538 Friederike

538 Friederike

Discovery
Discovered by	Paul Götz
Discovery date	July 18, 1904
Designations
Alternative names	1904 OK
Minor planet category	Main belt (Hygiea family)
Orbital characteristics
Epoch 18 August 2005 (JD 2453600.5)
Aphelion	3.680 AU
Perihelion	2.647 AU
Semi-major axis	3.164 AU
Eccentricity	0.163
Orbital period	2055 d (5.63 a)
Average orbital speed	16.64 km/s
Mean anomaly	293.642°
Inclination	6.503°
Longitude of ascending node	141.364°
Argument of perihelion	228.385°
Physical characteristics
Dimensions	72 km[1]
Mass	~2.8×1017 kg (estimate)
Mean density	~1.4 g/cm³ (estimate)[3]
Surface gravity	~0.014 m/s² (estimate)
Escape velocity	~0.032 km/s (estimate)
Rotation period	1.1 d [2]
Albedo	0.0641 [1]
Temperature	~158 K max: 244K (-29° C)
Spectral type	B-type asteroid[4]
Absolute magnitude (H)	9.30

538 Friederike is a minor planet orbiting the Sun.

Photometric observations at the Organ Mesa Observatory in New Mexico during 2012 showed a rotation period of 46.728 ± 0.004 hours with a brightness variation of 0.25 ± 0.02 in magnitude.

References

1. Supplemental IRAS Minor Planet Survey
2. PDS lightcurve data
3. G. A. Krasinsky et al. Hidden Mass in the Asteroid Belt, Icarus, Vol. 158, p. 98 (2002).
4. T. Mothé-Diniz et al. Rotationally Resolved Spectra of 10 Hygiea and a Spectroscopic Study of the Hygiea Family, Icarus, Vol. 152, p. 117 (2001).