1194 Aletta

1194 Aletta

Discovery[1]
Discovered by	C. Jackson
Discovery site	Johannesburg Obs.
Discovery date	13 May 1931
Designations
MPC designation	(1194) Aletta
Named after	Aletta Jackson (discoverer's wife)[2]
Alternative designations	1931 JG · 1946 KC 1962 SB
Minor planet category	main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc	85.07 yr (31,072 days)
Aphelion	3.1812 AU
Perihelion	2.6452 AU
Semi-major axis	2.9132 AU
Eccentricity	0.0920
Orbital period (sidereal)	4.97 yr (1,816 days)
Mean anomaly	138.73°
Mean motion	0° 11^m 53.52^s / day
Inclination	10.870°
Longitude of ascending node	291.32°
Argument of perihelion	243.18°
Physical characteristics
Dimensions	41.358±0.191 km[4] 42.67±0.77 km[5] 46.371±1.188 km[6] 55.22±20.92 km[7] 55.23 km (derived)[3] 55.39±1.4 km[8]
Synodic rotation period	19.7±0.1 h[9] 20.39±0.01 h[10] 20.3903±0.2170 h[11]
Geometric albedo	0.03±0.03[7] 0.0333 (derived)[3] 0.0375±0.0065[6] 0.0479±0.003[8] 0.085±0.004[5] 0.087±0.011[4]
Spectral type	C[3]
Absolute magnitude (H)	10.2[5][6][8] · 10.5[12] · 10.6[1][3][7] · 10.644±0.001 (R)[11]

1194 Aletta, provisional designation 1931 JG, is a carbonaceous asteroid from the outer region of the asteroid belt, approximately 55 kilometers in diameter. It was discovered on 13 May 1931, by South African astronomer Cyril Jackson at Johannesburg Observatory in South Africa.^[13] It was later named after the discoverer's wife Aletta Jackson.^[2]

Classification and orbit

Aletta is a dark C-type asteroid and orbits the Sun at a distance of 2.6–3.2 AU once every 4 years and 12 months (1,816 days). Its orbit has an eccentricity of 0.09 and an inclination of 11° with respect to the ecliptic.^[1] The body's observation arc begins at Johannesburg, one week after its official discovery observation. No precoveries were taken and no prior identifications were made.^[13]

Physical characteristics

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Aletta measures between 41.358 and 55.39 kilometers in diameter, and its surface has an albedo between 0.03 and 0.87.^{[4][5][6][7][8]} The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0333 and a diameter of 55.23 kilometers based on an absolute magnitude of 10.6.^[3]

Rotation period

In November 2007, American astronomer James W. Brinsfield obtained the first ever lightcurve of Aletta with period of 19.7 hours and a brightness variation of 0.32 magnitude at Via Capote Observatory (U=2).^[9] Two more lightcurves were obtained by Australian astronomer Julian Oey at Leura/Kingsgrove Observatory in March 2010, and by the Survey conducted at the Palomar Transient Factory, California, in October 2012. Lightcurve analysis gave a concurring rotation period of 20.39 and 20.3903 hours with an amplitude of 0.28 and 0.27 magnitude, respectively (U=2+/2).^[10][11]

Naming

The discoverer named this minor planet for his wife, Aletta Jackson (née Maria Aletta Lessing).^[2] Naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 111).^[2]

References

1. "JPL Small-Body Database Browser: 1194 Aletta (1931 JG)" (2016-06-14 last obs.). Jet Propulsion Laboratory. Retrieved 1 February 2017.
2. Schmadel, Lutz D. (2007). "(1194) Aletta". Dictionary of Minor Planet Names – (1194) Aletta. Springer Berlin Heidelberg. p. 100. doi:10.1007/978-3-540-29925-7_1195. ISBN 978-3-540-00238-3.
3. "LCDB Data for (1194) Aletta". Asteroid Lightcurve Database (LCDB). Retrieved 1 February 2017.
4. 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 1 February 2017.
5. 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)
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.
7. Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 1 February 2017.
8. 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 22 October 2019.
9. Brinsfield, James W. (June 2008). "The Rotation Periods of 531 Zerlina, 1194 Aleta 1352 Wawel, 2005 Hencke, 2648 Owa, and 3509 Sanshui". The Minor Planet Bulletin. 35 (2): 86–87. Bibcode:2008MPBu...35...86B. ISSN 1052-8091. Retrieved 1 February 2017.
10. Oey, Julian (October 2011). "Lightcurve Analysis of Asteroids from Leura and Kingsgrove Observatory for the Second Half of 2009 and 2010". The Minor Planet Bulletin. 38 (4): 221–223. Bibcode:2011MPBu...38..221O. ISSN 1052-8091. Retrieved 1 February 2017.
11. Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 1 February 2017.
12. Faure, Gerard; Garrett, Lawrence (October 2009). "Suggested Revised H Values of Selected Asteroids: Report Number 4". The Minor Planet Bulletin. 36 (4): 140–143. Bibcode:2009MPBu...36..140F. ISSN 1052-8091. Retrieved 1 February 2017.
13. "1194 Aletta (1931 JG)". Minor Planet Center. Retrieved 1 February 2017.

External links

• 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
• 1194 Aletta at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1194 Aletta at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters