1355 Magoeba

{{Short description|Hungaria asteroid and a suspected contact-binary}} {{Use dmy dates|date=October 2019}} {{Infobox planet | minorplanet = yes | name = 1355 Magoeba | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = <ref name="jpldata" /> | discovered = 30 April 1935 | discoverer = C. Jackson | discovery_site = Johannesburg Obs. | mpc_name = (1355) Magoeba | alt_names = 1935 HE | named_after = Magoeba {{small|(South African chief)}}<ref name="springer" /> | mp_category = main-belt{{·}}Hungaria<ref name="MPC-Magoeba" /><ref name="lcdb" /> | orbit_ref = <ref name="jpldata" /> | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 81.71 yr (29,843 days) | aphelion = 1.9363 AU | perihelion = 1.7707 AU | semimajor = 1.8535 AU | eccentricity = 0.0447 | period = 2.52 yr (922 days) | mean_anomaly = 245.86° | mean_motion = {{Deg2DMS|0.3906|sup=ms}} / day | inclination = 22.827° | asc_node = 225.25° | arg_peri = 340.40° | dimensions = {{val|4.276|0.170}} km<ref name="Masiero-2014" /> {{val|4.828|0.094}} km<ref name="WISE" /> 5.96 km {{small|(calculated)}}<ref name="lcdb" /> | rotation = {{val|2.9712|0.0003}} h<ref name="Warner-2015e" /> {{val|2.972|0.002}} h<ref name="Warner-2013o" /> {{val|2.975|0.002}} h<ref name="Warner-2013o" /> {{val|5.946|0.005}} h<ref name="Warner-2010e" /> {{val|5.99|0.05}} h<ref name="Warner-2011r" />{{efn|name=lightcurve-plot-2011}} {{val|31.65|0.05}} h<ref name="Warner-2010e" /> {{val|32.9|0.1}} h<ref name="Warner-2007a" /> | albedo = {{val|0.267|0.095}}<ref name="Gil-Hutton-2007" /> 0.3 {{small|(assumed)}}<ref name="lcdb" /> {{val|0.4663|0.0824}}<ref name="WISE" /> {{val|0.582|0.049}}<ref name="Masiero-2014" /> | spectral_type = Tholen = X<ref name="jpldata" />{{·}}M<ref name="Fornasier-2011a" />{{·}}E<ref name="WISE" />{{·}}X<ref name="lcdb" /> B–V = 0.713<ref name="jpldata" /> U–B = 0.255<ref name="jpldata" /> | abs_magnitude = {{val|13.02|0.22}}<ref name="Veres-2015" />{{·}}13.05<ref name="jpldata" /><ref name="lcdb" /><ref name="WISE" /> }}

'''1355 Magoeba''', provisional designation {{mp|1935 HE}}, is a Hungaria asteroid and a suspected contact-binary from the innermost regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 30 April 1935, by English-born, South African astronomer Cyril Jackson at the Johannesburg Observatory in South Africa.<ref name="MPC-Magoeba" /> The asteroid is named for Magoeba, a tribal chief in the South African Transvaal Province.<ref name="springer" />

== Orbit and classification ==

''Magoeba'' is a member of the Hungaria family, which forms the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the inner main-belt at a distance of 1.8–1.9 AU once every 2 years and 6 months (922 days). Its orbit has an eccentricity of 0.04 and an inclination of 23° with respect to the ecliptic.<ref name="jpldata" /> The first precovery was taken at Nice Observatory just 3 day prior to its official discovery. The body's observation arc begins at Johannesburg the night after its discovery observation.<ref name="MPC-Magoeba" />

== Physical characteristics == === Lightcurves ===

Between 2006 and 2014, several rotational lightcurves of ''Magoeba'' were obtained by American astronomer Brian Warner at the CS3–Palmer Divide Station ({{small|U82}}) in California. Lightcurve analysis of the photometric observations taken during the asteroid's 2014-apparition gave a rotation period of 2.971 hours with a brightness variation of 0.09 magnitude ({{small|U=3}}).<ref name="Warner-2015e" />{{efn|name=LCDB-lightcure-plots}}

Previously derived periods varied strongly (5.99 and 31.65 hours) with alternative period solutions ({{small|U=2-/2/2}}).<ref name="Warner-2010e" /><ref name="Warner-2011r" /><ref name="Warner-2007a" />{{efn|name=lightcurve-plot-2011}} The Observation were taken at the Palmer Divide Observatory ({{small|716}}) in Colorado ''(see video in {{section link||External links}})''. It is now suspected that this discrepancy might be caused by the presence of an asteroid moon that orbits ''Magoeba'' with a period of 15.05 hours.<ref name="Warner-2015e" />

=== Diameter and albedo ===

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ''Magoeba'' measures 4.276 and 4.828 kilometers in diameter, and its surface has an albedo of 0.582 and 0.466, respectively,<ref name="Masiero-2014" /><ref name="WISE" /> while a polarimetric study of Hungaria asteroids found a lower albedo of 0.267.<ref name="Gil-Hutton-2007" /> The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between 0.4 and 0.2, corresponding to the Hungaria asteroids both as family and orbital group – and calculates a diameter of 5.96 kilometers with an absolute magnitude of 13.05.<ref name="lcdb" />

=== Spectral type ===

In the Tholen taxonomy, ''Magoeba'' is an X-type asteroid, which can be further divided into the bright E, the metallic M and the carbonaceous P classes, with similar spectra but very different inferred mineralogies.<ref name="Fornasier-2011a" /> It has both been classified as an E-type asteroid by the WISE/NEOWISE mission, and as a M-type asteroid by a dedicated spectroscopic survey at the Argentinian Lencito Complex, respectively.<ref name="WISE" /><ref name="Fornasier-2011a" />

== Naming ==

This minor planet was named for Magoeba, a native chief of the North Transvaal in South Africa.<ref name="springer" /> The official {{MoMP|1355|naming citation}} was published by the Minor Planet Center in April 1953 ({{small|M.P.C. 908}}).<ref name="DoMP-Circular-dates" />

== Notes == {{notelist|refs=

{{efn|name=LCDB-lightcure-plots|1=Light-curve plots of (1355) Magoeba from the [http://www.planetarysciences.org/plots/BDW/1355_MAGOEBA_2013-05-27.PNG 2013-observation] and from the [http://www.planetarysciences.org/plots/BDW/1355_MAGOEBA_2014-09-02.PNG 2014-observation], published by the Center for Solar System Studies [http://planetarysciences.org/lightcurves.html (CS3)] in Landers, California.}}

{{efn|name=lightcurve-plot-2011|1={{usurped|1=[https://web.archive.org/web/20170322020725/http://www.minorplanetobserver.com/pdolc/A1355_2011.HTM Lightcurve plot]}} of (1355) Magoeba, Palmer Divide Observatory, B. D. Warner (2011)}}

}}

== References == <references>

<ref name="jpldata">{{cite web |type = 2017-01-09 last obs. |title = JPL Small-Body Database Browser: 1355 Magoeba (1935 HE) |url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001355 |publisher = Jet Propulsion Laboratory |accessdate = 25 July 2017}}</ref>

<ref name="springer">{{cite book |title = Dictionary of Minor Planet Names – (1355) Magoeba |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 110 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1356 |chapter = (1355) Magoeba }}</ref>

<ref name="MPC-Magoeba">{{cite web |title = 1355 Magoeba (1935 HE) |work = Minor Planet Center |url = https://www.minorplanetcenter.net/db_search/show_object?object_id=1355 |accessdate = 13 January 2017}}</ref>

<ref name="DoMP-Circular-dates">{{cite book |title = Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) |chapter = Appendix – Publication Dates of the MPCs |last = Schmadel |first=Lutz D. |publisher = Springer Berlin Heidelberg |page = 221 |isbn = 978-3-642-01964-7 |doi = 10.1007/978-3-642-01965-4}}</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 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M |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 |access-date= 13 January 2017}}</ref>

<ref name="lcdb">{{cite LCDB|number = 1355 |accessdate = 13 January 2017}}</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="Warner-2007a">{{Cite journal |author = Warner, Brian D. |date = March 2007 |title = Asteroid Lightcurve Analysis at the Palmer Divide Observatory - June-September 2006 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2007MPBu...34....8W |journal = The Minor Planet Bulletin |volume = 34 |issue = 1 |pages = 8–10 |issn = 1052-8091 |bibcode = 2007MPBu...34....8W |access-date= 13 January 2017}}</ref>

<ref name="Warner-2010e">{{Cite journal |author = Warner, Brian D. |date = April 2010 |title = Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 September–December |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2010MPBu...37...57W |journal = The Minor Planet Bulletin |volume = 37 |issue = 2 |pages = 57–64 |issn = 1052-8091 |bibcode = 2010MPBu...37...57W |access-date= 13 January 2017}}</ref>

<ref name="Warner-2011r">{{Cite journal |author = Warner, Brian D. |date = October 2011 |title = Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 March - July |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011MPBu...38..190W |journal = The Minor Planet Bulletin |volume = 38 |issue = 4 |pages = 190–195 |issn = 1052-8091 |bibcode = 2011MPBu...38..190W |access-date= 13 January 2017}}</ref>

<ref name="Warner-2013o">{{Cite journal |author = Warner, Brian D. |date = October 2013 |title = Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 May–June |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013MPBu...40..208W |journal = The Minor Planet Bulletin |volume = 40 |issue = 4 |pages = 208–212 |issn = 1052-8091 |bibcode = 2013MPBu...40..208W |access-date= 13 January 2017}}</ref>

<ref name="Warner-2015e">{{Cite journal |author = Warner, Brian D. |date = January 2015 |title = A Sextet of Main-belt Binary Asteroid Candidates |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015MPBu...42...60W |journal = The Minor Planet Bulletin |volume = 42 |issue = 1 |pages = 60–66 |issn = 1052-8091 |bibcode = 2015MPBu...42...60W |access-date= 13 January 2017}}</ref>

<ref name="Gil-Hutton-2007">{{Cite journal |first1 = R. |last1 = Gil-Hutton |first2 = D. |last2 = Lazzaro |first3 = P. |last3 = Benavidez |date = June 2007 |title = Polarimetric observations of Hungaria asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2007A&A...468.1109G |journal = Astronomy and Astrophysics |volume = 468 |issue = 3 |pages = 1109–1114 |bibcode = 2007A&A...468.1109G |doi = 10.1051/0004-6361:20077178 |access-date= 13 January 2017|doi-access= free |hdl= 11336/213855 |hdl-access= free }}</ref>

<ref name="Fornasier-2011a">{{Cite journal |first1 = S. |last1 = Fornasier |first2 = B. E. |last2 = Clark |first3 = E. |last3 = Dotto |date = July 2011 |title = Spectroscopic survey of X-type asteroids |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011Icar..214..131F |journal = Icarus |volume = 214 |issue = 1 |pages = 131–146 |bibcode = 2011Icar..214..131F |doi = 10.1016/j.icarus.2011.04.022 |arxiv = 1105.3380 |access-date= 13 January 2017}}</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 |url = http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V |journal = Icarus |volume = 261 |pages = 34–47 |bibcode = 2015Icar..261...34V |doi = 10.1016/j.icarus.2015.08.007 |arxiv = 1506.00762 |access-date= 13 January 2017}}</ref>

</references>

== External links == * {{YouTube|id=3Kn3s98KRYw|title=The Palmer Divide Observatory: ''Tour given by Brian Warner''}} {{small|(time 4:03 min.)}} * [https://web.archive.org/web/20150924071119/http://www.people.fas.harvard.edu/~cuk/papers/hungaria.pdf Dynamical evolution of the Hungaria asteroids] * [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 * [http://obswww.unige.ch/~behrend/page_cou.html Asteroids and comets rotation curves, CdR] – Observatoire de Genève, Raoul Behrend * [https://www.minorplanetcenter.net/iau/lists/NumberedMPs000001.html Discovery Circumstances: Numbered Minor Planets (1)-(5000)] – Minor Planet Center * {{AstDys|1355}} * {{JPL small body}}

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{{DEFAULTSORT:Magoeba}} 001355 Category:Discoveries by Cyril Jackson (astronomer) Category:Named minor planets 001355 19350430 001355