2423 Ibarruri

2423 Ibarruri, provisional designation 1972 NC, is an eccentric, tumbling and rare-type asteroid, classified as slow rotator and sizable Mars-crosser from the inner regions of the asteroid belt, approximately 5 kilometers in diameter.

2423 Ibarruri

Discovery[1]
Discovered by	L. Zhuravleva
Discovery site	Crimean Astrophysical Obs.
Discovery date	14 July 1972
Designations
MPC designation	(2423) Ibarruri
Named after	Rubén Ibárruri (Hero of the Soviet Union)[2]
Alternative designations	1972 NC · 1930 SV 1943 TB · 1956 VC 1972 PB
Minor planet category	Mars-crosser[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	60.59 yr (22,129 days)
Aphelion	2.8068 AU
Perihelion	1.5702 AU
Semi-major axis	2.1885 AU
Eccentricity	0.2825
Orbital period (sidereal)	3.24 yr (1,183 days)
Mean anomaly	315.42°
Inclination	4.0571°
Longitude of ascending node	264.96°
Argument of perihelion	80.645°
Physical characteristics
Dimensions	4.899±1.085[5] 6.50 km (calculated)[3]
Synodic rotation period	73.08±0.10 h[6] 139.79±0.04 h[a] 139.9±0.2 h[7] 139.92±0.01 h[8]
Geometric albedo	0.20 (assumed)[3] 0.330±0.167[5]
Spectral type	SMASS = A[1][9] L[10] · S[11] · C[3]
Absolute magnitude (H)	13.3[1] · 13.44±1.15[10] · 13.20[11] · 13.3[3]

The asteroid was discovered by Russian–Ukrainian astronomer Lyudmila Zhuravleva at the Crimean Astrophysical Observatory in Nauchnyj, on 14 July 1972.^[4] It was named after Spanish communist Rubén Ruiz Ibárruri.^[2]

Orbit and classification

Ibarruri orbits the Sun in the inner main-belt at a distance of 1.6–2.8 AU once every 3 years and 3 months (1,183 days). Its orbit has an eccentricity of 0.28 and an inclination of 4° with respect to the ecliptic.^[1]

Physical characteristics

The spectral type of the asteroid is that of a rare A-type in the SMASS taxonomy, with its surface consisting of almost pure olivine, which gives the body a very reddish color. As of November 2015, only 17 minor planets of this type are known.^[12]

As a spectroscopic A-type asteroid, it belongs to the larger group of bodies with a silicaceous composition. However, the Collaborative Asteroid Lightcurve Link classifies the asteroid into the carbonaceous group, despite the fact that is assumes a relatively high geometric albedo of 0.20,^[3] which is rather typical for stony asteroids.

Slow rotator and tumbler

Ibarruri has a notably slow rotation period of 140 hours,^[a][7] and seems to be in a non-principal axis rotation (NPAR), colloquially called as "tumbling".^[13]

Naming

This minor planet was named after Rubén Ruiz Ibárruri (1920–1942), son of Spanish communist leader Dolores Ibárruri and a posthumous Hero of the Soviet Union. He enlisted in the Soviet army and died in the early stage of the Battle of Stalingrad in September 1942.^[2] The official naming citation was published by the Minor Planet Center on 8 February 1982 (M.P.C. 6649).^[14]

Notes

1. Pravec (2011) web: lightcurve plot for (2423) Ibarruri with a rotation period 139.79±0.04 hours with a brightness amplitude of 0.74 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)