249 Ilse

Minor Planet | name=249 Ilse
discoverer=C. H. F. Peters
discovery_date=August 16, 1885
designations=1973 PB
category=Main belt
epoch=30 January, 2005 (JD 2453400.5)
semimajor=355.922 Gm (2.379 AU)
perihelion=279.103 Gm (1.866 AU)
aphelion=432.742 Gm (2.893 AU)
eccentricity=0.216
period=1340.402 d (3.67 a)
inclination=9.629°
asc_node=334.851°
arg_peri=41.91°
mean_anomaly=175.357°
speed=19.31 km/s
dimensions=35.0 km
mass="unknown"
density="unknown"
gravity="unknown"
escape_velocity="unknown"
rotation=85.24 h
spectral_class="unknown"
abs_mag=11.33
albedo=0.043
temperature="unknown"

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. No evidence of it has been provided, however. [http://www.johnstonsarchive.net/astro/asteroidmoonsq.html]

References

* [ftp://ftp.lowell.edu/pub/elgb/astorb.html The Asteroid Orbital Elements Database]
* [http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html Minor Planet Discovery Circumstances]
* [http://spiff.rit.edu/richmond/parallax/phot/LCSUMPUB.TXT Asteroid Lightcurve Data File]