1533 Saimaa

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
1533 Saimaa
Discovery [1]
Discovered by Y. Väisälä
Discovery site Turku Obs.
Discovery date 19 January 1939
MPC designation (1533) Saimaa
Named after
Saimaa (Finnish lake)[2]
1939 BD · 1934 FA
1936 QC · 1936 RP
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 80.71 yr (29,480 days)
Aphelion 3.1226 AU
Perihelion 2.8990 AU
3.0108 AU
Eccentricity 0.0371
5.22 yr (1,908 days)
0° 11m 19.32s / day
Inclination 10.710°
Physical characteristics
Dimensions 24.298±0.279 km[5]
26.13±1.5 km[6]
26.16 km (derived)[3]
27.88±1.68 km[7]
7.08 h[8]
7.1181±0.0002 h[9]
0.1270 (derived)[3]
Tholen = S[1][3]
B–V = 0.790 [1]
U–B = 0.450 [1]
10.77[3][8] · 10.77±0.26[10] · 10.82[1][5][6][7]

1533 Saimaa, provisional designation 1939 BD, is a stony Eoan asteroid from the outer regions of the asteroid belt, approximately 26 kilometers in diameter. It was discovered on 19 January 1939, by astronomer Yrjö Väisälä at the Iso-Heikkilä Observatory near Turku, Finland.[11] The asteroid was named after lake Saimaa in Finland.[2]

Orbit and classification[edit]

Saimaa is a member the Eos family (606),[4] the largest asteroid family of the outer main belt consisting of nearly 10,000 asteroids.[12]:23 It orbits the Sun at a distance of 2.9–3.1 AU once every 5 years and 3 months (1,908 days). Its orbit has an eccentricity of 0.04 and an inclination of 11° with respect to the ecliptic.[1] The asteroid was first identified as 1934 FA at Uccle Observatory in March 1934. The body's observation arc begins with its identification as 1936 QC at Heidelberg Observatory in August 1936, more than 2 years prior to its official discovery observation at Turku.[11]

Physical characteristics[edit]

In the Tholen classification, Saimaa is a common stony S-type asteroid.[1][3] The overall spectral type for members of the Eos family is that of a K-type.[12]:23

Rotation period[edit]

In September 1983, a first rotational lightcurve of Saimaa was obtained from photometric observations by American astronomer Richard Binzel at CTIO and McDonald Observatory. Lightcurve analysis gave a well-defined rotation period of 7.08 hours with a brightness variation of 0.18 magnitude (U=3).[8] In February 2007, another lightcurve obtained by French amateur astronomer René Roy gave a concurring period of 7.1181 hours and an amplitude of 0.26 magnitude (U=3).[9]

Diameter and albedo[edit]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Saimaa measures between 22.40 and 27.88 kilometers in diameter and its surface has an albedo between 0.107 and 0.165.[5][6][7]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1270 and a diameter of 26.16 kilometers based on an absolute magnitude of 10.77.[3]


This minor planet was named after lake Saimaa in southeastern Finland. With an overall area of 4,400 square kilometres (1,700 sq mi), it is the country's largest lake and one of the largest lakes in Europe.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3929).[13]


  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1533 Saimaa (1939 BD)" (2017-05-04 last obs.). Jet Propulsion Laboratory. Retrieved 9 October 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1533) Saimaa. Springer Berlin Heidelberg. p. 121. ISBN 978-3-540-00238-3. Retrieved 9 October 2017. 
  3. ^ a b c d e f g "LCDB Data for (1533) Saimaa". Asteroid Lightcurve Database (LCDB). Retrieved 9 October 2017. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 9 October 2017. 
  5. ^ a b c d e 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 9 October 2017. 
  6. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. Bibcode:2004PDSS...12.....T. Retrieved 9 October 2017. 
  7. ^ 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. Retrieved 9 October 2017. 
  8. ^ a b c Binzel, R. P. (October 1987). "A photoelectric survey of 130 asteroids". Icarus: 135–208. Bibcode:1987Icar...72..135B. doi:10.1016/0019-1035(87)90125-4. ISSN 0019-1035. Retrieved 9 October 2017. 
  9. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1533) Saimaa". Geneva Observatory. Retrieved 9 October 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 9 October 2017. 
  11. ^ a b "1533 Saimaa (1939 BD)". Minor Planet Center. Retrieved 9 October 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 9 October 2017. 
  13. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 9 October 2017. 

External links[edit]