4902 Thessandrus
{{Use dmy dates|date=June 2018}}
{{Infobox planet
| minorplanet = yes
| name = 4902 Thessandrus
| background = #C2FFFF
| image =
| image_size =
| caption =
| discoverer = C. Shoemaker
| discovery_site = Palomar Obs.
| discovered = 9 January 1989
| mpc_name = (4902) Thessandrus
| alt_names = {{mp|1989 AN|2}}{{·}}{{mp|1985 TK|3}}
| adjective = Thessandrian
| pronounced = {{IPAc-en|θ|ᵻ|ˈ|s|æ|n|d|r|ə|s}}
| named_after = Thessander
{{small|(Greek mythology)}}
| mp_category = Jupiter trojan
{{nowrap|Greek{{·}}background}}
| epoch = 23 March 2018 (JD 2458200.5)
| uncertainty = 0
| observation_arc = 64.23 yr (23,459 d)
| aphelion = 5.4234 AU
| perihelion = 4.9858 AU
| semimajor = 5.2046 AU
| eccentricity = 0.0420
| period = 11.87 yr (4,337 d)
| mean_anomaly = 204.25°
| mean_motion = {{Deg2DMS|0.0830|sup=ms}} / day
| inclination = 9.0728°
| asc_node = 170.29°
| arg_peri = 270.62°
| jupiter_moid = 0.1982 AU
| tisserand = 2.9730
| mean_diameter = {{val|51.26|0.66|ul=km}}
61.04 km {{small|(calculated)}}
{{val|71.79|2.84|u=km}}
| rotation = {{val|738|20|ul=h}}
| albedo = {{val|0.057}} {{small|(assumed)}}
{{val|0.060|0.006}}
{{val|0.081|0.012}}
| spectral_type = D {{small|(Pan-STARRS)}}
D {{small|(SDSS-MOC)}}
V–I {{=}} {{val|0.960|0.044}}
}}
4902 Thessandrus {{IPAc-en|θ|ᵻ|ˈ|s|æ|n|d|r|ə|s}} is a Jupiter trojan from the Greek camp, approximately {{convert|60|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 9 January 1989, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California, and later named after Thessander (Thessandrus) from Greek mythology. The dark D-type asteroid is an exceptionally slow rotator and tumbler. It belongs to the 70 largest Jupiter trojans.
Orbit and classification
Thessandrus is a dark Jovian asteroid orbiting in the leading Greek camp at Jupiter's {{L4}} Lagrangian point, 60° ahead of the Gas Giant's orbit in a 1:1 resonance {{crossreference|(see Trojans in astronomy)}}. It is also a non-family asteroid in the Jovian background population.
It orbits the Sun at a distance of 5.0–5.4 AU once every 11 years and 10 months (4,337 days; semi-major axis of 5.2 AU). Its orbit has an eccentricity of 0.04 and an inclination of 9° with respect to the ecliptic.
A first precovery was taken at the discovering observatory in 1954, extending the body's observation arc by 35 years prior to its official discovery observation.
Physical characteristics
Thessandrus has been characterized as a D-type asteroid by Pan-STARRS' survey. It is also a D-type in the SDSS-based taxonomy.
= Slow rotator =
In February 2013, a rotational lightcurve of Thessandrus was obtained from photometric observations by American astronomer Robert Stephens at the Center for Solar System Studies {{Obscode|U81}} in California. It gave an exceptionally long rotation period of {{val|738|20}} hours with a brightness variation of 0.60 in magnitude ({{small|U=2}}). It belongs to the slowest rotators known to exist.
= Tumbler =
The astronomers also detected a non-principal axis rotation seen in distinct rotational cycles in successive order. This is commonly known as tumbling. Thessandrus is the fourth-largest asteroid and largest Jupiter trojan known to be is such a state (also see List of tumblers).
= 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, Thessandrus measures between 51.26 and 71.79 kilometers in diameter and its surface has an albedo between 0.060 and 0.081.
The Collaborative Asteroid Lightcurve Link assumes a standard albedo of a carbonaceous asteroid of 0.057 and calculates a diameter of 61.04 kilometers based on an absolute magnitude of 9.8.
{{Largest Jupiter trojans}}
Naming
This minor planet is named after Thessander (Thessandrus) from Greek mythology and Homer's Iliad. Together with 30 other Greek soldiers he hid in the Trojan horse's belly. The official naming citation was published by the Minor Planet Center on 4 June 1993 ({{small|M.P.C. 22248}}).
References
{{reflist|30em|refs=
|type = 2018-05-20 last obs.
|title = JPL Small-Body Database Browser: 4902 Thessandrus (1989 AN2)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2004902
|publisher = Jet Propulsion Laboratory
|access-date = 17 June 2018}}
|last = Schmadel | first = Lutz D.
|title = Dictionary of Minor Planet Names |publisher = Springer Berlin Heidelberg
|page = 423
|date = 2007
|isbn = 978-3-540-00238-3
|doi = 10.1007/978-3-540-29925-7_4792 |chapter = (4902) Thessandrus }}
|title = 4902 Thessandrus (1989 AN2)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=4902
|access-date = 17 June 2018}}
|title = List of Jupiter Trojans
|work = Minor Planet Center
|first3 = V. |last3 = Carruba
|date = 1 June 2018
|url = https://www.minorplanetcenter.net/iau/lists/JupiterTrojans.html
|access-date = 17 June 2018}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|access-date = 17 June 2018}}
|first1 = T. |last1 = Grav
|first2 = A. K. |last2 = Mainzer
|first3 = J. M. |last3 = Bauer
|first4 = J. R. |last4 = Masiero
|first5 = C. R. |last5 = Nugent
|date = November 2012
|title = WISE/NEOWISE Observations of the Jovian Trojan Population: Taxonomy
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2012ApJ...759...49G
|journal = The Astrophysical Journal
|volume = 759
|issue = 1
|page = 10
|bibcode = 2012ApJ...759...49G
|doi = 10.1088/0004-637X/759/1/49
|arxiv = 1209.1549
|s2cid = 119101711
|access-date= 17 June 2018}} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-6?-source=J/ApJ/759/49/table1&MPC=04902 online catalog])
|title = Asteroid (4902) Thessandrus – Proper Elements
|publisher = AstDyS-2, Asteroids – Dynamic Site
|url = https://newton.spacedys.com/astdys/index.php?n=4902&pc=1.1.6
|access-date= 17 June 2018}}
|first1 = J. M. |last1 = Carvano
|first2 = P. H. |last2 = Hasselmann
|first3 = D. |last3 = Lazzaro
|first4 = T. |last4 = Mothé-Diniz
|date = February 2010
|title = SDSS-based taxonomic classification and orbital distribution of main belt asteroids
|url = https://sbnarchive.psi.edu/pds3/non_mission/EAR_A_I0035_5_SDSSTAX_V1_1/data/sdsstax_ast_table.tab
|journal = Astronomy and Astrophysics
|volume = 510
|page = 12
|bibcode = 2010A&A...510A..43C
|doi = 10.1051/0004-6361/200913322
|access-date= 30 October 2019|doi-access= free
}} [https://sbn.psi.edu/pds/resource/sdsstax.html (PDS data set)]
|title = LCDB Data for (4902) Thessandrus
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=4902%7CThessandrus
|access-date = 30 June 2016}}
|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= free
}} ([http://vizier.cfa.harvard.edu/viz-bin/VizieR-5?-source=J/PASJ/63/1117/acua_v1&Num=4902 online], [https://core.ac.uk/download/pdf/43545172.pdf AcuA catalog p. 153])
|first1 = Linda M. |last1 = French
|first2 = Robert, D. |last2 = Stephens
|first3 = Daniel R. |last3 = Coley
|first4 = Lawrence H. |last4 = Wasserman
|first5 = Faith |last5 = Vilas
|first6 = Daniel |last6 = La Rocca
|date = October 2013
|title = A Troop of Trojans: Photometry of 24 Jovian Trojan Asteroids
|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013MPBu...40..198F
|journal = The Minor Planet Bulletin
|volume = 40
|issue = 4
|pages = 198–203
|issn = 1052-8091
|bibcode = 2013MPBu...40..198F
|access-date= 30 June 2016}}
|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
|journal = Icarus
|volume = 261
|pages = 34–47
|bibcode = 2015Icar..261...34V
|doi = 10.1016/j.icarus.2015.08.007
|arxiv = 1506.00762|s2cid = 53493339 }}
}}
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
- [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center
- [https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=4902+Thessandrus Asteroid 4902 Thessandrus] at the Small Bodies Data Ferret
- {{AstDys|4902}}
- {{JPL small body}}
{{Minor planets navigator|4901 Ó Briain|number=4902|4903 Ichikawa}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Thessandrus}}