1130 Skuld

1130 Skuld, provisional designation 1929 RC, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was named after Skuld from Norse mythology.^[2]

1130 Skuld

Modelled shape of Skuld from its lightcurve
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	2 September 1929
Designations
MPC designation	(1130) Skuld
Named after	Skuld (Norse mythology)[2]
Alternative designations	1929 RC · 1928 FJ 1949 UD · 1962 LA A906 VC
Minor planet category	main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	110.38 yr (40,316 days)
Aphelion	2.6701 AU
Perihelion	1.7864 AU
Semi-major axis	2.2282 AU
Eccentricity	0.1983
Orbital period (sidereal)	3.33 yr (1,215 days)
Mean anomaly	173.35°
Mean motion	0° 17m 46.68s / day
Inclination	2.1677°
Longitude of ascending node	216.13°
Argument of perihelion	113.81°
Physical characteristics
Dimensions	9.63±0.44 km[4] 9.99 km (derived)[3] 10.125±0.092 km[5] 10.24±0.64 km[6] 11.009±0.091 km[7]
Synodic rotation period	4.73±0.02 h[8] 4.807±0.002 h[9] 4.8079±0.0005 h[10] 4.810 h[a]
Geometric albedo	0.1995±0.0461[7] 0.24 (assumed)[3] 0.244±0.033[6] 0.302±0.031[4]
Spectral type	S[3]
Absolute magnitude (H)	12.0[1][4] · 12.10[6] · 12.17[3][7] · 12.17±0.02[9]

Discovery

Skuld was discovered on 2 September 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.^[11] The body was independently discovered by astronomers and fellow countrymen Arnold Schwassmann and Arno Wachmann at the Hamburger Bergedorf Observatory ten nights later.^[2]

It was first identified as A906 VC at Heidelberg in 1906, extending the asteroid's observation arc by 23 years prior to its official discovery observation.^[11]

Orbit and classification

Skuld is a member of the Flora family, one of the largest groups of stony S-type asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,215 days). Its orbit has an eccentricity of 0.20 and an inclination of 2° with respect to the ecliptic.^[1]

Naming

This minor planet was named after Skuld, one of the three Norns in Norse mythology. The asteroids 167 Urda and 621 Werdandi are named after the other two Norns.^[2] Naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 110).^[2]

Physical characteristics

Rotation period

In January 2004, the first rotational lightcurves of Skuld were obtained by Henk de Groot and by a group of Polish and French astronomers. Lightcurve analysis gave a rotation period of 4.73 and 4.8079 hours with a brightness variation of 0.46 and 0.40 magnitude, respectively (U=2+/3-).^[8][10]

In 2009 and 2011, astronomers Robert Buchheim and Larry Robinson obtained two well-defined lightcurves from photometric observations. They gave a refined period of 4.810 and 4.807 hours with an amplitude of 0.50 and 0.26 magnitude, respectively (U=3/3).^[9][a]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Skuld measures between 9.63 and 11.009 kilometers in diameter and its surface has an albedo between 0.1995 and 0.302.^[4][5][6][7] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of this orbital family – and calculates a diameter of 9.99 kilometers with an absolute magnitude of 12.17.^[3]

Notes

1. Robinson (2011) web: rotation period 4.810 hours with a brightness amplitude of 0.5 mag. Summary figures for (1130) Skuld at 2=Collaborative Asteroid Lightcurve Link (CALL)