| 词条 | 1193 Africa |
| 释义 |
| minorplanet = yes | name = 1193 Africa | background = #D6D6D6 | image = | image_size = | caption = | discovery_ref = | discovered = 24 April 1931 | discoverer = C. Jackson | discovery_site = Johannesburg Obs. | mpc_name = (1193) Africa | alt_names = 1931 HB | pronounced = | named_after = Africa {{small|(continent)}}[2] | mp_category = main-belt {{·}}{{small|(middle)}} Eunomia [4][5] | orbit_ref = | epoch = 4 September 2017 (JD 2458000.5) | uncertainty = 0 | observation_arc = 86.20 yr (31,484 days) | aphelion = 2.9728 AU | perihelion = 2.3198 AU | semimajor = 2.6463 AU | eccentricity = 0.1234 | period = 4.30 yr (1,572 days) | mean_anomaly = 9.0113° | mean_motion = {{Deg2DMS|0.2290|sup=ms}} / day | inclination = 14.141° | asc_node = 49.538° | arg_peri = 183.92° | dimensions = {{val|12.220|0.102}} km[7] 13 km {{small|(est. at 0.21)}} | rotation = | albedo = 0.21 {{small|(derived)}} {{val|0.247|0.038}}[7] | spectral_type = S {{small|(derived)}} | abs_magnitude = 11.8 }}1193 Africa, provisional designation {{mp|1931 HB}}, is a stony Eunomian asteroid from the central region of the asteroid belt, approximately 12 kilometers in diameter. It was discovered by South African astronomer Cyril Jackson at Johannesburg Observatory on 24 April 1931.[10] The asteroid was named for the African continent.[2] Orbit and classificationAfrica is a member of the Eunomia family ({{small|502}}), a large group of typically S-type asteroids and the most prominent family in the intermediate main-belt.[4][5] It orbits the Sun at a distance of 2.3–3.0 AU once every 4 years and 4 months (1,572 days). Its orbit has an eccentricity of 0.12 and an inclination of 14° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Johannesburg.[10]Physical characteristicsDiameter and albedoAccording to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Africa measures 12.22 kilometers in diameter and its surface has an albedo of 0.247.[7] Based on a generic magnitude-to-diameter conversion, Africa measures 13 kilometers in diameter, using an absolute magnitude of 11.8 and a standard albedo for Eunomian asteroids of 0.21, derived from 15 Eunomia, the family's largest member and namesake.[17] PhotometryAs of 2017, no rotational lightcurve of Africa has been obtained from photometric observations. The body's rotation period, poles and shape still remain unknown.[19] NamingThis minor planet was named for Africa, the large continent on which Johannesburg is located.[2] The official naming citation was also mentioned in Paul Herget's The Names of the Minor Planets in 1955 ({{small|H 111}}).[2] References1. ^1 2 3 4 {{cite book |title = Dictionary of Minor Planet Names – (1193) Africa |last = Schmadel | first = Lutz D. |publisher = Springer Berlin Heidelberg |page = 100 |date = 2007 |isbn = 978-3-540-00238-3 |doi = 10.1007/978-3-540-29925-7_1194 |chapter = (1193) Africa }} [1][2][3][4][5][6][7]2. ^1 2 {{cite web |title = 1193 Africa (1931 HB) |work = Minor Planet Center |url = http://www.minorplanetcenter.net/db_search/show_object?object_id=1193 |accessdate = 15 August 2017}} 3. ^1 2 3 {{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= 15 August 2017}} 4. ^1 2 {{Cite book |first1 = D. |last1 = Nesvorný |first2 = M. |last2 = Broz |first3 = V. |last3 = Carruba |date = December 2014 |title = Identification and Dynamical Properties of Asteroid Families |journal = Asteroids IV |pages = 297–321 |bibcode = 2015aste.book..297N |doi = 10.2458/azu_uapress_9780816532131-ch016 |arxiv = 1502.01628 |isbn = 9780816532131 }} 5. ^1 2 {{cite web |title = Small Bodies Data Ferret |work = Nesvorny HCM Asteroid Families V3.0 |url = https://sbntools.psi.edu/ferret/PropertySearch/familyForm.action |accessdate = 22 July 2017}} 6. ^1 {{cite web |title = Asteroid Size Estimator |publisher = CNEOS/JPL |url = https://cneos.jpl.nasa.gov/tools/ast_size_est.html |access-date= 2 August 2017}} 7. ^1 {{cite web |title = LCDB Data for (1193) Africa |publisher = Asteroid Lightcurve Database (LCDB) |url = http://www.minorplanet.info/PHP/GenerateALCDEFPage_Local.php?AstInfo=1193%7CAfrica |accessdate = 15 August 2017}} }} External links
5 : Eunomia asteroids|Discoveries by Cyril V. Jackson|Minor planets named for places|Named minor planets|Astronomical objects discovered in 1931 |
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