1796 Riga

Last updated

1796 Riga
Discovery [1]
Discovered by N. Chernykh
Discovery site Crimean Astrophysical Obs.
Discovery date16 May 1966
Designations
(1796) Riga
Named after
Riga (capital city) [2]
1966 KB ·1935 GE
1941 FC1 ·1947 GA
1950 TF2 ·1953 GW
1960 JA ·A907 TG
A907 UD
main-belt  ·(outer) [1]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 66.06 yr (24,129 days)
Aphelion 3.5474 AU
Perihelion 3.1668 AU
3.3571 AU
Eccentricity 0.0567
6.15 yr (2,247 days)
142.11°
0° 9m 36.72s / day
Inclination 22.585°
186.73°
25.620°
Physical characteristics
Dimensions66.2±6.6 km [3]
68.089±1.037 km [4]
68.167±0.298 km [5]
71±7 km [6]
73.83±1.8 km [7]
85.79±1.57 km [8]
10.608±0.002 h [9] [lower-alpha 1]
11.0±0.01 h [10]
16 h [11]
22.226±0.001 h [12]
0.028±0.001 [8]
0.0376±0.002 [7]
0.04±0.01 [6]
0.044±0.005 [5]
0.0442±0.0082 [4]
0.05±0.01 [3]
XFCU (Tholen) [1]
Cb (SMASS) [1]
P [4]  · C [13] [14]
B–V = 0.676 [1]
U–B = 0.289 [1]
9.59±0.40 [14]  ·9.84 (IRAS:12) [1] [7]  ·9.84 [3] [4] [6] [8] [13]

    1796 Riga, provisional designation 1966 KB, is a dark asteroid from the outer region of the asteroid belt, approximately 70 kilometers in diameter. It was discovered on 16 May 1966, by Russian astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. [15] It is named after the Latvian capital Riga. [2]

    Contents

    Orbit and classification

    The asteroid orbits the Sun in the outer main-belt at a distance of 3.2–3.5  AU once every 6 years and 2 months (2,247 days). Its orbit has an eccentricity of 0.06 and an inclination of 23° with respect to the ecliptic. [1] The body was first identified as "1907 TG" at the U.S Taunton Observatory ( 803 ) in 1907, and its first used precovery was taken at the Goethe Link Observatory in 1953, extending the asteroid's observation arc by 13 years prior to its official discovery observation. [15] It is a member of the Cybele group of asteroids. [16]

    Spectral type

    The carbonaceous C-type asteroid is also classified as a very dark and featureless reddish P-type body by the NEOWISE survey of the Wide-field Infrared Survey Explorer (WISE). [4] [13] [14] In the Tholen and SMASS taxonomy, it has a XFCU and Cb subtype, respectively. [1]

    Diameter and albedo

    According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and NASA's WISE/NEOWISE mission, the asteroid measures between 66.2 and 85.7 kilometers in diameter and its surface has an albedo between 0.028 and 0.05. [3] [4] [5] [6] [7] [8] The Collaborative Asteroid Lightcurve Link (CALL) agrees with the results obtained by IRAS, adopting a diameter of 73.83 kilometers with an albedo of 0.0376, based on an absolute magnitude of 9.84. [13]

    Rotation period

    Several rotational lightcurve for this asteroid were obtained from photometric observations since 1997. They gave a variety of rotation periods from 10.608 to 22.226 hours with inconsistent brightness variations in the range of 0.05 to 0.40 magnitude ( U=2/2-/n.a./2 ). [9] [10] [11] [12] [lower-alpha 1] CALL adopts the results of the most observations made by astronomer Julian Oey at the Australian Blue Mountains Observatory (Q68) in March 2014, which gave a period of 22.226±0.001 hours and an amplitude of 0.40±0.05 magnitude ( U=2 ). [12] [13]

    Naming

    The minor planet was named after Riga, the capital of Latvia and location of the Astronomical Observatory of the University of Latvia. The name was proposed by Matiss A. Dirikis, who was a member of the observatory at the Latvian State University, and after whom the asteroid 1805 Dirikis is named. [2] The official naming citation was published by the Minor Planet Center on 25 September 1971 ( M.P.C. 3185). [17]

    Notes

    1. 1 2 Lightcurve plot of 1796 Riga, Palmer Divide Observatory, by B. D. Warner (2003), with a rotation period 10.608±0.002 hours and a brightness amplitude of 0.14±0.02 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)

    Related Research Articles

    Hercynia, provisional designation 1900 FK, is a background asteroid from the outer regions of the asteroid belt, approximately 38 kilometers in diameter. It was discovered on 21 September 1900, by astronomers Max Wolf and Arnold Schwassmann at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named for the ancient Hercynian Forest, known to the Romans as "Hercynia silva".

    <span class="mw-page-title-main">1032 Pafuri</span> Dark background asteroid from the outer regions of the asteroid belt

    1032 Pafuri, provisional designation 1924 SA, is a dark background asteroid from the outer regions of the asteroid belt, approximately 65 kilometers in diameter. It was discovered on 30 May 1924, by English astronomer Harry Edwin Wood at the Union Observatory in Johannesburg, South Africa. The asteroid was named for the river in the Pafuri Triangle in South Africa, created by the confluence of the Limpopo and Levubu rivers. The body's spectral type and rotation period are still poorly determined.

    <span class="mw-page-title-main">1042 Amazone</span>

    1042 Amazone, provisional designation 1925 HA, is a dark asteroid and slow rotator in the outer asteroid belt, approximately 70 kilometers in diameter. It was discovered on 22 April 1925, by German astronomer Karl Reinmuth at Heidelberg Observatory in southern Germany. It is named after the Amazons from Greek mythology.

    1092 Lilium, provisional designation 1924 PN, is a dark, carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 44 kilometers in diameter. It was discovered on 12 January 1924, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany. The asteroid was named after the flower Lilium.

    1146 Biarmia, provisional designation 1929 JF, is a metallic background asteroid from the outer regions of the asteroid belt, approximately 32 kilometers in diameter. It was discovered on 7 May 1929, by Russian astronomer Grigory Neujmin at the Simeiz Observatory on the Crimean peninsula. The asteroid was named for the Bjarmaland mentioned in Norse sagas.

    1166 Sakuntala, provisional designation 1930 MA, is a stony background asteroid from the central regions of the asteroid belt, approximately 26 kilometers in diameter. Discovered by Praskovjya Parchomenko at Simeiz Observatory in 1930, the asteroid was named after the figure of Shakuntala from an ancient Indian drama.

    <span class="mw-page-title-main">1294 Antwerpia</span>

    1294 Antwerpia (prov. designation: 1933 UB1) is a dark background asteroid from the central regions of the asteroid belt. It was discovered on 24 October 1933, by astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle. The carbonaceous C-type asteroid has a rotation period of 6.6 hours and measures approximately 35 kilometers (22 miles) in diameter. It was named for the Belgian city of Antwerp.

    1304 Arosa, provisional designation 1928 KC, is a metallic asteroid from the outer region of the asteroid belt, approximately 40 kilometers in diameter. It was discovered on 21 May 1928, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany. It was named after the Swiss mountain village of Arosa.

    4063 Euforbo is a large Jupiter trojan from the Greek camp, approximately 100 kilometers in diameter. It was discovered on 1 February 1989, by Italian astronomers at the San Vittore Observatory near Bologna, Italy. The dark D-type asteroid is one of the 25 largest Jupiter trojans and has a rotation period of 8.8 hours. It was named after Euphorbus (Euforbo) from Greek mythology.

    1177 Gonnessia, provisional designation 1930 WA, is a dark background asteroid from the outer regions of the asteroid belt, approximately 99 kilometers in diameter. It was discovered on 24 November 1930, by French astronomer Louis Boyer at the Algiers Observatory in Algeria, North Africa, and named after astronomer François Gonnessiat.

    1384 Kniertje, provisional designation 1934 RX, is a dark Adeonian asteroid from the central regions of the asteroid belt, approximately 26 kilometers in diameter. It was discovered on 9 September 1934, by Dutch astronomer Hendrik van Gent at the Union Observatory in Johannesburg, South Africa. The asteroid was named after a character in the Dutch play Op Hoop van Zegen by Herman Heijermans.

    1264 Letaba, provisional designation 1933 HG, is a carbonaceous asteroid and possible tumbler from the background population of the outer asteroid belt, approximately 70 kilometers in diameter. It was discovered on 21 April 1933, by South African astronomer Cyril Jackson at the Union Observatory in Johannesburg. The asteroid was named for the Letaba River in eastern South Africa.

    <span class="mw-page-title-main">1353 Maartje</span>

    1353 Maartje, provisional designation 1935 CU, is an Eoan asteroid from the outer regions of the asteroid belt, approximately 37 kilometers in diameter. It was discovered on 13 February 1935, by Dutch astronomer Hendrik van Gent at the Union Observatory in Johannesburg, South Africa. The asteroid was named after Maartje Mekking, daughter of a staff member at the Dutch Leiden Observatory.

    1238 Predappia, provisional designation 1932 CA, is a dark Adeonian asteroid from the central regions of the asteroid belt, approximately 21 kilometers in diameter. It was discovered on 4 February 1932, by astronomer Luigi Volta at the Observatory of Turin in Pino Torinese, Italy. It was later named after the Italian village of Predappio.

    <span class="mw-page-title-main">1436 Salonta</span>

    1436 Salonta, provisional designation 1936 YA, is a dark background asteroid from the outer regions of the asteroid belt, approximately 60 kilometers in diameter. Discovered by György Kulin at the Konkoly Observatory in 1936, the asteroid was later named for the Romanian city of Salonta, the birthplace of the discoverer.

    1330 Spiridonia, provisional designation 1925 DB, is a dark background asteroid of primitive composition, located in the outer regions of the asteroid belt, approximately 65 kilometers in diameter. It was discovered on 17 February 1925, by Soviet astronomer Vladimir Albitsky at the Simeiz Observatory on the Crimean peninsula. The asteroid was named after the discoverer's brother-in-law, Spiridon Zaslavskij.

    3682 Welther, provisional designation A923 NB, is a background asteroid from the central regions of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 12 July 1923, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany. The asteroid has a rotation period of 3.6 hours. It was named after Barbara Welther, an American historian of science at CfA.

    <span class="mw-page-title-main">1301 Yvonne</span>

    1301 Yvonne is a carbonaceous background asteroid from the background population of the intermediate asteroid belt, approximately 21 kilometers in diameter. It was discovered on 7 March 1934, by French astronomer Louis Boyer at the Algiers Observatory in North Africa. The asteroid was named for the discoverer's sister, Yvonne Boyer

    1296 Andrée, provisional designation 1933 WE, is a stony Nysian asteroid from the inner regions of the asteroid belt, approximately 25 kilometers in diameter. It was discovered on 25 November 1933, by French astronomer Louis Boyer at the North African Algiers Observatory, Algeria, and named after the discoverer's niece.

    <span class="mw-page-title-main">1339 Désagneauxa</span>

    1339 Désagneauxa, provisional designation 1934 XB, is a stony Eoan asteroid from the outer region of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 4 December 1934, by French astronomer Louis Boyer at the North African Algiers Observatory in Algeria. A few nights later, the asteroid was independently discovered by astronomers Grigory Neujmin and Eugène Delporte, at the Crimean Simeiz and Belgian Uccle Observatory, respectively. It was later named after discoverer's brother-in-law.

    References

    1. 1 2 3 4 5 6 7 8 9 10 "JPL Small-Body Database Browser: 1796 Riga (1966 KB)" (2016-11-04 last obs.). Jet Propulsion Laboratory . Retrieved 1 July 2017.
    2. 1 2 3 Schmadel, Lutz D. (2007). "(1796) Riga". Dictionary of Minor Planet Names – (1796) Riga. Springer Berlin Heidelberg. p. 144. doi:10.1007/978-3-540-29925-7_1797. ISBN   978-3-540-00238-3.
    3. 1 2 3 4 Alí-Lagoa, V.; Licandro, J.; Gil-Hutton, R.; Cañ; ada-Assandri, M.; Delbo', M.; et al. (June 2016). "Differences between the Pallas collisional family and similarly sized B-type asteroids". Astronomy and Astrophysics. 591: 11. Bibcode:2016A&A...591A..14A. doi: 10.1051/0004-6361/201527660 . hdl: 11336/63614 . Retrieved 10 August 2016.
    4. 1 2 3 4 5 6 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv: 1109.6407 . Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
    5. 1 2 3 Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv: 1406.6645 . Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121 . Retrieved 29 October 2016.
    6. 1 2 3 4 Alí-Lagoa, V.; de León, J.; Licandro, J.; Delbó, M.; Campins, H.; Pinilla-Alonso, N.; et al. (June 2013). "Physical properties of B-type asteroids from WISE data". Astronomy and Astrophysics. 554: 16. arXiv: 1303.5487 . Bibcode:2013A&A...554A..71A. doi:10.1051/0004-6361/201220680 . Retrieved 29 October 2016.
    7. 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 – IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T . Retrieved 17 October 2019.
    8. 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)
    9. 1 2 Warner, Brian D. (April 2011). "Upon Further Review: VI. An Examination of Previous Lightcurve Analysis from the Palmer Divide Observatory". The Minor Planet Bulletin. 38 (2): 96–101. Bibcode:2011MPBu...38...96W. ISSN   1052-8091 . Retrieved 17 November 2015.
    10. 1 2 Warner, Brian D. (March 2004). "Rotation rates for asteroids 875, 926, 1679, 1796, 3915, 4209, and 34817". The Minor Planet Bulletin. 31 (1): 19–22. Bibcode:2004MPBu...31...19W. ISSN   1052-8091 . Retrieved 17 November 2015.
    11. 1 2 Chiorny, V. G.; Shevchenko, V. G.; Krugly, Yu. N.; Velichko, F. P.; Gaftonyuk, N. M. (May 2007). "Photometry of asteroids: Lightcurves of 24 asteroids obtained in 1993 2005". Planetary and Space Science. 55 (7–8): 986–997. Bibcode:2007P&SS...55..986C. doi:10.1016/j.pss.2007.01.001 . Retrieved 17 November 2015.
    12. 1 2 3 Oey, Julian (January 2016). "Lightcurve Analysis of Asteroids from Blue Mountains Observatory in 2014". The Minor Planet Bulletin. 43 (1): 45–51. Bibcode:2016MPBu...43...45O. ISSN   1052-8091 . Retrieved 29 October 2016.
    13. 1 2 3 4 5 "LCDB Data for (1796) Riga". Asteroid Lightcurve Database (LCDB). Retrieved 29 October 2016.
    14. 1 2 3 Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv: 1506.00762 . Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007 . Retrieved 29 October 2016.
    15. 1 2 "1796 Riga (1966 KB)". Minor Planet Center. Retrieved 29 October 2016.
    16. De Prá, M. N.; et al. (September 2018), "PRIMASS visits Hilda and Cybele groups", Icarus, 311: 35–51, arXiv: 1711.02071 , Bibcode:2018Icar..311...35D, doi:10.1016/j.icarus.2017.11.012.
    17. Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN   978-3-642-01964-7.