1939 Loretta

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1939 Loretta
Discovery [1]
Discovered by C. Kowal
Discovery site Palomar Obs.
Discovery date 17 October 1974
Designations
MPC designation (1939) Loretta
Named after
Loretta Kowal
(daughter of discoverer)[2]
1974 UC · 1934 JE
1934 LQ · 1939 EH
1939 GP · 1950 DT
1950 ES · 1951 MF
1955 CA · 1969 TE5
1975 TZ5 · 1975 XW
main-belt · Themistian [3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 67.21 yr (24,547 days)
Aphelion|Aphelion 3.5154 AU
Perihelion|Perihelion 2.7291 AU
3.1222 AU
Eccentricity 0.1259
5.52 yr (2,015 days)
24.968°
0° 10m 43.32s / day
Inclination 0.9058°
40.473°
189.36°
Physical characteristics
Dimensions 26.34±0.46 km[4]
29.08±0.51 km[5]
29.83 km (derived)[3]
30.243±0.335 km[6]
30.365±0.351[7]
25 h[8]
0.0721 (derived)[3]
0.092±0.013[7]
0.0927±0.0089[6]
0.101±0.020[4]
0.103±0.004[5]
C[3]
10.8[5][6] · 11.0[4] · 11.1[1][3]

1939 Loretta, provisional designation 1974 UC, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 30 kilometers in diameter. It was discovered on 17 October 1974, by American astronomer Charles Kowal at Palomar Observatory in California, who named it after his daughter, Loretta Kowal.[2][9]

Orbit and classification[edit]

Loretta is a member of the Themis family, a dynamical family of main-belt asteroids with nearly coplanar ecliptical orbits.[3] It orbits the Sun in the outer main-belt at a distance of 2.7–3.5 AU once every 5 years and 6 months (2,015 days). Its orbit has an eccentricity of 0.13 and an inclination of 1° with respect to the ecliptic.[1]

First identified as 1934 JE at the South African Johannesburg Observatory, Loretta's first used observation was made at the Finnish Turku Observatory in 1939, extending the body's observation arc by 35 years prior to its discovery.[9]

Physical characteristics[edit]

Loretta has been characterized as a carbonaceous C-type asteroid.[1]

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Loretta measures between 26.3 and 30.4 kilometers in diameter, and its surface has an albedo between 0.092 and 0.101.[4][5][6][7] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.072 and a diameter of 29.8 kilometers with an absolute magnitude of 11.1.[3]

Rotation period[edit]

A fragmentary rotational lightcurve of Loretta was obtained from photometric observations made by French amateur astronomer Pierre Antonini in March 2011. It gave an approximate rotation period of 25 hours with a brightness variation of 0.12 magnitude (U=1).[8]

Naming[edit]

This minor planet was named by the discoverer after his daughter, Loretta Kowal.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3828).[10]

References[edit]

  1. ^ a b c d e "JPL Small-Body Database Browser: 1939 Loretta (1974 UC)" (2017-05-05 last obs.). Jet Propulsion Laboratory. Retrieved 10 June 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). "(1939) Loretta". Dictionary of Minor Planet Names – (1939) Loretta. Springer Berlin Heidelberg. p. 155. doi:10.1007/978-3-540-29925-7_1940. ISBN 978-3-540-00238-3. Retrieved 9 December 2016. 
  3. ^ a b c d e f g "LCDB Data for (1939) Loretta". Asteroid Lightcurve Database (LCDB). Retrieved 9 December 2016. 
  4. ^ a b c d 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:1209.5794Freely accessible. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 9 December 2016. 
  5. ^ a b c d 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. Retrieved 9 December 2016. 
  6. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 9 December 2016. 
  7. ^ a b c 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:1406.6645Freely accessible. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 9 December 2016. 
  8. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1939) Loretta". Geneva Observatory. Retrieved 9 December 2016. 
  9. ^ a b "1939 Loretta (1974 UC)". Minor Planet Center. Retrieved 9 December 2016. 
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 9 December 2016. 

External links[edit]