9971 Ishihara

File:AnimatedOrbitOf9971Ishihara.gif and Jupiter (outermost)]]

Ishihara is a member of the Flora family, one of the largest families of stony asteroids in the asteroid belt. It orbits the Sun in the inner main-belt at a distance of 1.9–2.4 AU once every 3 years and 3 months (1,177 days). Its orbit has an eccentricity of 0.12 and an inclination of 3° with respect to the ecliptic. It was first identified as {{mp|1991 YC|2}} at Karl Schwarzschild Observatory in 1991, extending the body's observation arc by approximately 2 years prior to its official discovery at Kitami.

This minor planet was named after Takahiro Ishihara (born 1961), an observer of comets, communicator of astronomy, and former president of the astronomical society at Hiroshima (1987–1997). The {{MoMP|9971|official naming citation}} was published by the Minor Planet Center on 6 January 2003 ({{small|M.P.C. 47298}}).

In January 2012, a rotational lightcurve of Ishihara was obtained from photometric observations by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of {{val|6.715|0.0036}} hours with a brightness amplitude of 1.06 in magnitude, which indicates that the body has a non-spheroidal shape ({{small|U=2}}).

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 6.71574 hours ({{small|U=n.a.}}), as well as a spin axis of (42.0°, 76.0°) in ecliptic coordinates (λ, β).

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ishihara measures 4.986 and 5.012 kilometers in diameter and its surface has an albedo of 0.235 and 0.2328, respectively. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, a S-type asteroid and the family's largest member and namesake – and calculates a diameter of 3.74 kilometers with an absolute magnitude of 14.3.

{{reflist|refs=

{{cite web

|type = 2016-11-23 last obs.

|title = JPL Small-Body Database Browser: 9971 Ishihara (1993 HS)

|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2009971

|publisher = Jet Propulsion Laboratory

|access-date = 22 June 2017}}

{{cite book

|title = Dictionary of Minor Planet Names – (9971) Ishihara, Addendum to Fifth Edition: 2003–2005

|last = Schmadel | first = Lutz D.

|publisher = Springer Berlin Heidelberg

|chapter = (9971) Ishihara [2.18, 0.12, 2.7]

|page = 49

|date = 2006

|isbn = 978-3-540-34361-5

|doi = 10.1007/978-3-540-34361-5_391}}

{{cite web

|title = 9971 Ishihara (1993 HS)

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=9971

|access-date = 10 April 2017}}

{{cite web

|title = MPC/MPO/MPS Archive

|work = Minor Planet Center

|url = https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html

|access-date = 10 April 2017}}

{{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

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011ApJ...741...68M

|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

|access-date= 10 April 2017}}

{{cite web

|title = LCDB Data for (9971) Ishihara

|publisher = Asteroid Lightcurve Database (LCDB)

|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=9971

|access-date = 10 April 2017}}

{{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}}

{{cite journal

|first1 = J. |last1 = Durech

|first2 = J. |last2 = Hanus

|first3 = D. |last3 = Oszkiewicz

|first4 = R. |last4 = Vanco

|date = March 2016

|title = Asteroid models from the Lowell photometric database

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016A&A...587A..48D

|journal = Astronomy and Astrophysics

|volume = 587

|page = 6

|bibcode = 2016A&A...587A..48D

|doi = 10.1051/0004-6361/201527573

|arxiv = 1601.02909

|access-date= 10 April 2017}}

{{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

|url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015AJ....150...75W

|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

|access-date= 10 April 2017}}

}}

• [http://www.minorplanet.info/PHP/OneAsteroidInfo.php Lightcurve Database Query] (LCDB), at www.minorplanet.info
• [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] – Geneva Observatory, Raoul Behrend
• [https://www.minorplanetcenter.net/iau/lists/NumberedMPs005001.html Discovery Circumstances: Numbered Minor Planets (5001)-(10000)] – Minor Planet Center
• {{AstDys|9971}}
• {{JPL small body}}

{{Minor planets navigator |(9970) 1992 ST1 |number=9971 |9972 Minoruoda}}

{{Small Solar System bodies}}

{{Authority control}}

{{DEFAULTSORT:Ishihara}}

009971

Category:Discoveries by Kazuro Watanabe

Category:Discoveries by Kin Endate

Category:Named minor planets

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