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] The discovery of the asteroid took place during Kowal's follow-up observations of Jupiter's moon Leda, which he had discovered one month prior.[10]
| Discovery[1] | |
|---|---|
| Discovered by | C. Kowal |
| Discovery site | Palomar Obs. |
| Discovery date | 17 October 1974 |
| Designations | |
| (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 | 3.5154 AU |
| 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] | |
Orbit and classification
editLoretta 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
editLoretta has been characterized as a carbonaceous C-type asteroid.[1]
Diameter and albedo
editAccording 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
editA 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
editThis minor planet was named by the discoverer after his daughter, Loretta Kowal.[2] The official naming citation was published by the Minor Planet Center on 1 June 1975 (M.P.C. 3828).[11]
References
edit- ^ 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.
- ^ 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.
- ^ a b c d e f g "LCDB Data for (1939) Loretta". Asteroid Lightcurve Database (LCDB). Retrieved 9 December 2016.
- ^ 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:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 9 December 2016.
- ^ 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. (online, AcuA catalog p. 153)
- ^ 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". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
- ^ 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:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 9 December 2016.
- ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1939) Loretta". Geneva Observatory. Retrieved 9 December 2016.
- ^ a b "1939 Loretta (1974 UC)". Minor Planet Center. Retrieved 9 December 2016.
- ^ Kowal, C. T.; Aksnes, K.; Marsden, B. G.; Roemer, E. (1974). "Thirteenth satellite of Jupiter". Astronomical Journal. 80: 463. Bibcode:1975AJ.....80..460K. doi:10.1086/111766.
- ^ 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.
External links
edit- Asteroid Lightcurve Database (LCDB), query form (info Archived 21 July 2011 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 1939 Loretta at AstDyS-2, Asteroids—Dynamic Site
- 1939 Loretta at the JPL Small-Body Database
