{{Short description|Centaur}} {{Use dmy dates|date=August 2021}} {{Infobox planet | minorplanet = yes | name = 32532 Thereus | symbol = 24px (astrological) | background = #C7FF8F | image = Орбита астероида 32532.png | image_size = | caption = | discovery_ref = <ref name="jpldata" /> | discoverer = NEAT | discovery_site = Palomar Obs. | discovered = 9 August 2001 | mpc_name = (32532) Thereus | alt_names = {{mp|2001 PT|13}}{{·}}{{mp|1995 MM|6}}<br />{{mp|1999 NE|2}} | pronounced = {{IPAc-en|θ|ɪ|'|r|iː|ə|s}} | named_after = θήρειος βία ''thēreios bia''<ref name="springer" /><ref name=LSJ/> | mp_category = centaur<ref name="jpldata" /><ref name="lcdb" />{{·}}distant<ref name="MPC-object" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 1 | observation_arc = 21.57 yr (7,879 days) | aphelion = 12.745 AU | perihelion = 8.5345 AU | semimajor = 10.640 AU | eccentricity = 0.1979 | period = 34.70 yr (12,676 days) | mean_anomaly = 192.91° | mean_motion = {{Deg2DMS|0.0284|sup=ms}} / day | inclination = 20.353° | asc_node = 205.33° | arg_peri = 86.322° | mean_diameter = {{val|62|3|ul=km}}<ref name="Duffard-2014" /><br />77.19 km {{small|(derived)}}<ref name="lcdb" /><br />{{val|80|5}} km<ref name="Stansberry-2005" /><br />{{val|86.500|1.900}} km<ref name="Bauer-2013" /> | rotation = {{val|8.30|ul=h}}<ref name="Ortiz-2002" /><br />{{val|8.3091}} h<ref name="Ortiz-2003a" /><br />{{val|8.335}} h<ref name="Farnham-2003" /><br />{{val|8.338|0.002}} h<ref name="Brucker-2008" /><br />{{val|8.3386|0.0006}} h<ref name="Rabinowitz-2007" /> | albedo = 0.057 {{small|(assumed)}}<ref name="lcdb" /><br />{{val|0.059|0.013}}<ref name="Bauer-2013" /><br />{{val|0.083|0.016}}<ref name="Duffard-2014" /><br />{{val|0.0975|0.0125}}<ref name="Stansberry-2005" /> | spectral_type = BR<ref name="Lowry-2007b" /><br />B–V = {{val|0.770|0.020}}<ref name="Lowry-2007b" /><br />B–V = {{val|0.810|0.050}}<ref name="DeMeo-2008a" /><br />B–V = {{val|0.763|0.072}}<ref name="Hainaut-2012" /><br />V–R = {{val|0.490|0.010}}<ref name="Lowry-2007b" /><br />V–R = {{val|0.501|0.016}}<ref name="Hainaut-2012" /><br />V–I = {{val|0.940|0.010}}<ref name="Lowry-2007b" /><br />V–I = {{val|0.900|0.130}}<ref name="DeMeo-2008a" /><br />V–I = {{val|0.917|0.035}}<ref name="Hainaut-2012" /> | abs_magnitude = 9.1<ref name="jpldata" />{{·}}9.29<ref name="Farnham-2003" /><ref name="lcdb" />{{·}}9.32<ref name="Romanishin-2005" />{{·}}9.36<ref name="Ortiz-2003a" />{{·}}{{val|9.365|0.038}} {{small|(R)}}<ref name="Peixinho-2012" />{{·}}{{val|9.40|0.16}}<ref name="Duffard-2014" />{{·}}{{val|9.42|0.01}}<ref name="Rabinowitz-2007" /> }}
'''32532 Thereus''' ({{IPAc-en|θ|ɪ|'|r|iː|ə|s}}; provisional designation '''{{mp|2001 PT|13}}''') is a centaur from the outer Solar System, approximately {{convert|80|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 9 August 2001, by astronomers of the Near-Earth Asteroid Tracking program at the Palomar Observatory in California, United States.<ref name="MPC-object" /> This minor planet was named for the phrase ''thēreios bia'' 'beastly strength', used to describe centaurs in Greek mythology.<ref name="springer" /><ref name=LSJ>{{LSJ|qh%2Freios|θήρειος|ref}}</ref>
== Orbit and classification == Thereus orbits the Sun at a distance of 8.5–12.7 AU once every 34 years and 8 months (12,676 days). Its orbit has an eccentricity of 0.20 and an inclination of 20° with respect to the ecliptic.<ref name="jpldata" />
The body's observation arc begins with a precovery taken by Spacewatch at Kitt Peak Observatory in June 1995, more than 6 years prior to its official discovery observation by NEAT at Palomar.<ref name="MPC-object" />
== Naming == This minor planet was named after Thereus, a centaur from Greek mythology. He is described as a hunter who captured bears and carried them home, alive and struggling.<ref name="springer" /> The official naming citation was published by the Minor Planet Center on 14 June 2003 ({{small|M.P.C. 49102}}).<ref name="MPC-Circulars-Archive" />
== Physical characteristics ==
=== Rotation period === Since the early 2000s, several rotational lightcurves of Thereus were obtained from photometric observations with a period between 8.30 and 8.3386 hours.<ref name="Ortiz-2002" /><ref name="Ortiz-2003a" /><ref name="Farnham-2003" /><ref name="Brucker-2008" /><ref name="Rabinowitz-2007" /> Analysis of the consolidated, best-rated lightcurve gave a rotation period of 8.335 hours and a brightness amplitude of 0.38 magnitude ({{small|U=3}}).<ref name="lcdb" />
=== Diameter and albedo === According to observations made by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ESA's Herschel Space Observatory with its PACS instrument, and the Spitzer Space Telescope, Thereus measures between 62 and 86.5 kilometers in diameter and its surface has an albedo between 0.059 and 0.0975.<ref name="Duffard-2014" /><ref name="Stansberry-2005" /><ref name="Bauer-2013" />
The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for carbonaceous minor planets of 0.057 and derives a diameter of 77.19 kilometers based on an absolute magnitude of 9.29.<ref name="lcdb" />
=== Surface Composition === Observations covering different rotational phases indicate that the surface of Thereus is compositionally heterogeneous. Modeling of the reflectance variations suggests that the water-ice abundance is not uniform, but varies across the surface, with estimates ranging from ~0% up to approximately 25% in specific regions. The best-fit scattering models are consistent with intimate mixtures of water ice and refractory components, including olivine, complex organic materials (tholins), and amorphous carbon.<ref name="Licandro-Pinilla-2005" />
== See also == * {{Section link|List of centaurs (small Solar System bodies)|32532}}
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2016-12-30 last obs. |title = JPL Small-Body Database Browser: 32532 Thereus (2001 PT13) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2032532 |publisher = Jet Propulsion Laboratory |access-date= 21 September 2017}}</ref>
<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names – Addendum to Fifth Edition: 2003–2005 |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |chapter = (32532) Thereus [10.6, 0.20, 20.4] |page = 199 |date = 2006 |isbn = 978-3-540-34361-5 |doi = 10.1007/978-3-540-34361-5_2336}}</ref>
<ref name="MPC-object">{{cite web |title = 32532 Thereus (2001 PT13) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=32532 |access-date= 21 September 2017}}</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= 21 September 2017}}</ref>
<ref name="Bauer-2013">{{Cite journal |display-authors = 6 |first1 = James M. |last1 = Bauer |first2 = Tommy |last2 = Grav |first3 = Erin |last3 = Blauvelt |first4 = A. K. |last4 = Mainzer |first5 = Joseph R. |last5 = Masiero |first6 = Rachel |last6 = Stevenson |first7 = Emily |last7 = Kramer |first8 = Yan R. |last8 = Fernández |first9 = C. M. |last9 = Lisse |first10 = Roc M. |last10 = Cutri |first11 = Paul R. |last11 = Weissman |first12 = John W. |last12 = Dailey |first13 = Frank J. |last13 = Masci |first14 = Russel |last14 = Walker |first15 = Adam |last15 = Waszczak |first16 = Carrie R. |last16 = Nugent |first17 = Karen J. |last17 = Meech |first18 = Andrew |last18 = Lucas |first19 = George |last19 = Pearman |first20 = Ashlee |last20 = Wilkins |first21 = Jessica |last21 = Watkins |first22 = Shrinivas |last22 = Kulkarni |first23 = Edward L. |last23 = Wright |last24 = WISE Team |last25 = PTF Team |date = August 2013 |title = Centaurs and Scattered Disk Objects in the Thermal Infrared: Analysis of WISE/NEOWISE Observations |journal = The Astrophysical Journal |volume = 773 |issue = 1 |page = 11 |bibcode = 2013ApJ...773...22B |doi = 10.1088/0004-637X/773/1/22 |arxiv = 1306.1862|s2cid = 51139703 }}</ref>
<ref name="lcdb">{{cite LCDB|number = 32532 |access-date= 21 September 2017}}</ref>
<ref name="Stansberry-2005">{{Cite journal |display-authors = 6 |first1 = J. A. |last1 = Stansberry |first2 = D. P. |last2 = Cruikshank |first3 = W. G. |last3 = Grundy |first4 = J. L. |last4 = Margot |first5 = J. P. |last5 = Emery |first6 = Y. R. |last6 = Fernandez |first7 = G. H. |last7 = Rieke |date = August 2005 |title = Albedos, Diameters (and a Density) of Kuiper Belt and Centaur Objects |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2005DPS....37.5205S |journal = American Astronomical Society |volume = 37 |page = 737 |bibcode = 2005DPS....37.5205S |access-date= 21 September 2017}}</ref>
<ref name="Licandro-Pinilla-2005">{{Cite journal |first1 = Javier |last1 = Licandro |first2 = Noemi |last2 = Pinilla-Alonso |date = September 2005 |title = The Inhomogeneous Surface of Centaur 32522 Thereus (2001 PT$_{13}$) |journal = Astrophysical Journal Letters |volume = 630 |issue = 1 |pages = L93–L96 |doi = 10.1086/491469 |url = https://ui.adsabs.harvard.edu/abs/2005ApJ...630L..93L |access-date= 23 February 2026 }}</ref>
<ref name="Duffard-2014">{{cite journal |display-authors = 6 |first1 = R. |last1 = Duffard |first2 = N. |last2 = Pinilla-Alonso |first3 = P. |last3 = Santos-Sanz |first4 = E. |last4 = Vilenius |first5 = J. L. |last5 = Ortiz |first6 = T. |last6 = Mueller |first7 = S. |last7 = Fornasier |first8 = E. |last8 = Lellouch |first9 = M. |last9 = Mommert |first10 = A. |last10 = Pal |first11 = C. |last11 = Kiss |first12 = M. |last12 = Mueller |first13 = J. |last13 = Stansberry |first14 = A. |last14 = Delsanti |first15 = N. |last15 = Peixinho |first16 = D. |last16 = Trilling |date = April 2014 |title = "TNOs are Cool": A survey of the trans-Neptunian region. XI. A Herschel-PACS view of 16 Centaurs |journal = Astronomy and Astrophysics |volume = 564 |page = 17 |bibcode = 2014A&A...564A..92D |doi = 10.1051/0004-6361/201322377 |arxiv = 1309.0946|s2cid = 119177446 }}</ref>
<ref name="Ortiz-2002">{{Cite journal |first1 = J. L. |last1 = Ortiz |first2 = S. |last2 = Baumont |first3 = P. J. |last3 = Gutiérrez |first4 = M. |last4 = Roos-Serote |date = June 2002 |title = Lightcurves of Centaurs 2000 QC243 and 2001 PT13 |journal = Astronomy and Astrophysics |volume = 388 |issue = 2 |pages = 661–666 |bibcode = 2002A&A...388..661O |doi = 10.1051/0004-6361:20020487 |doi-access = free}}</ref>
<ref name="Farnham-2003">{{Cite journal |first1 = Tony L. |last1 = Farnham |first2 = John K. |last2 = Davies |date = August 2003 |title = The rotational and physical properties of the Centaur (32532) 2001 PT 13 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2003Icar..164..418F |journal = Icarus |volume = 164 |issue = 2 |pages = 418–427 |bibcode = 2003Icar..164..418F |doi = 10.1016/S0019-1035(03)00141-6 |access-date= 21 September 2017}}</ref>
<ref name="Ortiz-2003a">{{Cite journal |first1 = J. L. |last1 = Ortiz |first2 = P. J. |last2 = Gutiérrez |first3 = V. |last3 = Casanova |first4 = A. |last4 = Sota |date = September 2003 |title = A study of short term rotational variability in TNOs and Centaurs from Sierra Nevada Observatory |journal = Astronomy and Astrophysics |volume = 407 |issue = 3 |pages = 1149–1155 |bibcode = 2003A&A...407.1149O |doi = 10.1051/0004-6361:20030972 |doi-access = free}}</ref>
<ref name="Rabinowitz-2007">{{Cite journal |first1 = David L. |last1 = Rabinowitz |first2 = Bradley E. |last2 = Schaefer |first3 = Suzanne W. |last3 = Tourtellotte |date = January 2007 |title = The Diverse Solar Phase Curves of Distant Icy Bodies. I. Photometric Observations of 18 Trans-Neptunian Objects, 7 Centaurs, and Nereid |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2007AJ....133...26R |journal = The Astronomical Journal |volume = 133 |issue = 1 |pages = 26–43 |bibcode = 2007AJ....133...26R |doi = 10.1086/508931 |arxiv = astro-ph/0605745 |s2cid = 119406900 |access-date= 21 September 2017}}</ref>
<ref name="Brucker-2008">{{Cite journal |first1 = Melissa |last1 = Brucker |first2 = W. J. |last2 = Romanishin |first3 = S. C. |last3 = Tegler |first4 = G. J. |last4 = Consolmagno |first5 = S. |last5 = J. |first6 = W. M. |last6 = Grundy |date = September 2008 |title = Rotational Properties of Centaurs (32532) Thereus and (8405) Asbolus |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2008DPS....40.4709B |journal = American Astronomical Society |volume = 40 |page = 483 |bibcode = 2008DPS....40.4709B |access-date= 21 September 2017}}</ref>
<ref name="Romanishin-2005">{{Cite journal |first1 = W. |last1 = Romanishin |first2 = S. C. |last2 = Tegler |date = December 2005 |title = Accurate absolute magnitudes for Kuiper belt objects and Centaurs |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2005Icar..179..523R |journal = Icarus |volume = 179 |issue = 2 |pages = 523–526 |bibcode = 2005Icar..179..523R |doi = 10.1016/j.icarus.2005.06.016 |access-date= 21 September 2017}}</ref>
<ref name="Peixinho-2012">{{cite journal |first1 = N. |last1 = Peixinho |first2 = A. |last2 = Delsanti |first3 = A. |last3 = Guilbert-Lepoutre |first4 = R. |last4 = Gafeira |first5 = P. |last5 = Lacerda |date = October 2012 |title = The bimodal colors of Centaurs and small Kuiper belt objects |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012A&A...546A..86P |journal = Astronomy and Astrophysics |volume = 546 |page = 12 |bibcode = 2012A&A...546A..86P |doi = 10.1051/0004-6361/201219057 |arxiv = 1206.3153 |s2cid = 55876118 |access-date= 21 September 2017}}</ref>
<ref name="Lowry-2007b">{{Cite journal |first1 = Stephen C. |last1 = Lowry |first2 = Paul R. |last2 = Weissman |date = May 2007 |title = Rotation and color properties of the nucleus of Comet 2P/Encke |journal = Icarus |volume = 188 |issue = 1 |pages = 212–223 |bibcode = 2007Icar..188..212L |doi = 10.1016/j.icarus.2006.11.014 |arxiv = astro-ph/0612380|s2cid = 119024049 }}</ref>
<ref name="DeMeo-2008a">{{Cite journal |display-authors = 6 |first1 = Francesca E. |last1 = DeMeo |first2 = S. |last2 = Fornasier |first3 = M. A. |last3 = Barucci |first4 = D. |last4 = Perna |first5 = S. |last5 = Protopapa |first6 = A. |last6 = Alvarez-Candal |first7 = A. |last7 = Delsanti |first8 = A. |last8 = Doressoundiram |first9 = F. |last9 = Merlin |first10 = C. |last10 = de Bergh |date = September 2008 |title = Visible and Near-infrared Colors of TNOs from the Second ESO Large Program |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2008DPS....40.4705D |journal = American Astronomical Society |volume = 40 |page = 482 |bibcode = 2008DPS....40.4705D |access-date= 21 September 2017}}</ref>
<ref name="Hainaut-2012">{{Cite journal |first1 = O. R. |last1 = Hainaut |first2 = H. |last2 = Boehnhardt |first3 = S. |last3 = Protopapa |date = October 2012 |title = Colours of minor bodies in the outer solar system. II. A statistical analysis revisited |journal = Astronomy and Astrophysics |volume = 546 |page = 20 |bibcode = 2012A&A...546A.115H |doi = 10.1051/0004-6361/201219566 |arxiv = 1209.1896|s2cid = 54776793 }}</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/NumberedMPs030001.html Discovery Circumstances: Numbered Minor Planets (30001)-(35000)] – Minor Planet Center * {{AstDys|32532}} * {{JPL small body}}
{{Minor planets navigator |32531 Ulrikababiaková |number=32532 |32533 Tranpham}} {{Small Solar System bodies}} {{Authority control}}
{{DEFAULTSORT:Thereus}} Category:Centaurs (small Solar System bodies) 032532 Category:Named minor planets 20010809