{{Short description|Stony Agnia asteroid}} {{Use dmy dates|date=March 2018}} {{Infobox planet | minorplanet = yes | name = 7803 Adachi | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="MPC-object" /> | discovered = 4 March 1997 | discoverer = T. Kobayashi | discovery_site = Ōizumi Obs. | mpc_name = (7803) Adachi | alt_names = {{mp|1997 EW|2}}{{·}}{{mp|1973 AA|3}}<br />{{mp|1976 UY|17}}{{·}}{{mp|1978 EM|1}}<br />{{mp|1992 CF|2}} | named_after = Makoto Adachi<ref name="MPC-object" /><br />{{small|(amateur astronomer)}} | mp_category = main-belt<ref name="MPC-object" /><ref name="jpldata" />{{·}}{{small|(middle)}}<br />Agnia<ref name="Ferret" /> | orbit_ref = <ref name="jpldata" /> | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 63.96 yr (23,363 d) | aphelion = 2.9253 AU | perihelion = 2.6459 AU | semimajor = 2.7856 AU | eccentricity = 0.0502 | period = 4.65 yr (1,698 d) | mean_anomaly = 239.11° | mean_motion = {{Deg2DMS|0.2120|sup=ms}} / day | inclination = 4.9969° | asc_node = 110.63° | arg_peri = 8.8759° | dimensions = {{val|6.359|0.129|ul=km}}<ref name="WISE" /><ref name="Masiero-2011" /><br />{{val|10.31|u=km}} {{small|(calculated)}}<ref name="lcdb" /> | rotation = {{val|5.1966|0.0082|ul=h}}<ref name="Waszczak-2016" /> | albedo = 0.057 {{small|(assumed)}}<ref name="lcdb" /><br />{{val|0.251|0.055}}<ref name="WISE" /><ref name="Masiero-2011" /> | spectral_type = S<ref name="Veres-2015" />{{·}}C {{small|(generic)}}<ref name="lcdb" /> | abs_magnitude = 13.1<ref name="WISE" />{{·}}{{val|13.212|0.005}} {{small|(R)}}<ref name="Waszczak-2016" />{{·}}13.3<ref name="jpldata" />{{·}}{{val|13.65|0.27}}<ref name="Veres-2015" />{{·}}13.66<ref name="lcdb" /> }}
'''7803 Adachi''', provisional designation {{mp|1997 EW|2}}, is a stony Agnia asteroid from the middle region of the asteroid belt, approximately {{convert|6.4|km|mi|abbr=off|sigfig=1|sp=us}} in diameter. The asteroid was discovered on 4 March 1997, by Japanese amateur astronomer Takao Kobayashi at the Ōizumi Observatory in central Japan. It was named for Japanese amateur astronomer Makoto Adachi.<ref name="MPC-object" /> The S-type asteroid has a rotation period of 5.2 hours.<ref name="lcdb" />
== Orbit and classification ==
''Adachi'' is a member of the Agnia family ({{small|514}}),<ref name="Ferret" /><ref name="Sunshine-2004" /> a very large family of stony asteroids with more than 2000 known members.<ref name="Nesvorny-2014" /> They most likely formed from the breakup of a basalt object, which in turn was spawned from a larger parent body that underwent igneous differentiation.<ref name="Sunshine-2004" /> The family's parent body and namesake is the asteroid 847 Agnia.<ref name="Nesvorny-2014" />
It orbits the Sun in the central asteroid belt at a distance of 2.6–2.9 AU once every 4 years and 8 months (1,698 days; semi-major axis of 2.79 AU). Its orbit has an eccentricity of 0.05 and an inclination of 5° with respect to the ecliptic.<ref name="jpldata" /> The first precovery was taken at the U.S. Palomar Observatory in 1953, extending the asteroid's observation arc by 44 years prior to it discovery.<ref name="MPC-object" />
== Physical characteristics ==
''Adachi'' has been characterized as a stony S-type asteroid by Pan-STARRS photometric survey,<ref name="Veres-2015" /> which agrees with the Agnia family's overall spectral type.<ref name="Nesvorny-2014" /> {{rp|23}}
=== Diameter and albedo ===
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Adachi'' measures 6.359 kilometers in diameter and its surface has an albedo between 0.251 and 0.2513.<ref name="WISE" /><ref name="Masiero-2011" /> The ''Collaborative Asteroid Lightcurve Link'' assumes a generic, carbonaceous albedo of 0.057 for all minor planets with a semi-major axis of more than 2.7 AU, and consequently calculates a larger diameter of 10.31 kilometers using an absolute magnitude of 13.66.<ref name="lcdb" />
=== Rotation period ===
In August 2013, a rotational lightcurve of ''Adachi'' was obtained through photometric observations at the Palomar Transient Factory in California. It showed a period of {{val|5.1966}} hours with a brightness variation of 0.31 magnitude ({{small|U=2}}).<ref name="Waszczak-2016" />
== Naming ==
This minor planet was named after Makoto Adachi (born 1953), Japanese amateur astronomer and elementary school teacher from Kyoto. He is the director of the ''Oriental Astronomical Association'' and a long-time direct observer of the Solar System's planets, especially Jupiter.<ref name="MPC-object" /> The approved naming citation was published by the Minor Planet Center on 6 August 2003 {{small|(M.P.C. 49279)}}.<ref name="MPC-Circulars-Archive" />
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2017-09-27 last obs. |title = JPL Small-Body Database Browser: 7803 Adachi (1997 EW2) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2007803 |publisher = Jet Propulsion Laboratory |access-date = 8 March 2018}}</ref>
<ref name="MPC-object">{{cite web |title = 7803 Adachi (1997 EW2) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=7803 |access-date = 28 April 2016}}</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 = 28 April 2016}}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 7803 Adachi – Nesvorny HCM Asteroid Families V3.0 |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=7803+Adachi#Asteroid%207803%20AdachiEAR-A-VARGBDET-5-NESVORNYFAM-V3.0 |access-date = 27 October 2019}}</ref>
<ref name="Nesvorny-2014">{{Cite book |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 }}</ref>
<ref name="Sunshine-2004">{{Cite journal |first1 = Jessica M. |last1 = Sunshine |first2 = Schelte J. |last2 = Bus |first3 = Timothy J. |last3 = McCoy |first4 = Thomas H. |last4 = Burbine |first5 = Catherine M. |last5 = Corrigan |first6 = Richard P. |last6 = Binzel |date = August 2004 |title = High-calcium pyroxene as an indicator of igneous differentiation in asteroids and meteorites |url = https://www.researchgate.net/publication/228936637 |journal = Meteoritics and Planetary Science |volume = 39 |issue = 8 |pages = 1343–1357 |bibcode = 2004M&PS...39.1343S |doi = 10.1111/j.1945-5100.2004.tb00950.x |access-date= 8 March 2018 }}</ref>
<ref name="lcdb">{{cite LCDB|number = 7803 |access-date = 28 April 2016}}</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 }}</ref>
<ref name="Waszczak-2016">{{cite journal |display-authors = 6 |first1 = Adam |last1 = Waszczak |first2 = Chan-Kao |last2 = Chang |first3 = Eran O. |last3 = Ofek |first4 = Russ |last4 = Laher |first5 = Frank |last5 = Masci |first6 = David |last6 = Levitan |first7 = Jason |last7 = Surace |first8 = Yu-Chi |last8 = Cheng |first9 = Wing-Huen |last9 = Ip |first10 = Daisuke |last10 = Kinoshita |first11 = George |last11 = Helou |first12 = Thomas A. |last12 = Prince |first13 = Shrinivas |last13 = Kulkarni |date = September 2015 |title = Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry |journal = The Astronomical Journal |volume = 150 |issue = 3 |page = 35 |bibcode = 2015AJ....150...75W |doi = 10.1088/0004-6256/150/3/75 |arxiv = 1504.04041 }}</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 |journal = Icarus |volume = 261 |pages = 34–47 |bibcode = 2015Icar..261...34V |doi = 10.1016/j.icarus.2015.08.007 |arxiv = 1506.00762 }}</ref>
<ref name="Masiero-2011">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = A. K. |last2 = Mainzer |first3 = T. |last3 = Grav |first4 = J. M. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = J. |last6 = Dailey |first7 = P. R. M. |last7 = Eisenhardt |first8 = R. S. |last8 = McMillan |first9 = T. B. |last9 = Spahr |first10 = M. F. |last10 = Skrutskie |first11 = D. |last11 = Tholen |first12 = R. G. |last12 = Walker |first13 = E. L. |last13 = Wright |first14 = E. |last14 = DeBaun |first15 = D. |last15 = Elsbury |first16 = T. IV |last16 = Gautier |first17 = S. |last17 = Gomillion |first18 = A. |last18 = Wilkins |date = November 2011 |title = Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters |journal = The Astrophysical Journal |volume = 741 |issue = 2 |page = 20 |bibcode = 2011ApJ...741...68M |doi = 10.1088/0004-637X/741/2/68 |arxiv = 1109.4096 }}</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 * [https://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center * {{AstDys|7803}} * {{JPL small body}}
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{{DEFAULTSORT:Adachi}} 007803 Category:Discoveries by Takao Kobayashi Category:Named minor planets 19970304