1091 Spiraea

{{Short description|Carbonaceous main-belt asteroid}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1091 Spiraea | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="jpldata" /> | discoverer = K. Reinmuth | discovery_site = Heidelberg Obs. | discovered = 26 February 1928 | mpc_name = (1091) Spiraea | alt_names = 1928 DT{{·}}{{mp|1934 CN|1}} 1938 UR{{·}}1964 XH | pronounced = {{IPAc-en|s|p|aɪ|ˈ|r|iː|ə}}<ref>{{OED|spiræa}}</ref> | named_after = Spiraea {{small|(genus of shrubs)}}<ref name="springer" /> | mp_category = main-belt{{·}}{{small|(outer)}}<ref name="jpldata" /><ref name="lcdb" /> Cybele{{·}}background<ref name="AstDys-object" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 89.27 yr (32,606 days) | aphelion = 3.6484 AU | perihelion = 3.2077 AU | semimajor = 3.4281 AU | eccentricity = 0.0643 | period = 6.35 yr (2,318 days) | mean_anomaly = 110.37° | mean_motion = {{Deg2DMS|0.1553|sup=ms}} / day | inclination = 1.1554° | asc_node = 80.790° | arg_peri = 12.062° | dimensions = 32.78 km {{small|(calculated)}}<ref name="lcdb" /> {{val|35.178|0.108}} km<ref name="Masiero-2014" /> {{val|39.92|17.85}} km<ref name="Nugent-2016" /> {{val|40.280|0.455}} km<ref name="WISE" /> {{val|40.52|0.91}} km<ref name="AKARI" /> | rotation = {{val|7.01|0.43}} h<ref name="Chang-2016" /> | albedo = {{val|0.05|0.06}}<ref name="Nugent-2016" /> 0.057 {{small|(assumed)}}<ref name="lcdb" /> {{val|0.0627|0.0106}}<ref name="WISE" /> {{val|0.063|0.003}}<ref name="AKARI" /> {{val|0.091|0.025}}<ref name="Masiero-2014" /> | spectral_type = C {{small|(assumed)}}<ref name="lcdb" /> | abs_magnitude = 10.60<ref name="WISE" /><ref name="AKARI" />{{·}}{{val|10.70|0.08}} {{small|(R)}}<ref name="Chang-2016" />{{·}}10.8<ref name="jpldata" />{{·}}{{val|11.00|0.14}}<ref name="Veres-2015" />{{·}}11.15<ref name="lcdb" />{{·}}11.18<ref name="Nugent-2016" /> }}

'''1091 Spiraea''', provisional designation {{mp|1928 DT}}, is a carbonaceous Cybele asteroid from the outer regions of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 26 February 1928, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany.<ref name="MPC-object" /> The asteroid was named after ''Spiraea'', a genus of plants.<ref name="springer" />

== Orbit and classification ==

''Spiraea'' orbits the Sun in the outer main-belt at a distance of 3.2–3.6 AU once every 6 years and 4 months (2,318 days). Its orbit has an eccentricity of 0.06 and an inclination of 1° with respect to the ecliptic.<ref name="jpldata" /> With these orbital parameters, it belongs to the Cybele asteroids, a dynamical group near the 4:7 resonance with Jupiter and named after one of the largest asteroids, 65 Cybele. It is, however, a non-family asteroid from the main belt's background population when applying the hierarchical clustering method (Nesvorny, Novakovic, Knezevic and Milani) to its proper orbital elements.<ref name="AstDys-object" />

The body's observation arc begins with its identification as {{mp|1934 CN|1}} at Uccle Observatory in February 1934, almost six years after its official discovery observation at Heidelberg.<ref name="MPC-object" />

== Physical characteristics ==

''Spiraea'' is an assumed carbonaceous C-type asteroid.<ref name="lcdb" />

=== Rotation period ===

In December 2014, a fragmentary rotational lightcurve of ''Spiraea'' was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 7.01 hours with a brightness amplitude of 0.03 magnitude ({{small|U=1+}}).<ref name="Chang-2016" />

=== Diameter and albedo ===

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Spiraea'' measures between 35.178 and 40.52 kilometers in diameter and its surface has an albedo between 0.05 and 0.091.<ref name="Masiero-2014" /><ref name="Nugent-2016" /><ref name="WISE" /><ref name="AKARI" />

The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 32.78 kilometers based on an absolute magnitude of 11.15.<ref name="lcdb" />

== Naming ==

This minor planet was named after ''Spiraea'', a genus of shrubs of the rose family (Rosaceae), with small white or pink flowers. The official naming citation was mentioned in ''The Names of the Minor Planets'' by Paul Herget in 1955 ({{small|H 103}}).<ref name="springer" />

=== Reinmuth's flowers ===

Due to his many discoveries, Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between {{MoMP|1009|(1009)}} and {{MoMP|1200|(1200)}}. This list also contained a sequence of 28 asteroids, starting with 1054 Forsytia, that were all named after plants, in particular flowering plants ''(also see list of minor planets named after animals and plants)''.<ref name="springer-flowers" />

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

<ref name="jpldata">{{cite web |type = 2017-06-04 last obs. |title = JPL Small-Body Database Browser: 1091 Spiraea (1928 DT) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001091 |publisher = Jet Propulsion Laboratory |accessdate = 26 September 2017}}</ref>

<ref name="springer">{{cite book |last = Schmadel | first = Lutz D. |title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg |page = 93 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1092 |chapter = (1091) Spiraea }}</ref>

<ref name="springer-flowers">{{cite book |last = Schmadel | first = Lutz D. |title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg |page = 90 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1055 |chapter = (1054) Forsytia }}</ref>

<ref name="MPC-object">{{cite web |title = 1091 Spiraea (1928 DT) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1091 |accessdate = 26 September 2017}}</ref>

<ref name="Masiero-2014">{{cite journal |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 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M |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 |s2cid = 119293330 |access-date= 26 September 2017}}</ref>

<ref name="AstDys-object">{{cite web |title = Asteroid 1091 Spiraea – Proper Elements |publisher = AstDyS-2, Asteroids – Dynamic Site |url = https://newton.spacedys.com/astdys/index.php?pc=1.1.6&n=1091 |access-date= 28 October 2019}}</ref>

<ref name="lcdb">{{cite LCDB|number = 1091 |accessdate = 26 September 2017}}</ref>

<ref name="Nugent-2016">{{cite journal |display-authors = 6 |first1 = C. R. |last1 = Nugent |first2 = A. |last2 = Mainzer |first3 = J. |last3 = Bauer |first4 = R. M. |last4 = Cutri |first5 = E. A. |last5 = Kramer |first6 = T. |last6 = Grav |first7 = J. |last7 = Masiero |first8 = S. |last8 = Sonnett |first9 = E. L. |last9 = Wright |date = September 2016 |title = NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos |journal = The Astronomical Journal |volume = 152 |issue = 3 |page = 12 |bibcode = 2016AJ....152...63N |doi = 10.3847/0004-6256/152/3/63 |arxiv = 1606.08923 |doi-access = free }}</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=1091 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="Chang-2016">{{cite journal |display-authors = 6 |first1 = Chan-Kao |last1 = Chang |first2 = Hsing-Wen |last2 = Lin |first3 = Wing-Huen |last3 = Ip |author-link3= Ip Wing-huen |first4 = Thomas A. |last4 = Prince |first5 = Shrinivas R. |last5 = Kulkarni |first6 = David |last6 = Levitan |first7 = Russ |last7 = Laher |first8 = Jason |last8 = Surace |date = December 2016 |title = Large Super-fast Rotator Hunting Using the Intermediate Palomar Transient Factory |journal = The Astrophysical Journal Supplement Series |volume = 227 |issue = 2 |page = 13 |bibcode = 2016ApJS..227...20C |doi = 10.3847/0067-0049/227/2/20 |arxiv = 1608.07910 |s2cid = 30387146 |doi-access = free }}</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= 26 September 2017}}</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/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1091}} * {{JPL small body}}

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{{DEFAULTSORT:Spiraea}} 001091 Category:Discoveries by Karl Wilhelm Reinmuth Category:Named minor planets 19280226