1518 Rovaniemi

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1518 Rovaniemi
1518Rovaniemi (Lightcurve Inversion).png
Lightcurve-based 3D-model of Rovaniemi
Discovery [1]
Discovered by Y. Väisälä
Discovery site Turku Obs.
Discovery date 15 October 1938
MPC designation (1518) Rovaniemi
Named after
Rovaniemi (Finnish city)[2]
1938 UA · 1928 TL
1951 SH
main-belt · (inner)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 88.74 yr (32,412 days)
Aphelion 2.5449 AU
Perihelion 1.9053 AU
2.2251 AU
Eccentricity 0.1437
3.32 yr (1,212 days)
0° 17m 49.2s / day
Inclination 6.7137°
Physical characteristics
Dimensions 7.46±1.30 km[5]
7.76±0.71 km[6]
8.480±0.167 km[7]
8.98 km (calculated)[3]
9.019±0.070 km[8]
5.247±0.001 h[9]
5.249±0.002 h[10]
0.24 (assumed)[3]
12.3[8] · 12.34[6] · 12.4[1][3] · 12.68[5]

1518 Rovaniemi, provisional designation 1938 UA, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. Discovered by Yrjö Väisälä at the Turku Observatory in 1938, the asteroid was later named for the Finnish city of Rovaniemi.


Rovaniemi was discovered on 15 October 1938, by Finnish astronomer Yrjö Väisälä at the Turku Observatory in Southwest Finland. Six nights later, it was independently discovered by Belgian astronomer Eugène Delporte at Uccle Observatory on 21 October 1938. The Minor Planet Center, however, only recognizes the first discoverer.[2][11]

The asteroid was first identified as 1928 TL at Simeiz Observatory on 7 October 1928.[a] The body's observation arc begins two weeks later at Simeiz on 21 October 1928, almost 10 years prior to the asteroid's official discovery observation at Turku.[11]

Orbit and classification[edit]

Rovaniemi is a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt.[3][4][12]:23 It orbits the Sun in the inner main-belt at a distance of 1.9–2.5 AU once every 3 years and 4 months (1,212 days). Its orbit has an eccentricity of 0.14 and an inclination of 7° with respect to the ecliptic.[1]

Physical characteristics[edit]

Rovaniemi is an assumed stony S-type asteroid,[3] which corresponds to the overall spectral type of the Flora family.[12]:23

Rotation period[edit]

In January 2009, two rotational lightcurves of Rovaniemi were obtained from photometric observations by René Roy at Blauvac Observatory (627) in France, and by Brian Warner at the Palmer Divide Observatory (716) in Colorado, United States. Lightcurve analysis gave a rotation period of 5.247 and 5.249 hours with a brightness amplitude of 0.26 and 0.25 magnitude, respectively (U=2+/3).[9][10]

Spin axis[edit]

In 2013, an international study modeled a lightcurve from various data sources including the Uppsala Asteroid Photometric Catalogue and the Palomar Transient Factory survey. The lightcurve gave a concurring period of 5.25047 hours and allowed for the determination of two spin axis of (62.0°, 60.0°) and (265.0°, 45.0°) in ecliptic coordinates (λ, β).[13]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Rovaniemi measures between 7.46 and 9.019 kilometers in diameter and its surface has an albedo between 0.2631 and 0.340.[5][6][7][8]

The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the Flora family's largest member and namesake – and calculates a diameter of 8.98 kilometers based on an absolute magnitude of 12.4.[3]


This minor planet was named after the Finnish city of Rovaniemi, located just six kilometers south of the Arctic Circle.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3929).[14]


  1. ^ Alternatively to the Simeiz Observatory, it is also possible that observations at the Italian Turin Observatory on 13 and 14 October 1928, lead to the assignment of Rovaniemi's first provisional designation, 1928 TL.


  1. ^ a b c d "JPL Small-Body Database Browser: 1518 Rovaniemi (1938 UA)" (2017-07-04 last obs.). Jet Propulsion Laboratory. Retrieved 6 September 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1518) Rovaniemi. Springer Berlin Heidelberg. p. 121. ISBN 978-3-540-00238-3. Retrieved 6 September 2017. 
  3. ^ a b c d e f g h "LCDB Data for (1518) Rovaniemi". Asteroid Lightcurve Database (LCDB). Retrieved 6 September 2017. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 6 September 2017. 
  5. ^ a b c d 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:1606.08923Freely accessible. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 6 September 2017. 
  6. ^ 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 6 September 2017. 
  7. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 6 September 2017. 
  8. ^ 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 6 September 2017. 
  9. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1518) Rovaniemi". Geneva Observatory. Retrieved 6 September 2017. 
  10. ^ a b Warner, Brian D. (July 2009). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2008 December - 2009 March". The Minor Planet Bulletin. 36 (3): 109–116. Bibcode:2009MPBu...36..109W. ISSN 1052-8091. Retrieved 6 September 2017. 
  11. ^ a b "1518 Rovaniemi (1938 UA)". Minor Planet Center. Retrieved 6 September 2017. 
  12. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families" (PDF). Asteroids IV: 297–321. arXiv:1502.01628Freely accessible. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. Retrieved 6 September 2017. 
  13. ^ Hanus, J.; Durech, J.; Broz, M.; Marciniak, A.; Warner, B. D.; Pilcher, F.; et al. (March 2013). "Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution". Astronomy and Astrophysics. 551: 16. arXiv:1301.6943Freely accessible. Bibcode:2013A&A...551A..67H. doi:10.1051/0004-6361/201220701. Retrieved 6 September 2017. 
  14. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 6 September 2017. 

External links[edit]