249 Ilse

249 Ilse

Discovery
Discovered by	C. H. F. Peters
Discovery date	August 16, 1885
Designations
Alternative names	1973 PB
Minor planet category	Main belt
Orbital characteristics
Epoch 30 January 2005 (JD 2453400.5)
Aphelion	432.742 Gm (2.893 AU)
Perihelion	279.103 Gm (1.866 AU)
Semi-major axis	355.922 Gm (2.379 AU)
Eccentricity	0.216
Orbital period	1340.402 d (3.67 a)
Average orbital speed	19.31 km/s
Mean anomaly	175.357°
Inclination	9.629°
Longitude of ascending node	334.851°
Argument of perihelion	41.91°
Physical characteristics
Dimensions	35.0 km
Mass	unknown
Mean density	unknown
Surface gravity	unknown
Escape velocity	unknown
Rotation period	85.24 h
Albedo	0.043
Temperature	unknown
Spectral type	unknown
Absolute magnitude (H)	11.33

249 Ilse is a Main belt asteroid. It has an unusually slow rotation period, about 3.5 days.

It was discovered by C. H. F. Peters on August 16, 1885 in Clinton, New York and was named after Ilse, a legendary German princess.

Due to the long rotation period, a possible asteroidal satellite of Ilse was proposed by R. P. Binzel in 1987 however no evidence of this has been found.^[1]

References

1. Johnston, Robert. "Other Reports of Asteroid/TNO Companions (Updated 13 July 2013)". Retrieved 19 November 2013.

• The Asteroid Orbital Elements Database
• Minor Planet Discovery Circumstances
• Asteroid Lightcurve Data File

External links

• 249 Ilse at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters