2513 Baetslé

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 by	S. Arend
Discovery site	Uccle Obs.
Discovery date	19 September 1950
Designations
MPC designation	(2513) Baetslé
Named after	Paul-Louis Baetslé[2]
Alternative designations	1950 SH · 1936 PC 1943 RA · 1943 RC 1950 TK · 1950 TW2 1964 VO2 · 1971 UH3 1974 QV · 1981 QO
Minor planet category	main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	73.57 yr (26,870 days)
Aphelion	2.7004 AU
Perihelion	1.8713 AU
Semi-major axis	2.2859 AU
Eccentricity	0.1813
Orbital period (sidereal)	3.46 yr (1,262 days)
Mean anomaly	138.26°
Inclination	3.1618°
Longitude of ascending node	257.61°
Argument of perihelion	97.789°
Physical characteristics
Dimensions	5.013±0.080[4] 5.054±0.086 km[5] 16.67±1.8 km[6] 16.69 km (derived)[3]
Synodic rotation period	6.0792±0.0004 h[a]
Geometric albedo	0.0278±0.007[6] 0.0333 (derived)[3] 0.221±0.021[4] 0.3032±0.0453[5]
Spectral type	S[3]
Absolute magnitude (H)	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 classification

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 characteristics

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]

Naming

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]

Notes

1. 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