4197 Morpheus

4197 Morpheus

Discovery[1]
Discovered by	E. F. Helin and E. M. Shoemaker
Discovery date	October 11, 1982
Designations
Alternative names	none
Minor planet category	Apollo, Mars-crosser, Venus-crosser
Orbital characteristics[2]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion	609.578 Gm (4.075 AU)
Perihelion	78.708 Gm (0.526 AU)
Semi-major axis	344.143 Gm (2.300 AU)
Eccentricity	0.771
Orbital period	1274.441 d (3.49 a)
Average orbital speed	16.27 km/s
Mean anomaly	317.807°
Inclination	12.219°
Longitude of ascending node	10.001°
Argument of perihelion	119.441°
Physical characteristics
Dimensions	1.7 km
Mass	~5.1×1012 kg
Mean density	2.0? g/cm³
Equatorial surface gravity	~0.0005 m/s²
Equatorial escape velocity	~0.0009 km/s
Sidereal rotation period	0.147418±0.000002 d (3.53802±0.00005 h)
Axial tilt	?°
Pole ecliptic latitude	?
Pole ecliptic longitude	?
Geometric albedo	0.10?
Temperature	~183 K
Spectral type	?
Absolute magnitude (H)	14.6

4197 Morpheus, provisional designation 1982 TA, is an Apollo, Mars- and Venus-crosser asteroid, only 1.7 km in diameter. It was discovered on October 11, 1982, by American astronomers Eleanor Helin and Eugene Shoemaker.

In 1996, astronomers at the Goldstone Observatory analysed it using radar delay-Doppler imaging. The resultant images are not very clear, but they show that (4197) 1982 TA has a roughly triangular shape, and a 3-hour rotation period.

It's named after Morpheus.