1496 Turku

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
1496 Turku
Discovery [1]
Discovered by Y. Väisälä
Discovery site Turku Obs.
Discovery date 22 September 1938
MPC designation (1496) Turku
Named after
Turku[2] (Finnish city)
1938 SA1 · 1928 QN
1928 RE · 1950 EC
1954 MH · 1957 HB
main-belt · (inner)
Flora[3] · background [4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 88.02 yr (32,148 days)
Aphelion 2.5631 AU
Perihelion 1.8490 AU
2.2060 AU
Eccentricity 0.1619
3.28 yr (1,197 days)
0° 18m 2.88s / day
Inclination 2.5005°
Physical characteristics
Dimensions 7.47±0.31 km[5]
7.758±0.072 km[6]
7.973±0.018 km[7]
8.19 km (calculated)[3]
6.47±0.01 h[8]
6.47375±0.00001 h[9]
0.24 (assumed)[3]
S (assumed)[3]
12.40[5] · 12.42±0.25[10] · 12.6[1][3] · 12.9[7]

1496 Turku, provisional designation 1938 SA1, is a Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 22 September 1938, by astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory in Turku, Finnland.[11] The asteroid was named for the Finnish city of Turku.[2]

Orbit and classification[edit]

Turku is a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main belt.[3] It is, however, a non-family asteroid from the main belt's background population when applying the Hierarchical Clustering Method to its proper orbital elements.[4]

It orbits the Sun in the inner main-belt at a distance of 1.8–2.6 AU once every 3 years and 3 months (1,197 days). Its orbit has an eccentricity of 0.16 and an inclination of 3° with respect to the ecliptic.[1] The body's observation arc begins with its first identification as 1928 QN at Johannesburg Observatory in August 1928, more than 10 years prior to its official discovery observation at Turku.[11]

Physical characteristics[edit]

Turku is an assumed S-type asteroid, which is also the Flora family's overall spectral type.[3]

Rotation period and poles[edit]

In April 2006, a rotational lightcurve of Turku was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a rotation period of 6.47 hours with a brightness amplitude of 0.51 magnitude, indicative of a non-spherical shape (U=3-).[8]

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database, gave a concurring period of 6.47375 hours, as well as a spin axis of (75.0°, −75.0°) in ecliptic coordinates (λ, β).[9]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Turku measures between 7.47 and 7.973 kilometers in diameter and its surface has an albedo between 0.1930 and 0.347.[5][6][7]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of the Flora family – and calculates a diameter of 8.19 kilometers based on an absolute magnitude of 12.6.[3]


This minor planet was named after Finnish city of Turku, location of the discovering observatory and home of the discoverer Yrjö Väisälä. In ancient times, Turku was the capital of Finland.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 1350).[12]


  1. ^ a b c d "JPL Small-Body Database Browser: 1496 Turku (1938 SA1)" (2016-08-23 last obs.). Jet Propulsion Laboratory. Retrieved 27 September 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1496) Turku. Springer Berlin Heidelberg. p. 119. ISBN 978-3-540-00238-3. Retrieved 27 September 2017. 
  3. ^ a b c d e f g h "LCDB Data for (1496) Turku". Asteroid Lightcurve Database (LCDB). Retrieved 27 September 2017. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 27 September 2017. 
  5. ^ 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 27 September 2017. 
  6. ^ 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 27 September 2017. 
  7. ^ 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 27 September 2017. 
  8. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1496) Turku". Geneva Observatory. Retrieved 27 September 2017. 
  9. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database" (PDF). Astronomy and Astrophysics. 587: 6. arXiv:1601.02909Freely accessible. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 27 September 2017. 
  10. ^ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 27 September 2017. 
  11. ^ a b "1496 Turku (1938 SA1)". Minor Planet Center. Retrieved 27 September 2017. 
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 September 2017. 

External links[edit]