225 Henrietta

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225 Henrietta
Orbital diagram
Discovered byJohann Palisa
Discovery date19 April 1882
(225) Henrietta
Named after
Henrietta Jansen
A882 HA
Main belt (Cybele)
Orbital characteristics[1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc120.87 yr (44,148 d)
Aphelion4.28364 AU (640.823 Gm)
Perihelion2.4945 AU (373.17 Gm)
3.38907 AU (506.998 Gm)
6.24 yr (2,278.9 d)
16.2 km/s
0° 9m 28.703s / day
Physical characteristics
Dimensions120.49±2.5 km
7.3556 h (0.30648 d)

225 Henrietta is a very large outer main-belt asteroid. It was discovered by Austrian astronomer Johann Palisa on April 19, 1882, in Vienna and named after Henrietta, wife of astronomer Pierre J. C. Janssen.[2] The asteroid is orbiting at a distance of 3.39 AU from the Sun with a period of 6.24 years and an eccentricity (ovalness) of 0.26. The orbital plane is inclined at an angle of 20.9° to the plane of the ecliptic.[1] 225 Henrietta belongs to Cybele group of asteroids and is probably in a 4:7 orbital resonance with the planet Jupiter.[3]

This is classified as a C-type asteroid and is probably composed of primitive carbonaceous material. It has a very dark surface, with an albedo of 0.040. Photometric measurements made from the Oakley Southern Sky Observatory during 2012 gave a light curve with a period of 7.352±0.003 h and a variation in brightness of 0.18±0.02 in magnitude. This is consistent with a synodic rotation period of 7.356±0.001 h determined in 2000.[4] In 2001, the asteroid was detected by radar from the Arecibo Observatory at a distance of 1.58 AU. The resulting data yielded an effective diameter of 128±16 km.[5]


  1. ^ a b "225 Henrietta". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 12 May 2016.
  2. ^ Schmadel, Lutz D. (2007). "(225) Henrietta". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 35. doi:10.1007/978-3-540-29925-7_226. ISBN 978-3-540-00238-3.
  3. ^ Kasuga, Toshihiro; et al. (June 2012). "AKARI/AcuA Physical Studies of the Cybele Asteroid Family". The Astronomical Journal. 143 (6): 11. Bibcode:2012AJ....143..141K. doi:10.1088/0004-6256/143/6/141. S2CID 121131179. 141.
  4. ^ Moravec, Patricia; Cochren, Joseph; Gerhardt, Michael; et al. (October 2012), "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2012 January-April", The Minor Planet Bulletin, 39 (4): 213–216, Bibcode:2012MPBu...39..213M.
  5. ^ Magri, Christopher; et al. (January 2007), "A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999 2003" (PDF), Icarus, 186 (1): 126–151, Bibcode:2007Icar..186..126M, doi:10.1016/j.icarus.2006.08.018, retrieved 14 April 2015.

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