225 Henrietta

Infobox Planet | discovery=yes | physical_characteristics = yes | bgcolour=#FFFFC0 | name=225 Henrietta
discoverer=Johann Palisa
discovered=April 19, 1882
alt_names="n/a"
mp_category=Main belt (Cybele)
epoch=30 January, 2005 (JD 2453400.5)
semimajor=505.966 Gm (3.382 AU)
perihelion=370.46 Gm (2.476 AU)
aphelion=641.471 Gm (4.288 AU)
eccentricity=0.268
period=2271.87 d (6.22 a)
inclination=20.902°
asc_node=197.199°
arg_peri=104.697°
mean_anomaly=215.046°
avg_speed=16.2 km/s
dimensions=121.0 km
mass="unknown"
density="unknown"
surface_grav="unknown"
escape_velocity="unknown"
rotation=7.356 h
spectral_type=C
abs_magnitude=8.72
albedo=.040
single_temperature="unknown"

225 Henrietta is a very large outer Main belt asteroid. It is classified as a C-type asteroid and is probably composed of privitive carbonaceous material. It has very dark surface.

It belongs to Cybele group of asteroids and is probably in 4:7 orbital resonance with planet Jupiter.

It was discovered by Johann Palisa on April 19, 1882 in Vienna and named after Henrietta, wife of astronomer Pierre J. C. Janssen.

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]