993 Moultona
| Discovery [1] | |
|---|---|
| Discovered by | G. van Biesbroeck |
| Discovery site | Yerkes Obs. |
| Discovery date | 12 January 1923 |
| Designations | |
| (993) Moultona | |
Named after | Forest Ray Moulton (American astronomer) |
| 1923 NJ · 1928 BA 1960 WD · 1964 PQ 1967 CN | |
| main-belt [1][2] · (outer) Koronis [3][4] | |
| Orbital characteristics [2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 86.00 yr (31,410 d) |
| Aphelion | 2.9991 AU |
| Perihelion | 2.7218 AU |
| 2.8604 AU | |
| Eccentricity | 0.0485 |
| 4.84 yr (1,767 d) | |
| 272.19° | |
| 0° 12m 13.32s / day | |
| Inclination | 1.7799° |
| 184.26° | |
| 249.56° | |
| Physical characteristics | |
| 12.43±1.13 km[5][6] 15.15±1.17 km[7] | |
| 5.2712±0.0007 h[8][9] | |
| 0.147[7] 0.315[5][6] | |
| S (assumed)[8] | |
| 11.4[1][2][5][6][8] 11.80[7] | |
993 Moultona, provisional designation 1923 NJ, is a Koronian asteroid from the outer regions of the asteroid belt, approximately 14 kilometers (8.7 miles) in diameter. It was discovered on 12 January 1923, by astronomer George Van Biesbroeck at the Yerkes Observatory in Williams Bay, Wisconsin, in the United States.[1] The likely elongated asteroid has a rotation period of 5.3 hours.[8] It was named after American astronomer Forest Ray Moulton.[10]
Orbit and classification
[edit]Moultona is a core member of the Koronis family (605),[3][4] a very large outer asteroid family with nearly co-planar ecliptical orbits.[11] It orbits the Sun in the outer main-belt at a distance of 2.7–3.0 AU once every 4 years and 10 months (1,767 days; semi-major axis of 2.86 AU). Its orbit has an eccentricity of 0.05 and an inclination of 2° with respect to the ecliptic.[2] The body's observation arc begins with a precovery taken at the Lowell Observatory in October 1931, more than 12 years after to its official discovery observation at Williams Bay.[1]
Naming
[edit]This minor planet was named after Forest Ray Moulton (1872–1952), an American astronomer and mathematician known for research in celestial mechanics. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 50). The lunar crater Moulton was also named in his honor.[10]
Physical characteristics
[edit]Moultona is an assumed S-type asteroid.[8]
Rotation period
[edit]In December 2014, a rotational lightcurve of Moultona was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a well-defined rotation period of 5.2712±0.0007 hours with a high brightness amplitude of 0.73 magnitude, indicative of a non-spherical, elongated shape (U=3)
Diameter and albedo
[edit]According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Moultona measures between 12.43 and 15.15 kilometers in diameter and its surface has an albedo between 0.147 and 0.315.[6][5][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 and calculates a diameter of 14.24 kilometers based on an absolute magnitude of 11.4.[8]
References
[edit]- ^ a b c d e "993 Moultona (1923 NJ)". Minor Planet Center. Retrieved 19 July 2018.
- ^ a b c d "JPL Small-Body Database Browser: 993 Moultona (1923 NJ)" (2017-10-29 last obs.). Jet Propulsion Laboratory. Retrieved 19 July 2018.
- ^ a b "Asteroid 993 Moultona". Small Bodies Data Ferret. Retrieved 19 July 2018.
- ^ a b "Asteroid (993) Moultona – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 25 May 2018.
- ^ a b c d 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 19 July 2018.
- ^ 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.
- ^ 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 e f "LCDB Data for (993) Moultona". Asteroid Lightcurve Database (LCDB). Retrieved 19 July 2018.
- ^ Behrend, Raoul. "Asteroids and comets rotation curves – (993) Moultona". Geneva Observatory. Retrieved 19 July 2018.
- ^ a b Schmadel, Lutz D. (2007). "(993) Moultona". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 86. doi:10.1007/978-3-540-29925-7_994. ISBN 978-3-540-00238-3.
- ^ 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.
External links
[edit]- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 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
- 993 Moultona at AstDyS-2, Asteroids—Dynamic Site
- 993 Moultona at the JPL Small-Body Database
