Star field showing Hilda (apmag 14.2)
|Discovered by||J. Palisa|
|Discovery date||2 November 1875|
|Main belt (Hilda)|
|Epoch 31 July 2016 (JD 2457600.5)|
|Uncertainty parameter 0|
|Observation arc||121.05 yr (44215 d)|
|Aphelion||4.5341 AU (678.29 Gm)|
|Perihelion||3.4225 AU (512.00 Gm)|
|3.9783 AU (595.15 Gm)|
|7.94 yr (2898.3 d)|
|0° 7m 27.156s / day|
|Earth MOID||2.41154 AU (360.761 Gm)|
|Jupiter MOID||0.569657 AU (85.2195 Gm)|
|Jupiter Tisserand parameter||3.023|
Equatorial escape velocity
|~ 6 m/s|
|5.9587 h (0.24828 d)|
153 Hilda is a large asteroid in the outer main belt, with a diameter of 170 km. Because it is composed of primitive carbonaceous materials, it has a very dark surface. It was discovered by Johann Palisa on November 2, 1875, from the Austrian Naval Observatory at Pula. The name was chosen by the astronomer Theodor von Oppolzer, who named it after one of his daughters.
Orbit and family
Hilda gives its name to an asteroid group called the Hilda family (or Hildas for short). It is not a true asteroid family, since the members are not physically related, but rather share similar orbital elements. The Hildas are locked in a 2:3 orbital resonance with Jupiter; since Jupiter takes 11.9 years to orbit the Sun while Hilda takes 7.9 years, Jupiter orbits the Sun twice for every 3 orbits that Hilda completes. There are over 1,100 other objects known to be in a 2:3 resonance with Jupiter.
- Based on orbital data from the year 2000. Hilda seldom approaches the Lagrangians exactly.
- "JPL Small-Body Database Browser: 153 Hilda". 1998-02-12. Retrieved 12 May 2016.
- Lutz D. Schmadel, Dictionary of Minor Planet Names, p.29.
- Brož, M.; Vokrouhlický, D. (2008). "Asteroid families in the first-order resonances with Jupiter". Monthly Notices of the Royal Astronomical Society. 390 (2): 715–732. Bibcode:2008MNRAS.tmp.1068B. doi:10.1111/j.1365-2966.2008.13764.x.