673 Edda

673 Edda is a minor planet orbiting the Sun. It was discovered 20 September 1908 by the American astronomer Joel Hastings Metcalf, and was named for the Norse Edda literary works. The name may also have been inspired by the asteroid's provisional designation 1908 EA.^[3] This asteroid is orbiting at a distance of 2.81 AU with a period of 4.72 yr and an eccentricity of 0.012.^[2] The orbit is close to a 5:2 mean motion resonance with Jupiter, which is located at 2.824 AU.^[4]

673 Edda

Modelled shape of Edda from its lightcurve
Discovery
Discovered by	Joel Hastings Metcalf
Discovery site	Taunton, Massachusetts
Discovery date	20 September 1908
Designations
MPC designation	(673) Edda
Pronunciation	/ˈɛdə/[1]
Alternative designations	1908 EA
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	107.57 yr (39290 d)
Aphelion	2.8471 AU (425.92 Gm)
Perihelion	2.7821 AU (416.20 Gm)
Semi-major axis	2.8146 AU (421.06 Gm)
Eccentricity	0.011542
Orbital period (sidereal)	4.72 yr (1,724.7 d) 4.72 yr (1724.7 d)
Mean anomaly	199.04°
Mean motion	0° 12m 31.428s / day
Inclination	2.8770°
Longitude of ascending node	226.723°
Argument of perihelion	236.303°
Physical characteristics
Mean radius	18.765±0.5 km
Synodic rotation period	22.340 h (0.9308 d)
Geometric albedo	0.1044±0.006
Absolute magnitude (H)	10.20

The long rotation period and low brightness amplitude of this asteroid make it more challenging for measurement of the rotation period. An extensive photometry campaign in 2015 provided a period of 22.340±0.004 h. The unusual light curve suggests that the asteroid shape is very asymmetric.^[5] It is a stony S-type asteroid with a mean diameter of 38+6
−2 km.^[6]