1568 Aisleen

1568 Aisleen, provisional designation 1946 QB, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 12.5 kilometers in diameter. It was discovered on 21 August 1946, by South African astronomer Ernest Johnson at Johannesburg Observatory in South Africa.[14] It is named for the discoverer's wife, Aisleen Johnson.[2]

1568 Aisleen

Lightcurve-based 3D-model of Aisleen
Discovery [1]
Discovered by	E. L. Johnson
Discovery site	Johannesburg Obs.
Discovery date	21 August 1946
Designations
MPC designation	(1568) Aisleen
Named after	Aisleen Johnson (discoverer's wife)[2]
Alternative designations	1946 QB
Minor planet category	main-belt · Phocaea [3][4][5]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	70.70 yr (25,824 days)
Aphelion	2.9502 AU
Perihelion	1.7557 AU
Semi-major axis	2.3529 AU
Eccentricity	0.2538
Orbital period	3.61 yr (1,318 days)
Mean anomaly	221.76°
Mean motion	0° 16^m 23.16^s / day
Inclination	24.867°
Longitude of ascending node	146.18°
Argument of perihelion	229.03°
Physical characteristics
Dimensions	11.983±0.072 km[6] 12.448±0.084 km[7] 12.49±2.52 km[8] 12.67 km (calculated)[3] 14.04±0.96 km[9]
Rotation period	6.67597±0.00005 h[10] 6.68±0.02 h[11] 6.683±0.005 h[12]
Geometric albedo	0.130±0.019[9] 0.165±0.028[7] 0.1793±0.0322[6] 0.21±0.06[8] 0.23 (assumed)[3]
Spectral type	S [3]
Absolute magnitude (H)	11.57±0.21[13] · 11.7[1][3] · 12.1[6][9] · 12.14[8] ·

Orbit and classification

The S-type asteroid is a member of the Phocaea family (701), a group of asteroids with similar orbital characteristics.[4][5] It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 7 months (1,318 days). Its orbit has an eccentricity of 0.25 and an inclination of 25° with respect to the ecliptic.[1] As no precoveries were taken, and no prior identifications were made, Aisleen's observation arc begins with its official discovery observation at Johannesburg.[14]

Physical characteristics

Rotation and pole

In August 2000, a rotational lightcurve of Aisleen was obtained from photometric observations made by Glen Malcolm at the Roach Motel Observatory (856) in California. The analysis gave a well-defined rotation period of 6.68 hours during which the brightness varied by 0.56 in magnitude (U=3).[11] In April 2014, photometric observations by Brian D. Warner gave a period of 6.683 hours with an amplitude of 0.31 magnitude (U=3).[12] A modeled lightcurve from various data sources gave a concurring period of 6.67597 hours[10] and found a pole of (109°,−68°).[12]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Aisleen measures between 11.98 and 14.04 kilometers in diameter, and its surface has an albedo between 0.130 and 0.21.[6][7][8][9] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for Phocaea asteroids of 0.23 – derived from 25 Phocaea, the family's most massiv member and namesake – and calculates a diameter of 12.67 kilometers based on an absolute magnitude of 11.7.[3]

Naming

This minor planet was named by the discoverer for his wife, Aisleen Johnson.[2] The official naming citation was published by the Minor Planet Center on 31 January 1962 (M.P.C. 2116).[15]

References

1. "JPL Small-Body Database Browser: 1568 Aisleen (1946 QB)" (2017-05-04 last obs.). Jet Propulsion Laboratory. Retrieved 5 June 2017.
2. Schmadel, Lutz D. (2007). "(1568) Aisleen". Dictionary of Minor Planet Names – (1568) Aisleen. Springer Berlin Heidelberg. p. 124. doi:10.1007/978-3-540-29925-7_1569. ISBN 978-3-540-00238-3.
3. "LCDB Data for (1568) Aisleen". Asteroid Lightcurve Database (LCDB). Retrieved 29 December 2016.
4. Carruba, Valerio; Rosa, D. A. (September 2009). "An Analysis of the Region of the Phocaea Dynamical Family". American Astronomical Society, DPS Meeting #41, #27.04. 41: 27.04. Bibcode:2009DPS....41.2704C. Retrieved 29 December 2016.
5. "Asteroid 1568 Aisleen – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 October 2019.
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. 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 29 December 2016.
8. Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 29 December 2016.
9. 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 17 October 2019. (online, AcuA catalog p. 153)
10. Hanus, J.; Durech, J.; Broz, M.; Warner, B. D.; Pilcher, F.; Stephens, R.; et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy & Astrophysics. 530: 16. arXiv:1104.4114. Bibcode:2011A&A...530A.134H. doi:10.1051/0004-6361/201116738. Retrieved 29 December 2016.
11. Malcolm, G. (December 2001). "Rotational Periods and Lightcurves of 1166 Sakuntala and 1568 Aisleen". The Minor Planet Bulletin. 28: 64. Bibcode:2001MPBu...28...64M. Retrieved 29 December 2016.
12. Warner, Brian D. (October 2014). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 March-June". The Minor Planet Bulletin. 41 (4): 235–241. Bibcode:2014MPBu...41..235W. ISSN 1052-8091. Retrieved 2 January 2016.
13. Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 29 December 2016.
14. "1568 Aisleen (1946 QB)". Minor Planet Center. Retrieved 29 December 2016.
15. 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

• Asteroid Lightcurve Database (LCDB), query form (info)
• 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
• 1568 Aisleen at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1568 Aisleen at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters