessdate = 27 April 2017}}</ref>

<ref name="geneva-obs">{{cite web |title = Asteroids and comets rotation curves – (1180) Rita |last = Behrend |first = Raoul |publisher = Geneva Observatory |url = http://obswww.unige.ch/~behrend/page3cou.html#001180 |accessdate = 27 April 2017}}</ref>

<ref name="Grav-2012a">{{Cite journal |display-authors = 6 |first1 = T. |last1 = Grav |first2 = A. K. |last2 = Mainzer |first3 = J. |last3 = Bauer |first4 = J. |last4 = Masiero |first5 = T. |last5 = Spahr |first6 = R. S. |last6 = McMillan |first7 = R. |last7 = Walker |first8 = R. |last8 = Cutri |first9 = E. |last9 = Wright |first10 = P. R. |last10 = Eisenhardt |first11 = E. |last11 = Blauvelt |first12 = E. |last12 = DeBaun |first13 = D. |last13 = Elsbury |first14 = T. |last14 = Gautier |first15 = S. |last15 = Gomillion |first16 = E. |last16 = Hand |first17 = A. |last17 = Wilkins |date = January 2012 |title = WISE/NEOWISE Observations of the Hilda Population: Preliminary Results |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...744..197G |journal = The Astrophysical Journal |volume = 744 |issue = 2 |page = 15 |bibcode = 2012ApJ...744..197G |doi = 10.1088/0004-637X/744/2/197 |arxiv = 1110.0283 |s2cid = 44000310 |access-date= 27 April 2017}}</ref>

<ref name="AstDys-object">{{cite web |title = Asteroid 1180 Rita – Proper Elements |publisher = AstDyS-2, Asteroids – Dynamic Site |url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1180 |access-date= 28 October 2019}}</ref>

<ref name="lcdb">{{cite LCDB|number = 1180 |accessdate = 27 April 2017}}</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=1180 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])</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|s2cid = 35447010 }}</ref>

<ref name="Gonano-1991">{{Cite journal |first1 = M. |last1 = Gonano |first2 = S. |last2 = Mottola |first3 = G. |last3 = Neukum |first4 = M. |last4 = di Martino |date = December 1990 |title = Physical study of outer belt asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1991AdSpR..11..197G |journal = Space Dust and Debris; Proceedings of the Topical Meeting of the Interdisciplinary Scientific Commission B /Meetings B2 |volume = 11 |issue = 12 |pages = 197–200 |issn = 0273-1177 |bibcode = 1991AdSpR..11l.197G |doi = 10.1016/0273-1177(91)90563-Y |access-date= 27 April 2017}}</ref>

<ref name="Binzel-1992a">{{Cite journal |first1 = Richard P. |last1 = Binzel |first2 = Linda M. |last2 = Sauter |date = February 1992 |title = Trojan, Hilda, and Cybele asteroids - New lightcurve observations and analysis |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1992Icar...95..222B |journal = Icarus |volume = 95 |issue = 2 |pages = 222–238 |issn = 0019-1035 |bibcode = 1992Icar...95..222B |doi = 10.1016/0019-1035(92)90039-A |access-date= 27 April 2017}}</ref>

<ref name="Dahlgren-1998">{{Cite journal |display-authors = 6 |first1 = M. |last1 = Dahlgren |first2 = J. F. |last2 = Lahulla |first3 = C.-I. |last3 = Lagerkvist |first4 = J. |last4 = Lagerros |first5 = S. |last5 = Mottola |first6 = A. |last6 = Erikson |first7 = M. |last7 = Gonano-Beurer |first8 = M. |last8 = Di Martino |date = June 1998 |title = A Study of Hilda Asteroids. V. Lightcurves of 47 Hilda Asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=1998Icar..133..247D |journal = Icarus |volume = 133 |issue = 2 |pages = 247–285 |bibcode = 1998Icar..133..247D |doi = 10.1006/icar.1998.5919 |access-date= 27 April 2017}}</ref>

<ref name="Polishook-2012e">{{Cite journal |author = Polishook, David |date = October 2012 |title = Lightcurves for Shape Modeling: 852 Wladilena, 1089 Tama, and 1180 Rita |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012MPBu...39..242P |journal = The Minor Planet Bulletin |volume = 39 |issue = 4 |pages = 242–244 |issn = 1052-8091 |bibcode = 2012MPBu...39..242P |access-date= 27 April 2017}}</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 |s2cid = 53493339 |access-date= 27 April 2017}}</ref>

}}

== 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|1180}} * {{JPL small body}}

{{Minor planets navigator |1179 Mally |number=1180 |1181 Lilith}} {{Small Solar System bodies}} {{Authority control}}

{{DEFAULTSORT:Rita}} 001180 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 001180 19310409