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957 Camelia /kəˈmliə/ is a large, carbonaceous background asteroid and slow rotator, approximately 70 kilometers (43 miles) in diameter. It is located in the outer regions of the asteroid belt and was discovered on 7 September 1921, by astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in Germany and given the provisional designations A921 RF and 1921 JX.[1] The C-type asteroid (Cb) has a long rotation period of at least 150 hours. It was named after the genus of flowering plants, Camellia.[3]

957 Camelia
Discovery [1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date7 September 1921
Designations
(957) Camelia
Pronunciation/kəˈmliə/[2]
Named after
Camellia[3]
(genus of flowers)
A921 RF · 1932 AG
1958 BM · 1921 JX
main-belt[1][4] · (outer)
background[5][6] · slow[a]
Orbital characteristics[4]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc97.94 yr (35,773 d)
Aphelion3.1595 AU
Perihelion2.6884 AU
2.9240 AU
Eccentricity0.0806
5.00 yr (1,826 d)
199.16°
0° 11m 49.56s / day
Inclination14.761°
232.78°
224.57°
Physical characteristics
  • 64.36±1.01 km[7]
  • 73.73±1.5 km[8]
  • 91.548±0.450 km[9]
150±10 h[10][a]
  • 0.025±0.004[9]
  • 0.0429±0.002[8]
  • 0.056±0.002[7]
9.9[1][4]

Orbit and classification

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Camelia 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 2.7–3.2 AU once every 5 years (1,826 days; semi-major axis of 2.92 AU). Its orbit has an eccentricity of 0.08 and an inclination of 15° with respect to the ecliptic.[4] The body's observation arc begins at Heidelberg Observatory on 4 October 1926, five years after its official discovery observation.[1]

Naming

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This minor planet was named after the genus of Asian shrubs and trees, Petunia. This genus of flowering plants belongs to the Theaceae (tea family). The prominent ornamental greenhouse shrubs show glossy evergreen leaves and roselike flowers. The naming was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 92).[3] Only a minority of minor planets are named after plants.

Reinmuth's flowers

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Due to his many discoveries, Karl Reinmuth submitted a large list of 66 newly named asteroids in the early 1930s. The list covered his discoveries with numbers between (1009) and (1200). This list also contained a sequence of 28 asteroids, starting with this asteroid, that were all named after plants, in particular flowering plants (also see list of minor planets named after animals and plants).[3]

Physical characteristics

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In the Tholen-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Camelia is a carbonaceous C-type asteroid, while in the SMASS-like taxonomy of the S3OS2, it is a Cb-subtype that transitions from the C-type to the "brighter" B-type asteroids.[6][11]

Rotation period

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In August 2000, a rotational lightcurve of Camelia was obtained from photometric observations by Brian Warner at the Palmer Divide Observatory (716) in Colorado. The originally published lightcurve analysis gave a wrong rotation period of 5.391±0.02 hours with a brightness variation of 0.32±0.02 magnitude (U=0).[12] In July 2010, and with the availability of improved analysis tools and techniques along with the experience gained over more than a decade, Warner reviewed and recalibrated the original data set and determined a period of at least 150±10 hours with an amplitude of more than 0.30 (U=1+).[10][a] With such a long period, Camelia is a slow rotator. While the slowest rotators have periods above 1000 hours, the vast majority of asteroids have a much shorter rotation period of 2.2 to 20 hours.

Diameter and albedo

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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), Camelia measures (64.36±1.01), (73.73±1.5) and (91.548±0.450) kilometers in diameter, and its surface has an albedo of (0.056±0.002), (0.0429±0.002) and (0.025±0.004), respectively.[7][8][9] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0357 and a diameter of 73.63 km based on an absolute magnitude of 10.71.[13]

Over the course of a few years, the WISE team has also published several smaller mean-diameters of (57.808±23.443 km), (60.832±20.524 km) and (66.460±0.577 km) with corresponding albedos of (0.044±0.040), (0.043±0.029) and (0.053±0.007).[6][13]

Notes

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  1. ^ a b c Revised lightcurve plot of 957 Camelia, Palmer Divide Observatory, B. D. Warner (2000, 2010) rotation period 150±10 hours with a brightness amplitude of 0.30 mag. Quality code of 1+. Summary figures at the LCDB

References

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  1. ^ a b c d e "957 Camelia (A921 RF)". Minor Planet Center. Retrieved 13 February 2020.
  2. ^ "camelia". Merriam-Webster.com Dictionary. Merriam-Webster.
  3. ^ a b c d Schmadel, Lutz D. (2007). "(957) Camelia". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 84. doi:10.1007/978-3-540-29925-7_958. ISBN 978-3-540-00238-3.
  4. ^ a b c d "JPL Small-Body Database Browser: 957 Camelia (A921 RF)" (2019-08-17 last obs.). Jet Propulsion Laboratory. Retrieved 13 February 2020.
  5. ^ a b "Asteroid 957 Camelia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 13 February 2020.
  6. ^ a b c d "Asteroid 957 Camelia". Small Bodies Data Ferret. Retrieved 13 February 2020.
  7. ^ a b c 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. ^ a b c 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 13 February 2020.
  9. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8.
  10. ^ a b Warner, Brian D. (July 2010). "Upon Further Review: I. An Examination of Previous Lightcurve Analysis from the Palmer Divide Observatory" (PDF). The Minor Planet Bulletin. 37 (3): 127–130. Bibcode:2010MPBu...37..122S. Archived from the original (PDF) on 13 February 2020. Retrieved 13 February 2020.
  11. ^ a b c 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 13 February 2020.
  12. ^ Warner, Brian D. (March 2001). "Asteroid Photometry at the Palmer Divide Observatory: Results for 706 Hirundo, 957 Camelia, and 1719 Jens" (PDF). The Minor Planet Bulletin. 28 (1): 4–5. Bibcode:2001MPBu...28....4W. Archived from the original (PDF) on 13 February 2020. Retrieved 13 February 2020.
  13. ^ a b "LCDB Data for (957) Camelia". Asteroid Lightcurve Database (LCDB). Retrieved 13 February 2020.
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