2513 Baetslé, provisional designation 1950 SH, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 16 kilometers in diameter.

2513 Baetslé
Discovery [1]
Discovered byS. Arend
Discovery siteUccle Obs.
Discovery date19 September 1950
MPC designation(2513) Baetslé
Named after
Paul-Louis Baetslé[2]
1950 SH · 1936 PC
1943 RA · 1943 RC
1950 TK · 1950 TW2
1964 VO2 · 1971 UH3
1974 QV · 1981 QO
main-belt · Flora [3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc73.57 yr (26,870 days)
Aphelion2.7004 AU
Perihelion1.8713 AU
2.2859 AU
3.46 yr (1,262 days)
Physical characteristics
5.054±0.086 km[5]
16.67±1.8 km[6]
16.69 km (derived)[3]
6.0792±0.0004 h[a]
0.0333 (derived)[3]
13.20[3] · 13.27±0.27[7] · 13.4[1][6][5]

It was discovered on 19 September 1950, by Belgian astronomer Sylvain Arend at the Royal Observatory in Uccle, Belgium.[8] It was later named after astronomer Paul-Louis Baetslé.[2]

Orbit and classificationEdit

Baetslé is a member of the Flora family, one of the largest groups of rather bright and stony asteroids, and orbits the Sun in the inner main-belt at a distance of 1.9–2.7 AU once every 3 years and 6 months (1,262 days). Its orbit has an eccentricity of 0.18 and an inclination of 3° with respect to the ecliptic.[1] Its orbit is almost coplanar. Its first used observation dates back to 1943, when it was identified as 1943 RA at Heidelberg Observatory, extending the body's observation arc by 7 years prior to its official discovery observation.[8]

Physical characteristicsEdit

Baetslé takes 6.08 hours for a full a rotation around its axis.[a] Two observations by the Infrared Astronomical Satellite, IRAS, showed an absolute magnitude of 13.40 and a low geometric albedo of 0.03.[3] While the size, rotational period and orbital data are commonly found among main-belt asteroids, the albedo was exceptionally low and suggested that the body's composition could be mostly carbonaceous.

However, subsequent observations by the Wide-field Infrared Survey Explorer's NEOWISE mission gave a higher albedo of 0.22 and 0.30 and the Collaborative Asteroid Lightcurve Link derives a value of 0.33, assuming the body to be of a stony rather than of a carbonaceous composition.[3][5] This also concurs with the fact that Baetslé is a member of the Flora family of rather bright and stony asteroids.[3]


This minor planet was named in memory of Belgian astronomer Paul-Louis Baetslé (1909–1983), professor at the Brussels Royal Military School and a friend of Sylvain Arend.[2] The official naming citation was published on 20 December 1983 (M.P.C. 8404).[9]


  1. ^ a b Pravec (2009) web: rotation period 6.0792±0.0004 hours with a brightness amplitude of 0.32 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (2513) Baetsle


  1. ^ a b c d "JPL Small-Body Database Browser: 2513 Baetsle (1950 SH)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 31 May 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(2513) Baetslé". Dictionary of Minor Planet Names – (2513) Baetslé. Springer Berlin Heidelberg. p. 205. doi:10.1007/978-3-540-29925-7_2514. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g h "LCDB Data for (2513) Baetslé". Asteroid Lightcurve Database (LCDB). Retrieved 6 December 2016.
  4. ^ a b 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:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 6 December 2016.
  5. ^ 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". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  6. ^ a b c 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.
  7. ^ 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 6 December 2016.
  8. ^ a b "2513 Baetsle (1950 SH)". Minor Planet Center. Retrieved 6 December 2016.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 6 December 2016.

External linksEdit