1261 Legia

1261 Legia, provisional designation 1933 FB, is a dark Themistian asteroid from the outer regions of the asteroid belt, approximately 32 kilometers in diameter. It was discovered on 23 March 1933, by astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle.^[13] The asteroid was named for the Belgian city of Liège (Luke).^[2]

1261 Legia

Discovery[1]
Discovered by	E. Delporte
Discovery site	Uccle Obs.
Discovery date	23 March 1933
Designations
MPC designation	(1261) Legia
Pronunciation	/ˈliːdʒiə/
Named after	Latin name for Liège[2] (Belgian city)
Alternative designations	1933 FB · 1938 CS 1938 DH · 1944 FD 1966 DG
Minor planet category	main-belt · (outer) Themis[3] · background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	84.28 yr (30,785 days)
Aphelion	3.6992 AU
Perihelion	2.5758 AU
Semi-major axis	3.1375 AU
Eccentricity	0.1790
Orbital period (sidereal)	5.56 yr (2,030 days)
Mean anomaly	57.530°
Mean motion	0° 10m 38.28s / day
Inclination	2.4274°
Longitude of ascending node	67.282°
Argument of perihelion	104.64°
Physical characteristics
Dimensions	31.20 km (derived)[3] 31.26±11.50 km[5] 31.28±1.3 km[6] 32.13±0.66 km[7] 32.576±0.126 km[8] 35.324±0.345 km[9] 36.56±0.35 km[10]
Synodic rotation period	8.693±0.007 h[11]
Geometric albedo	0.048±0.009[10] 0.0564±0.0127[9] 0.06±0.05[5] 0.0601 (derived)[3] 0.067±0.004[8] 0.070±0.003[7] 0.0719±0.006[6]
Spectral type	P[9] · S (assumed)[3]
Absolute magnitude (H)	11.00[6][7][9] · 11.10[10] · 11.12±0.72[12] · 11.2[1][3] · 11.29[5]

Orbit and classification

Legia is a Themistian asteroid that belongs to the Themis family (602), a very large family of carbonaceous asteroids, named after 24 Themis.^[3] It is, however, a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.^[4]

It orbits the Sun in the outer asteroid belt at a distance of 2.6–3.7 AU once every 5 years and 7 months (2,030 days; semi-major axis of 3.14 AU). Its orbit has an eccentricity of 0.18 and an inclination of 2° with respect to the ecliptic.^[1]

The body's observation arc begins at Uccle in March 1933, five days after its official discovery observation.^[13]

Physical characteristics

Legia has been characterized as a primitive and reddish P-type asteroid by the Wide-field Infrared Survey Explorer (WISE).^[9]

Rotation period

In January 2005, a rotational lightcurve of Legia was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Lightcurve analysis gave a rotation period of 8.693 hours with a brightness amplitude of 0.13 magnitude (U=2+).^[11]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Legia measures between 31.26 and 36.56 kilometers in diameter and its surface has an albedo between 0.048 and 0.0719.^{[5][6][7][8][9][10]}

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0601 and a diameter of 31.20 kilometers based on an absolute magnitude of 11.2.^[3]

Naming

This minor planet was named "Legia", the Latin name of the Belgian city of Liège (Luik). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 116).^[2]