849 Ara

Last updated

849 Ara
000849-asteroid shape model (849) Ara.png
Modelled shape of Ara from its lightcurve
Discovery [1]
Discovered by S. Belyavskyj
Discovery site Simeiz Obs.
Discovery date9 February 1912
Designations
(849) Ara
Pronunciation /ˈɛərə/ [2]
Named after
American Relief Administration [3]
A912 CD ·1935 FU
1960 WN ·A915 UB
1912 NY ·1915 Σai
Orbital characteristics [4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc 100.58 yr (36,737 d)
Aphelion 3.7783 AU
Perihelion 2.5141 AU
3.1462 AU
Eccentricity 0.2009
5.58 yr (2,038 d)
323.29°
0° 10m 35.76s / day
Inclination 19.530°
228.37°
63.293°
TJupiter 3.0900
Physical characteristics
Dimensions97.5  km × 70.7  km [6]
Mean diameter
80.756±1.127 km [7]
4.116 h [8] [9]
(223.0°, −41.0°) 11) [10]
0.126±0.040 [7]
8.2 [1] [4]

    849 Ara (prov. designation: A912 CDor1912 NY) is a large, metallic background asteroid, approximately 80 kilometers (50 miles) in diameter, that is located in the outer region of the asteroid belt. It was discovered on 9 February 1912, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. [1] The M-type asteroid has a short rotation period of 4.1 hours and is likely elongated in shape. It was named after the American Relief Administration (ARA) for the help given during the Russian famine of 1921–22. [3]

    Contents

    Orbit and classification

    Ara is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. [5] [6] It orbits the Sun in the outer asteroid belt at a distance of 2.5–3.8  AU once every 5 years and 7 months (2,038 days; semi-major axis of 3.15 AU). Its orbit has an eccentricity of 0.20 and an inclination of 20° with respect to the ecliptic. [4] In addition, Ara has a low Jupiter tisserand of 3.09, just above the defined threshold of 3.0 which is used to distinguish asteroids from the Jupiter-family comets. [4] The body's observation arc begins at the Collegio Romano Observatory ( 531 ) in Italy on 3 July 1919, more than 6 years after its official discovery observation at Simeiz. [1]

    Naming

    This minor planet was named after American Relief Administration (ARA), in appreciation of the help it gave during the Russian famine of 1921–22. Headed by Herbert Hoover, ARA was a relief mission after World War I to Europe which also included post-revolutionary Russia later on. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ( H 83 ). [3]

    Physical characteristics

    In the Tholen classification as well as in the lesser known taxonomic method by Howell, Ara is a metallic M-type asteroid. [4] [6] [11] This spectral type translates into the X-type in more modern asteroid taxonomic systems. In 2018 and 2019, a study using photometry from the Korea Microlensing Telescope Network and the South African Astronomical Observatory, grouped Ara into the X-type category based on the Bus–DeMeo classification. [12] [14] [15]

    Rotation period and pole

    Lightcurve-based 3D-model of Ara 849Ara (Lightcurve Inversion).png
    Lightcurve-based 3D-model of Ara

    In June 1981, a rotational lightcurve of Ara was obtained from photometric observations by Alan Harris. Lightcurve analysis gave a rotation period of 4.116 hours with a brightness variation of 0.34 magnitude, indicative of an elongated shape ( U=3 ). [8] Numerous observations have since confirmed this period. [15] This includes Laurent Bernasconi 4.1165±0.0007 h (2004) and 4.123±0.007 h (2006), [9] Davide Gandolfi 4.117±0.001 h (2006), [13] Adam Marciniak 4.116±0.001 h (2009), [16] Maurice Audejean 4.1176±0.0007 h (2010), [9] and Richard E. Schmidt 4.1168±0.0025 h (2017). [17] In 2017, a modeled lightcurve gave a concurring sidereal period of 4.116391±0.000002 hours as well as a spin axis of (223.0°, −41.0°) in ecliptic coordinates (λ, β). [10]

    Diameter and albedo

    According to the surveys carried out by the Japanese Akari satellite, the Infrared Astronomical Satellite IRAS, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), Ara measures (59.92±1.09), (61.82±3.3) and (80.756±1.127) kilometers in diameter and its surface has an albedo of (0.287±0.013), (0.2660±0.031) and (0.126±0.040), respectively. [7] [18] [19] Alternative mean-diameters published by the WISE team include (74.00±2.89  km ) and (84.417±2.447 km) with corresponding albedos of (0.186±0.023) and (0.1155±0.0163). [6] [15]

    In 2009 and 2015, several asteroid occultations of Ara were observed. The two best-rated observations from January 2009 and April 2015 and August 2008, gave a best-fit ellipse dimension of (97.5 km × 70.7 km) and (98.0 km × 98.0 km), respectively. [6] These timed observations are taken when the asteroid passes in front of a distant star. The Collaborative Asteroid Lightcurve Link adopts Petr Pravec's revised WISE albedo of 0.1149 and takes a diameter of 84.61 kilometers based on an absolute magnitude of 8.33, [15] while Josef Ďurech calculates a diameter of 76±14 km by combining lightcurve inversion models with asteroid occultation silhouettes. [20]

    Related Research Articles

    <span class="mw-page-title-main">1036 Ganymed</span>

    1036 Ganymed, provisional designation 1924 TD, is a stony asteroid on a highly eccentric orbit, classified as a near-Earth object of the Amor group. It was discovered by German astronomer Walter Baade at the Bergedorf Observatory in Hamburg on 23 October 1924, and named after Ganymede from Greek mythology. With a diameter of approximately 35 kilometers, Ganymed is the largest of all near-Earth objects but does not cross Earth's orbit. The S-type asteroid has a rotation period of 10.3 hours. In October 2024, it is predicted to approach Earth at a distance of 56,000,000 km; 35,000,000 mi (0.374097 AU).

    <span class="mw-page-title-main">63 Ausonia</span> Main-belt asteroid

    Ausonia is a stony Vestian asteroid from the inner region of the asteroid belt, approximately 100 kilometers in diameter. It was discovered by Italian astronomer Annibale de Gasparis on 10 February 1861, from the Astronomical Observatory of Capodimonte, in Naples, Italy. The initial choice of name for the asteroid was "Italia", after Italy, but this was modified to Ausonia, an ancient classical name for the Italian region.

    <span class="mw-page-title-main">71 Niobe</span> Main-belt asteroid

    Niobe is a stony Gallia asteroid and relatively slow rotator from the central regions of the asteroid belt, approximately 90 kilometers in diameter. It was discovered by the German astronomer Robert Luther on 13 August 1861, and named after Niobe, a character in Greek mythology. In 1861, the brightness of this asteroid was shown to vary by astronomer Friedrich Tietjen.

    <span class="mw-page-title-main">144 Vibilia</span> Main-belt asteroid

    144 Vibilia is a carbonaceous asteroid from the central region of the asteroid belt, approximately 140 kilometers in diameter. It was discovered on 3 June 1875, by German–American astronomer Christian Peters at Litchfield Observatory of the Hamilton College in Clinton, New York, United States. Peters named it after Vibilia, the Roman goddess of traveling, because he had recently returned from a journey across the world to observe the transit of Venus. Peters also discovered 145 Adeona on the same night. The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955.

    <span class="mw-page-title-main">251 Sophia</span> Main-belt asteroid

    251 Sophia is a stony background asteroid from the outer regions of the asteroid belt. It was discovered on 4 October 1885, by astronomer Johann Palisa at the Vienna Observatory in Austria. The S-type asteroid (S/L) has a rotation period of 20.2 hours and measures approximately 28 kilometers in diameter. It was named after Sophia von Seeliger, wife of German astronomer Hugo von Seeliger (1849–1924).

    <span class="mw-page-title-main">462 Eriphyla</span> Main-belt asteroid

    462 Eriphyla is a Koronian asteroid from the outer regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 22 October 1900. The stony S-type asteroid has a rotation period of 8.7 hours and measures approximately 35 kilometers in diameter. It was named after Eriphyle, from Greek mythology.

    <span class="mw-page-title-main">512 Taurinensis</span> Mars-crossing asteroid

    Taurinensis, provisional designation 1903 LV, is a stony asteroid and large Mars-crosser on an eccentric orbit from the inner regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 23 June 1903, by astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named after the Italian city of Turin. It is the 4th-largest Mars-crossing asteroid.

    <span class="mw-page-title-main">732 Tjilaki</span>

    732 Tjilaki is a dark background asteroid, approximately 36 kilometers in diameter, located in the inner region of the asteroid belt. It was discovered by German astronomer Adam Massinger at the Heidelberg Observatory on 15 April 1912, and later named after the Cilaki (Tjilaki) river in Indonesia. The dark D-type asteroid has a rotation period of 12.3 hours. It was an early candidate to be visited by the Rosetta spacecraft which eventually rendezvoused comet 67P/Churyumov–Gerasimenko.

    779 Nina is a large background asteroid, approximately 80 kilometers in diameter, located in the central region of the asteroid belt. It was discovered on 25 January 1914, by Russian astronomer Grigory Neujmin(1886-1946) at the Simeiz Observatory on the Crimean peninsula. The metallic X-type asteroid with an intermediate albedo has a rotation period of 11.2 hours. It was named after the discoverer's sister, Nina Neujmina (Tsentilovich) (1889–1971).

    <span class="mw-page-title-main">807 Ceraskia</span>

    807 Ceraskia is an elongated Eos asteroid from the outer regions of the asteroid belt. It was discovered on 18 April 1915, by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in southwest Germany. The S-type asteroid has a rotation period of 7.4 hours and measures approximately 24 kilometers in diameter. It was named after Belarusian–Soviet astronomer Vitold Cerasky (1849–1925).

    <span class="mw-page-title-main">838 Seraphina</span>

    838 Seraphina is a dark and large background asteroid, approximately 58 kilometers in diameter, located in the outer regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 24 September 1916. The primitive P-type asteroid has a rotation period of 15.7 hours and is rather spherical in shape. Any reference to the origin of the asteroid's name is unknown.

    <span class="mw-page-title-main">1219 Britta</span>

    1219 Britta, provisional designation 1932 CJ, is a stony background asteroid from the inner regions of the asteroid belt, approximately 11 kilometers in diameter. It was discovered on 6 February 1932, by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in southern Germany. The likely elongated S-type asteroid has a rotation period of 5.57 hours. Any reference of its name to a person is unknown.

    <span class="mw-page-title-main">1665 Gaby</span>

    1665 Gaby, provisional designation 1930 DQ, is a stony asteroid and a relatively slow rotator from the inner regions of the asteroid belt, approximately 11 kilometers in diameter. It was discovered on 27 February 1930, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany. It was later named after Gaby Reinmuth, the discoverer's daughter-in-law.

    <span class="mw-page-title-main">1772 Gagarin</span>

    1772 Gagarin is a stony background asteroid from the central region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 6 February 1968, by Russian astronomer Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean Peninsula. The asteroid was named after cosmonaut Yuri Gagarin.

    <span class="mw-page-title-main">1188 Gothlandia</span>

    1188 Gothlandia, provisional designation 1930 SB, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 12 kilometers in diameter. Discovered by astronomer Josep Comas i Solà at the Fabra Observatory in 1930, the asteroid was later named after the ancient name of the Spanish autonomous community of Catalonia.

    <span class="mw-page-title-main">2156 Kate</span> Highly elongated background asteroid

    2156 Kate is a highly elongated background asteroid from the inner regions of the asteroid belt. The asteroid was discovered on 23 September 1917, by Soviet–Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. It was named for Kate Kristensen, wife of astronomer L. K. Kristensen. The bright S-type/A-type asteroid has a rotation period of 5.6 hours and measures approximately 8 kilometers in diameter.

    <span class="mw-page-title-main">1379 Lomonosowa</span>

    1379 Lomonosowa is a stony background asteroid from the central regions of the asteroid belt, approximately 19 kilometers in diameter. Discovered by Grigory Neujmin at the Simeiz Observatory in 1936, the asteroid was later named after Russian physicist and astronomer Mikhail Lomonosov.

    <span class="mw-page-title-main">1389 Onnie</span> Asteroid

    1389 Onnie, provisional designation 1935 SS1, is a stony Koronian asteroid from the outer region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 28 September 1935, by Dutch astronomer Hendrik van Gent at Leiden Southern Station, annex to the Johannesburg Observatory in South Africa.

    <span class="mw-page-title-main">1366 Piccolo</span>

    1366 Piccolo, provisional designation 1932 WA, is an asteroid from the background population of the outer asteroid belt, approximately 28 kilometers in diameter. It was discovered on 29 November 1932, by astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle. The asteroid was named after Auguste Cauvin, chief-editor of the Belgian newspaper Le Soir.

    <span class="mw-page-title-main">1192 Prisma</span>

    1192 Prisma, provisional designation 1931 FE, is an elongated Phocaea asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered by German astronomer Friedrich Schwassmann at the Bergedorf Observatory in Hamburg on 17 March 1931. The asteroid was named after the Bergedorf Spectral Catalogue, an astronomical catalog.

    References

    1. 1 2 3 4 5 "849 Ara (A912 CD)". Minor Planet Center. Retrieved 7 March 2020.
    2. Noah Webster (1884) A Practical Dictionary of the English Language
    3. 1 2 3 Schmadel, Lutz D. (2007). "(849) Ara". Dictionary of Minor Planet Names . Springer Berlin Heidelberg. p.  78. doi:10.1007/978-3-540-29925-7_850. ISBN   978-3-540-00238-3.
    4. 1 2 3 4 5 6 7 8 "JPL Small-Body Database Browser: 849 Ara (A912 CD)" (2020-01-31 last obs.). Jet Propulsion Laboratory . Retrieved 7 March 2020.
    5. 1 2 "Asteroid 849 Ara – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 7 March 2020.
    6. 1 2 3 4 5 6 "Asteroid 849 Ara". Small Bodies Data Ferret. Retrieved 7 March 2020.
    7. 1 2 3 Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System. Bibcode:2016PDSS..247.....M . Retrieved 7 March 2020.
    8. 1 2 Harris, A. W.; Young, J. W.; Dockweiler, Thor; Gibson, J.; Poutanen, M.; Bowell, E. (January 1992). "Asteroid lightcurve observations from 1981". Icarus. 95 (1): 115–147. Bibcode:1992Icar...95..115H. doi:10.1016/0019-1035(92)90195-D. ISSN   0019-1035.
    9. 1 2 3 Behrend, Raoul. "Asteroids and comets rotation curves – (849) Ara". Geneva Observatory. Retrieved 7 March 2020.
    10. 1 2 Hanuš, J.; Viikinkoski, M.; Marchis, F.; Ďurech, J.; Kaasalainen, M.; Delbo', M.; et al. (May 2017). "Volumes and bulk densities of forty asteroids from ADAM shape modeling". Astronomy and Astrophysics. 601: A114. arXiv: 1702.01996 . Bibcode:2017A&A...601A.114H. doi:10.1051/0004-6361/201629956. ISSN   0004-6361. S2CID   119432730.
    11. 1 2 Belskaya, I. N.; Fornasier, S.; Tozzi, G. P.; Gil-Hutton, R.; Cellino, A.; Antonyuk, K.; et al. (March 2017). "Refining the asteroid taxonomy by polarimetric observations". Icarus. 284: 30–42. Bibcode:2017Icar..284...30B. doi:10.1016/j.icarus.2016.11.003. hdl: 11336/63617 . ISSN   0019-1035.
    12. 1 2 3 4 Erasmus, N.; McNeill, A.; Mommert, M.; Trilling, D. E.; Sickafoose, A. A.; Paterson, K. (June 2019). "A Taxonomic Study of Asteroid Families from KMTNET-SAAO Multiband Photometry". The Astrophysical Journal Supplement Series. 242 (2): 15. arXiv: 1903.08019 . Bibcode:2019ApJS..242...15E. doi: 10.3847/1538-4365/ab1344 . ISSN   0067-0049.
    13. 1 2 Gandolfi, D.; Cigna, M.; Fulvio, D.; Blanco, C. (January 2009). "CCD and photon-counting photometric observations of asteroids carried out at Padova and Catania observatories". Planetary and Space Science. 57 (1): 1–9. arXiv: 0810.1560 . Bibcode:2009P&SS...57....1G. doi:10.1016/j.pss.2008.09.014. ISSN   0032-0633. S2CID   18929245.
    14. Erasmus, N.; McNeill, A.; Mommert, M.; Trilling, D. E.; Sickafoose, A. A.; van Gend, C. (July 2018). "Taxonomy and Light-curve Data of 1000 Serendipitously Observed Main-belt Asteroids". The Astrophysical Journal Supplement Series. 237 (1): 19. arXiv: 1805.04478 . Bibcode:2018ApJS..237...19E. doi: 10.3847/1538-4365/aac38f . ISSN   0067-0049.
    15. 1 2 3 4 "LCDB Data for (849) Ara". Asteroid Lightcurve Database (LCDB). Retrieved 7 March 2020.
    16. Marciniak, A.; Michałowski, T.; Hirsch, R.; Polińska, M.; Kamiński, K.; Kwiatkowski, T.; et al. (April 2009). "Photometry and models of selected main belt asteroids. VI. 160 Una, 747 Winchester, and 849 Ara". Astronomy and Astrophysics. 498 (1): 313–320. Bibcode:2009A&A...498..313M. doi: 10.1051/0004-6361/200811078 . ISSN   0004-6361.
    17. Schmidt, Richard E. (July 2017). "Near-IR Minor Planet Photometry from Burleith Observatory" (PDF). Minor Planet Bulletin. 44 (3): 191–192. Bibcode:2017MPBu...44..191S. ISSN   1052-8091. Archived from the original (PDF) on 23 February 2020. Retrieved 7 March 2020.
    18. Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)
    19. Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T . Retrieved 7 March 2020.
    20. Ďurech, Josef; Kaasalainen, Mikko; Herald, David; Dunham, David; Timerson, Brad; Hanuš, Josef; et al. (August 2011). "Combining asteroid models derived by lightcurve inversion with asteroidal occultation silhouettes". Icarus. 214 (2): 652–670. arXiv: 1104.4227 . Bibcode:2011Icar..214..652D. doi:10.1016/j.icarus.2011.03.016. ISSN   0019-1035. S2CID   119271216.