145534 Jhongda
{{Use dmy dates|date=December 2018}}
{{Infobox planet
| minorplanet = yes
| name = 145534 Jhongda
| background = #D6D6D6
| image =
| image_size =
| caption =
| discovered = 1 April 2006
| discoverer = T.-C. Yang
Q.-Z. Ye
| discovery_site = Lulin Obs.
| mpc_name = (145534) Jhongda
| alt_names = 2006 GJ
| pronounced =
| named_after = {{nowrap|National Central University}}
{{small|(Taiwanese University)}}
| mp_category = main-belt{{·}}({{small|middle}})
Merxia
| epoch = 27 April 2019 (JD 2458600.5)
| uncertainty = 0
| observation_arc = 25.91 yr (9,464 d)
| aphelion = 3.0903 AU
| perihelion = 2.3208 AU
| semimajor = 2.7055 AU
| eccentricity = 0.1422
| period = 4.45 yr (1,625 d)
| mean_anomaly = 262.51°
| mean_motion = {{Deg2DMS|0.2215|sup=ms}} / day
| inclination = 6.2031°
| asc_node = 105.82°
| arg_peri = 189.48°
| mean_diameter = {{val|2.1|ul=km}} {{small|(est. at 0.23)}}
{{val|3.54|u=km}} {{small|(calculated)}}
| rotation = {{val|4.49|0.040|ul=h}}
| albedo = {{val|0.057}} {{small|(assumed)}}
{{val|0.23}} {{small|(family albedo)}}
| spectral_type = C {{small|(assumed)}}
S {{small|(family based)}}
}}
145534 Jhongda, provisional designation {{mp|2006 GJ}}, is an asteroid and member of the stony Merxia family, orbiting in the central region of the asteroid belt, approximately {{convert|2–3|km|mi|abbr=off|sigfig=1|sp=us}} in diameter. It was discovered by Taiwanese astronomers Yang Tingzhang and Ye Quanzhi at the Lulin Observatory on 1 April 2006. The likely elongated asteroid has a rotation period of 4.5 hours. It was named for the Taiwanese National Central University.
Orbit and classification
Jhongda is a member of the Merxia family ({{small|513}}), a large family of stony S-type asteroids named after its parent body 808 Merxia.{{rp|23}} It orbits the Sun in the central main-belt at a distance of 2.3–3.1 AU once every 4 years and 5 months (1,625 days; semi-major axis of 2.71 AU). Its orbit has an eccentricity of 0.14 and an inclination of 6° with respect to the ecliptic. The first precovery was taken by Spacewatch in February 1992, extending the asteroid's observation arc by 14 years prior to its discovery at the Lulin Observatory.
Naming
This minor planet was named after the Taiwanese National Central University, which controls the discovering Lulin Observatory. "Jhongda" is the University's abbreviation in Mandarin Chinese. The official {{MoMP|145534|naming citation}} was published by the Minor Planet Center on 2 April 2007 ({{small|M.P.C. 59389}}).
Physical characteristics
In January 2014, a rotational lightcurve of Jhongda was obtained from photometric observation by astronomers at the Intermediate Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of {{val|4.490|0.040}} hours with a high brightness variation of 0.67 in magnitude ({{small|U=2}}) indicative of an elongated, non-spherical shape. The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 3.54 kilometers with an absolute magnitude of 15.98. Conversely, Jhongda measure only 2.1 kilometers for an albedo of 0.23, which is typical for the stony members of the Merxia family.{{rp|23}}
References
{{reflist|refs=
|type = 2018-01-23 last obs.
|title = JPL Small-Body Database Browser: 145534 Jhongda (2006 GJ)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2145534
|publisher = Jet Propulsion Laboratory
|accessdate = 4 December 2018}}
|title = 145534 Jhongda (2006 GJ)
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=145534
|accessdate = 4 December 2018}}
|title = MPC/MPO/MPS Archive
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html
|accessdate = 4 December 2018}}
|title = Asteroid (145534) Jhongda
|publisher = AstDyS-2, Asteroids – Dynamic Site
|url = https://newton.spacedys.com/astdys/index.php?n=145534&pc=1.1.6
|accessdate = 4 December 2018}}
|title = Asteroid 145534 Jhongda
|work = Small Bodies Data Ferret
|url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=145534+Jhongda
|accessdate = 4 December 2018}}
|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 = 9780816532131
|s2cid = 119280014
}}
|title = Asteroid Size Estimator
|publisher = CNEOS NASA/JPL
|url = https://cneos.jpl.nasa.gov/tools/ast_size_est.html
|accessdate = 4 December 2018}}
|title = LCDB Data for (145534) Jhongda
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=145534%7CJhongda
|accessdate = 4 December 2018}}
|display-authors = 6
|first1 = Chan-Kao |last1 = Chang
|first2 = Wing-Huen |last2 = Ip |author2-link = Ip Wing-huen
|first3 = Hsing-Wen |last3 = Lin
|first4 = Yu-Chi |last4 = Cheng
|first5 = Chow-Choong |last5 = Ngeow
|first6 = Ting-Chang |last6 = Yang
|first7 = Adam |last7 = Waszczak
|first8 = Shrinivas R. |last8 = Kulkarni
|first9 = David |last9 = Levitan
|first10 = Branimir |last10 = Sesar
|first11 = Russ |last11 = Laher
|first12 = Jason |last12 = Surace
|first13 = Thomas. A. |last13 = Prince
|date = August 2015
|title = Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory
|journal = The Astrophysical Journal Supplement Series
|volume = 219
|issue = 2
|page = 19
|bibcode = 2015ApJS..219...27C
|doi = 10.1088/0067-0049/219/2/27
|arxiv = 1506.08493
|s2cid = 17093124 }}
}}
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/NumberedMPs145001.html Discovery Circumstances: Numbered Minor Planets (145001)-(150000)] – Minor Planet Center
- {{AstDys|145534}}
- {{JPL small body}}
{{Minor planets navigator| |number=145534 | }}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:Jhongda}}
Category:Discoveries by Yang Tingzhang