791 Ani

Last updated

791 Ani
000791-asteroid shape model (791) Ani.png
Modelled shape of Ani from its lightcurve
Discovery [1]
Discovered by G. Neujmin
Discovery site Simeiz Obs.
Discovery date29 June 1914
Designations
(791) Ani
Named after
Historic city of Ani [2]
A914 MB ·1949 WH
1964 PO ·1975 XM
1914 UV
main-belt [1] [3]  ·(outer)
Meliboea [4] [5]  · Bg [6]
Orbital characteristics [3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc 104.08 yr (38,017 d)
Aphelion 3.7242 AU
Perihelion 2.5197 AU
3.1219 AU
Eccentricity 0.1929
5.52 yr (2,015 d)
33.057°
0° 10m 43.32s / day
Inclination 16.381°
129.81°
201.49°
Physical characteristics
Dimensions65.7  km × 103.5  km
Mean diameter
  • 97.87±1.15 km [7]
  • 99.799±11.027 km [8]
  • 103.52±1.9 km [9]
11.174±0.004  h [10]
  • (94.0°, −25.0°) (λ11) [11]
  • (269.0°, 4.0°) (λ22) [11]
  • 0.0329±0.001 [9]
  • 0.035±0.016 [8]
  • 0.037±0.001 [7]

    791 Ani (prov. designation: A914 MBor1914 UV) is a very large asteroid of the Meliboea family, located in the outer regions of the asteroid belt. It was discovered on 29 June 1914, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. [1] The dark carbonaceous C-type asteroid has a rotation period of 11.2 hours and measures approximately 65.7 × 103.5 kilometers, with a mean diameter of 100 km (62 mi). It was named after the historic Armenian city of Ani. [2]

    Contents

    Orbit and classification

    When applying the hierarchical clustering method (HCM) to its proper orbital elements, Ani is a member of the Meliboea family ( 604 ), [4] [5] a small family of carbonaceous asteroids in the outer main belt, named after its principal body, 137 Meliboea. [13] :23 However, according to another HCM-analysis by Milani and Knežević (AstDyS), it is a background asteroid as this analysis does not recognize the Meliboea family. [6] Ani orbits the Sun in the outer asteroid belt at a distance of 2.5–3.7  AU once every 5 years and 6 months (2,015 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.19 and an inclination of 16° with respect to the ecliptic. [3] The body's observation arc begins at Algiers Observatory in North Africa on 6 December 1915, some 17 months after its official discovery observation at Simeiz Observatory. [1]

    Naming

    This minor planet was named after the medieval city of Ani, which was destroyed by an earthquake in 1319. The ruins of the former capital of the Armenian kingdom are located near the border to Armenia, in what is now Turkey. Ani was known as "the city of 1001 churches". The naming was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 ( H 79 ). [2]

    Physical characteristics

    In the Tholen classification, Ani is a common, carbonaceous C-type asteroid. [3] It is also a common C-type in the Tholen-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), while in the survey's SMASS-like taxonomic variant, the asteroid is a hydrated carbonaceous subtype (Ch). [4] [12]

    Rotation period and poles

    In May 2018, a rotational lightcurve of Ani was obtained from photometric observations by American amateur astronomer Tom Polakis at the Command Module Observatory ( V02 ) in Arizona . Lightcurve analysis gave a well-defined rotation period of 11.174±0.004 hours with a brightness variation of 0.28±0.02 magnitude ( U=3 ). [10]

    In June 2002, Brian Warner at his Palmer Divide Observatory first observed this asteroid and later derived a period of 16.8±0.1 hours and an amplitude of 0.35±0.05 magnitude, based on poor data ( U=1 ). [lower-alpha 1] In December 2004, and in May 2007, two periods of 22.850±0.003 h and 22.85±0.05 h with a corresponding amplitude of 0.17±0.01 and 0.38±0.02 magnitude were determined by European astronomers Raymond Poncy ( 177 ) as well as Yves Revaz, Raoul Behrend, Alain Klotz, Michel Hernandez, Robert Soubie, Jean-François Gauthier, Bernard Tregon, Pierre Antonini, Laurent Bernasconi, Federico Manzini ( A12 ), Yassine Damerdji and Horacio Correia. The two periods are slightly longer than twice Polakis' period solution ( U=2/2− ). [14] In April 2007, astronomers at the Oakley Observatory ( 916 ), Indiana, obtained a period of 16.72±0.03 hours and an amplitude of 0.32±0.05 magnitude ( U=2 ). [15] In February 2011, French amateur astronomer René Roy determined a period of 12±0.5 hours and a brightness variation of 0.38±0.02 magnitude ( U=2 ). [14]

    A modeled lightcurve by Josef Ďurech and Josef Hanuš, using photometric data including from the Lowell Photometric Database and from the Wide-field Infrared Survey Explorer (WISE) was published in 2018. It gave a sidereal period of 11.16954±0.00002 and two spin axes at (94.0°, −25.0°) and (269.0°, 4.0°) in ecliptic coordinates (λ,β). [16] [11]

    Diameter and albedo

    According to the surveys carried out by the Japanese Akari satellite, the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), and the Infrared Astronomical Satellite IRAS, Ani measures (97.87±1.15), (99.799±11.027) and (103.52±1.9) kilometers in diameter and its surface has an albedo of (0.037±0.001), (0.035±0.016) and (0.0329±0.001), respectively. [7] [8] [9] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0329 and a diameter of 103.52 kilometers based on an absolute magnitude of 9.25. [11] Alternative mean-diameter measurements published by the WISE team include (82.500±5.957  km ), (83.31±21.31  km ), (93.29±31.33 km) and (116.865±1.024 km) with corresponding albedos of (0.0518±0.0131), (0.04±0.02), (0.04±0.02) and (0.026±0.003). [4] [11] On 7 April 2000, an asteroid occultation of Ani gave a best-fit ellipse dimension of (65.7 km × 103.5 km) with a good quality rating of 3. These timed observations are taken when the asteroid passes in front of a distant star. [4]

    Notes

    1. Lightcurve plot of (791) Ani, Palmer Divide Observatory, B. D. Warner (2002). Rotation period 16.8±0.1 hours with a brightness amplitude of >0.1 mag, based on a revision from 2011. Quality code is 1. Summary figures at the LCDB.

    Related Research Articles

    <span class="mw-page-title-main">2829 Bobhope</span>

    2829 Bobhope is a dark asteroid of the Meliboea family, from the outer region of the asteroid belt. It was discovered on 9 August 1948, by South African astronomer Ernest Leonard Johnson at Union Observatory in Johannesburg. The asteroid was later named after comedian Bob Hope. The asteroid has a rotation period of 6.1 hours and measures approximately 37 kilometers in diameter.

    763 Cupido is a Flora asteroid, tumbler and slow rotator from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 25 September 1913, by German astronomer Franz Kaiser at the Heidelberg-Königstuhl State Observatory in southwest Germany. The S/L-type asteroid has an exceptionally long rotation period of 151 hours. It was named by its Latin name after Cupid, the Roman god of erotic love, attraction and affection.

    777 Gutemberga is a dark and large background asteroid, approximately 66 kilometers in diameter, from the outer regions of the asteroid belt. It was discovered by German astronomer Franz Kaiser at the Heidelberg-Königstuhl State Observatory on 24 January 1914. The carbonaceous C-type asteroid (Cb) has a rotation period of 12.8 hours. It was named after Johannes Gutenberg, who introduced the printing press to Europe and started the Printing Revolution.

    783 Nora is a dark background asteroid from the inner regions of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 18 March 1914. The carbonaceous C-type asteroid has a longer-than average rotation period of 55.5 hours and measures approximately 40 kilometers in diameter. It was likely named after Nora Helmer, principal character in the play A Doll's House by Norwegian poet Henrik Ibsen.

    786 Bredichina is a carbonaceous and very large background asteroid, approximately 104 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered by German astronomer Franz Kaiser at the Heidelberg-Königstuhl State Observatory on 20 April 1914. The elongated C-type asteroid has a longer than average rotation period of 29.4 hours. It was named after Russian astronomer Fyodor Bredikhin (1831–1904).

    794 Irenaea is a dark background asteroid from the outer regions of the asteroid belt. It was discovered on 27 August 1914, by Austrian astronomer Johann Palisa at the Vienna Observatory. The presumed C-type asteroid has a rotation period of 9.1 hours and measures approximately 36 kilometers in diameter. It was likely named after Irene Hillebrand, daughter of Austrian astronomer Edmund Weiss (1837–1917).

    795 Fini is a dark and large background asteroid, approximately 76 kilometers in diameter, located in the central region of the asteroid belt. It was discovered by Austrian astronomer Johann Palisa at the Vienna Observatory on 26 September 1914. The carbonaceous C-type asteroid has a poorly determined rotation period of 9.3 hours and seems rather spherical in shape. Any reference of the asteroid's name to a person is unknown.

    821 Fanny is a dark background asteroid and slow rotator from the central regions of the asteroid belt. It was discovered on 31 March 1916, by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory in southwest Germany. The carbonaceous C-type asteroid (Ch) has an exceptionally long rotation period of 236.6 hours and measures approximately 29 kilometers in diameter. Any reference of the asteroid's name to a person is unknown.

    <span class="mw-page-title-main">856 Backlunda</span>

    856 Backlunda is a dark background asteroid from the inner region of the asteroid belt. It was discovered on 3 April 1916, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsula. The carbonaceous C-type asteroid has a rotation period of 12.1 hours and measures approximately 45 kilometers in diameter. It was named after Swedish-Russian astronomer Oskar Backlund (1846–1916).

    866 Fatme is a large background asteroid, approximately 86 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 25 February 1917. The X-type asteroid has a short rotation period of 5.8 hours. It was named after "Fatme", a character in the opera Abu Hassan by Carl Maria von Weber (1786–1826).

    <span class="mw-page-title-main">868 Lova</span>

    868 Lova is a large and dark background asteroid, approximately 51 kilometers in diameter, from the central regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 26 April 1917. The carbonaceous C-type asteroid (Ch) and has a long rotation period of 41.1 hours and is likely elongated in shape. The origin of the asteroid's name remains unknown.

    <span class="mw-page-title-main">874 Rotraut</span>

    874 Rotraut is a dark and elongated background asteroid, approximately 58 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 25 May 1917, by astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory is southwest Germany. The hydrated carbonaceous C-type asteroid (Ch) has a rotation period of 14.3 hours. It was likely named after the ballad Schön Rotraut by German lyric poet Eduard Mörike (1804–1875).

    927 Ratisbona is a large and dark background asteroid, approximately 76 kilometers in diameter, located in the outer region of the asteroid belt. It was discovered on 16 February 1920, by astronomer Max Wolf at the Heidelberg Observatory in southwest Germany. The carbonaceous C-type asteroid (CB) has a rotation period of 12.99 hours and is rather spherical in shape. It was named after the Bavarian city of Regensburg.

    946 Poësia is a Themis asteroid and slow rotator, approximately 39 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 11 February 1921 and given the provisional designations A921 CD and 1921 JC. The F-type asteroid has a long rotation period of 108.5 hours. It was named after the goddess of poetry.

    965 Angelica, is a large background asteroid from the outer regions of the asteroid belt, approximately 60 kilometers in diameter. It was discovered on 4 November 1921, by astronomer Johannes F. Hartmann at the La Plata Astronomical Observatory in Argentina. The dark X-type asteroid (Xc) with a low TJupiter has a rotation period of 26.8 hours and is likely spherical in shape. It was named after the discoverer's wife, Angelica Hartmann.

    977 Philippa is a large background asteroid from the outer regions of the asteroid belt, approximately 65 kilometers in diameter. It was discovered on 6 April 1922, by Russian–French astronomer Benjamin Jekhowsky at the Algiers Observatory in Northern Africa. The C-type asteroid is likely irregular in shape and has a rotation period of 15.4 hours. It was named after French financier Baron Philippe de Rothschild (1902–1988).

    1115 Sabauda is a carbonaceous Meliboean asteroid from the outer region of the asteroid belt, approximately 68 kilometers in diameter. Discovered in 1928 by Italian astronomer Luigi Volta, it was assigned the provisional designation 1928 XC. The asteroid was probably named after the House of Savoy, the former rulers of Italy.

    <span class="mw-page-title-main">1165 Imprinetta</span>

    1165 Imprinetta, provisional designation 1930 HM, is a carbonaceous Meliboean asteroid from the outer regions of the asteroid belt, approximately 49 kilometers (30 mi) in diameter. It was discovered on 24 April 1930 by Dutch astronomer Hendrik van Gent at the Union Observatory in Johannesburg, South Africa. The asteroid was named after Imprinetta Gent, wife of the discoverer.

    1184 Gaea, provisional designation 1926 RE, is an Aerian asteroid from the central regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 5 September 1926, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named after the goddess of Earth, Gaea (Gaia), from Greek mythology.

    <span class="mw-page-title-main">1369 Ostanina</span>

    1369 Ostanina is a dark and elongated asteroid of the Meliboea family, located in the outer region of the asteroid belt. It was discovered on 27 August 1935, by Soviet astronomer Pelageya Shajn at the Simeiz Observatory on the Crimean peninsula. The hydrated carbonaceous C-type asteroid has a rotation period of 8.4 hours and measures approximately 42 kilometers in diameter. It was named for the Russian village of Ostanin, birthplace of the discoverer.

    References

    1. 1 2 3 4 5 "791 Ani (A914 MB)". Minor Planet Center. Retrieved 28 March 2020.
    2. 1 2 3 Schmadel, Lutz D. (2007). "(791) Ani". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 74. doi:10.1007/978-3-540-29925-7_792. ISBN   978-3-540-00238-3.
    3. 1 2 3 4 5 6 7 8 "JPL Small-Body Database Browser: 791 Ani (A914 MB)" (2020-01-06 last obs.). Jet Propulsion Laboratory . Retrieved 28 March 2020.
    4. 1 2 3 4 5 "Asteroid 791 Ani – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 28 March 2020.
    5. 1 2 Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1997). "Asteroid Dynamical Families". NASA Planetary Data System: EAR-A-5-DDR-FAMILY-V4.1. Retrieved 28 March 2020.} (PDS main page)
    6. 1 2 "Asteroid 791 Ani – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 28 March 2020.
    7. 1 2 3 4 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)
    8. 1 2 3 4 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: EAR-A-COMPIL-5-NEOWISEDIAM-V1.0. Bibcode:2016PDSS..247.....M . Retrieved 28 March 2020.
    9. 1 2 3 4 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 28 March 2020.
    10. 1 2 Polakis, Tom (October 2018). "Lightcurve Analysis for Fourteen Main-belt Minor Planets" (PDF). Minor Planet Bulletin. 45 (4): 347–352. Bibcode:2018MPBu...45..347P. ISSN   1052-8091 . Retrieved 28 March 2020.
    11. 1 2 3 4 5 6 "LCDB Data for (791) Ani". Asteroid Lightcurve Database (LCDB). Retrieved 28 March 2020.
    12. 1 2 3 Lazzaro, D.; Angeli, C. A.; Carvano, J. M.; Mothé-Diniz, T.; Duffard, R.; Florczak, M. (November 2004). "S3OS2: the visible spectroscopic survey of 820 asteroids" (PDF). Icarus. 172 (1): 179–220. Bibcode:2004Icar..172..179L. doi:10.1016/j.icarus.2004.06.006 . Retrieved 28 March 2020.
    13. Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV. pp. 297–321. arXiv: 1502.01628 . Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN   9780816532131.
    14. 1 2 Behrend, Raoul. "Asteroids and comets rotation curves – (791) Ani". Geneva Observatory . Retrieved 28 March 2020.
    15. Sauppe, Jason; Torno, Steven; Lemke-Oliver, Robert; Ditteon, Richard (December 2007). "Asteroid Lightcurve Analysis at the Oakley Observatory - March/April 2007" (PDF). Minor Planet Bulletin. 34 (4): 119–122. Bibcode:2007MPBu...34..119S. ISSN   1052-8091. Archived from the original (PDF) on 20 February 2020. Retrieved 28 March 2020.
    16. Ďurech, J.; Hanuš, J.; Alí-Lagoa, V. (September 2018). "Asteroid models reconstructed from the Lowell Photometric Database and WISE data". Astronomy and Astrophysics. 617: A57. arXiv: 1807.02083 . Bibcode:2018A&A...617A..57D. doi:10.1051/0004-6361/201833437. ISSN   0004-6361.