{{Short description|Asteroid}} {{Use dmy dates|date=September 2018}} {{Infobox planet | minorplanet = yes | name = 11277 Ballard | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="MPC-object" /> | discoverer = C. Shoemaker<br />E. Shoemaker | discovery_site = Palomar Obs. | discovered = 8 October 1988 | mpc_name = (11277) Ballard | alt_names = {{mp|1988 TW|2}}{{·}}1995 MG | pronounced = | named_after = Robert Ballard<ref name="MPC-object" /><br />(American oceanographer) | mp_category = main-belt<ref name="MPC-object" /><ref name="jpldata" />{{·}}{{small|(inner)}}<br />Phocaea<ref name="Ferret" /><ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 23 March 2018 (JD 2458200.5) | uncertainty = 0 | observation_arc = 28.73 yr (10,493 d) | aphelion = 2.9757 AU | perihelion = 1.8295 AU | semimajor = 2.4026 AU | eccentricity = 0.2385 | period = 3.72 yr (1,360 d) | mean_anomaly = 22.337° | mean_motion = {{Deg2DMS|0.2647|sup=ms}} / day | inclination = 22.787° | asc_node = 254.59° | arg_peri = 43.574° | mean_diameter = {{val|6.298|0.075|u=km}}<ref name="Ferret" /><ref name="Mainzer-2016" /><ref name="Masiero-2014" /> | rotation = >{{val|10|ul=h}}<ref name="Carbognani-2011a" /> | albedo = {{val|0.222}}<ref name="Mainzer-2016" /><ref name="Masiero-2014" /> | spectral_type = S (assumed)<ref name="lcdb" /> | abs_magnitude = 13.00<ref name="Mainzer-2016" /><ref name="Masiero-2012" /><ref name="WISE" /><br />13.10<ref name="MPC-object" /><ref name="jpldata" /><ref name="lcdb" /><ref name="Nugent-2015" /><br />13.53<ref name="Nugent-2016" /> }}
'''11277 Ballard''' (provisional designation '''{{mp|1988 TW|2}}''') is a Phocaea asteroid from the inner regions of the asteroid belt, approximately {{convert|6.3|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was discovered on 8 October 1988, by American astronomer couple Carolyn and Eugene Shoemaker at the Palomar Observatory in California.<ref name="MPC-object" /> The assumed S-type asteroid has a rotation period of at least 10 hours.<ref name="lcdb" /> It was named for American marine scientist Robert Ballard.<ref name="MPC-object" />
== Orbit and classification == Ballard is a member of the Phocaea family ({{small|701}}).<ref name="Ferret" /> It orbits the Sun in the inner asteroid belt at a distance of 1.83–2.98 AU once every 3 years and 9 months (1,360 days; semi-major axis of 2.4 AU). Its orbit has an eccentricity of 0.24 and an inclination of 23° with respect to the ecliptic.<ref name="jpldata" /> The body's observation arc begins with a precovery taken at Palomar in September 1988, just four weeks prior to its official discovery observation.<ref name="MPC-object" /> Ballard is not a Mars-crosser, since its aphelion is larger than 1.67 AU.<ref name="jpldata" />
== Naming == This minor planet was named after American marine scientist Robert Ballard (born 1942), a professor of oceanography and director of the ''Deep Submergence Laboratory'', who is known for the discovery of the RMS ''Titanic'' and the German battleship Bismarck. The official naming citation was published by the Minor Planet Center on 26 May 2002 ({{small|M.P.C. 45748}}).<ref name="MPC-Circulars-Archive" />
== Physical characteristics == Ballard is an assumed, stony S-type asteroid,<ref name="lcdb" /> in line with the Phocaea family's overall spectral type.<ref name="Nesvorny-2014" />{{rp|23}}
=== Rotation period === In July 2010, a rotational lightcurve of Ballard was obtained from two nights of photometric observations in the R-band by Italian astronomer Albino Carbognani at the OAVdA Observatory {{Obscode|B04}} in Italy. Lightcurve analysis gave a tentative rotation period of at least 10 hours with a brightness amplitude of more than 0.25 magnitude ({{small|U=2-}}).<ref name="Carbognani-2011a" />
=== Diameter and albedo === According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ballard measures between 5.65 and 6.445 kilometers in diameter and its surface has an albedo between 0.19 and 0.289.<ref name="Ferret" /><ref name="lcdb" /><ref name="Mainzer-2016" /><ref name="Masiero-2014" /><ref name="Masiero-2012" /><ref name="WISE" /><ref name="Nugent-2015" /><ref name="Nugent-2016" />
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.23 – derived from the family's largest member, 25 Phocaea – and calculates a diameter of 6.65 kilometers based on an absolute magnitude of 13.1.<ref name="lcdb" />
== References == {{reflist|30em|refs=
<ref name="jpldata">{{cite web |type = 2017-06-05 last obs. |title = JPL Small-Body Database Browser: 11277 Ballard (1988 TW2) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2011277 |publisher = Jet Propulsion Laboratory |accessdate = 25 September 2018}}</ref>
<ref name="MPC-object">{{cite web |title = 11277 Ballard (1988 TW2) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=11277 |accessdate = 25 September 2018}}</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 |accessdate = 25 September 2018}}</ref>
<ref name="Masiero-2014">{{cite journal |display-authors = 6 |first1 = Joseph R. |last1 = Masiero |first2 = T. |last2 = Grav |first3 = A. K. |last3 = Mainzer |first4 = C. R. |last4 = Nugent |first5 = J. M. |last5 = Bauer |first6 = R. |last6 = Stevenson |first7 = S. |last7 = Sonnett |date = August 2014 |title = Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos |journal = The Astrophysical Journal |volume = 791 |issue = 2 |page = 11 |bibcode = 2014ApJ...791..121M |doi = 10.1088/0004-637X/791/2/121 |arxiv = 1406.6645|s2cid = 119293330 }}</ref>
<ref name="Ferret">{{cite web |title = Asteroid 11277 Ballard |work = Small Bodies Data Ferret |url = https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=11277+Ballard |accessdate = 25 September 2018}}</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|s2cid = 119280014 }}</ref>
<ref name="lcdb">{{cite LCDB|number = 11277 |accessdate = 25 September 2018}}</ref>
<ref name="Masiero-2012">{{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 = C. |last6 = Nugent |first7 = M. S. |last7 = Cabrera |date = November 2012 |title = Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids |journal = The Astrophysical Journal Letters |volume = 759 |issue = 1 |page = 5 |bibcode = 2012ApJ...759L...8M |doi = 10.1088/2041-8205/759/1/L8 |arxiv = 1209.5794|s2cid = 46350317 }}</ref>
<ref name="Nugent-2015">{{cite journal |display-authors = 6 |first1 = C. R. |last1 = Nugent |first2 = A. |last2 = Mainzer |first3 = J. |last3 = Masiero |first4 = J. |last4 = Bauer |first5 = R. M. |last5 = Cutri |first6 = T. |last6 = Grav |first7 = E. |last7 = Kramer |first8 = S. |last8 = Sonnett |first9 = R. |last9 = Stevenson |first10 = E. L. |last10 = Wright |date = December 2015 |title = NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos |journal = The Astrophysical Journal |volume = 814 |issue = 2 |page = 13 |bibcode = 2015ApJ...814..117N |doi = 10.1088/0004-637X/814/2/117 |arxiv = 1509.02522|s2cid = 9341381 }}</ref>
<ref name="Mainzer-2016">{{cite journal |display-authors = 6 |first1 = A. K. |last1 = Mainzer |first2 = J. M. |last2 = Bauer |first3 = R. M. |last3 = Cutri |first4 = T. |last4 = Grav |first5 = E. A. |last5 = Kramer |first6 = J. R. |last6 = Masiero |first7 = C. R. |last7 = Nugent |first8 = S. M. |last8 = Sonnett |first9 = R. A. |last9 = Stevenson |first10 = E. L. |last10 = Wright |date = June 2016 |title = NEOWISE Diameters and Albedos V1.0 |url = https://sbnarchive.psi.edu/pds3/non_mission/EAR_A_COMPIL_5_NEOWISEDIAM_V1_0/data/neowise_mainbelt.tab |journal = NASA Planetary Data System |pages = EAR-A-COMPIL-5-NEOWISEDIAM-V1.0 |bibcode = 2016PDSS..247.....M |access-date= 25 September 2018}}</ref>
<ref name="Nugent-2016">{{cite journal |display-authors = 6 |first1 = C. R. |last1 = Nugent |first2 = A. |last2 = Mainzer |first3 = J. |last3 = Bauer |first4 = R. M. |last4 = Cutri |first5 = E. A. |last5 = Kramer |first6 = T. |last6 = Grav |first7 = J. |last7 = Masiero |first8 = S. |last8 = Sonnett |first9 = E. L. |last9 = Wright |date = September 2016 |title = NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos |journal = The Astronomical Journal |volume = 152 |issue = 3 |page = 12 |bibcode = 2016AJ....152...63N |doi = 10.3847/0004-6256/152/3/63 |arxiv = 1606.08923 |doi-access = free }}</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 |s2cid = 35447010 }} ([http://iopscience.iop.org/0004-637X/741/2/68/fulltext/apj398969t1_mrt.txt catalog])</ref>
<ref name="Carbognani-2011a">{{Cite journal |author = Carbognani, Albino |date = January 2011 |title = Lightcurves and Periods of Eighteen NEAs and MBAs |journal = The Minor Planet Bulletin |volume = 38 |issue = 1 |pages = 57–63 |issn = 1052-8091 |bibcode = 2011MPBu...38...57C}}</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 * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs010001.html Discovery Circumstances: Numbered Minor Planets (10001)-(15000)] – Minor Planet Center * {{AstDys|11277}} * {{JPL small body}}
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{{DEFAULTSORT:Ballard}} 011277 Category:Discoveries by Carolyn S. Shoemaker Category:Discoveries by Eugene Merle Shoemaker Category:Named minor planets 19881008