Hilda (minor planet designation: 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 2 November 1875, from the Austrian Naval Observatory at Pula, now Croatia. The name was chosen by the astronomer Theodor von Oppolzer, who named it after one of his daughters.
Star field showing Hilda (apmag 14.2)
|Discovered by||J. Palisa|
|Discovery site||Austrian Naval Obs.|
|Discovery date||2 November 1875|
|MPC designation||(153) Hilda|
|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|
|Jupiter MOID||0.569657 AU (85.2195 Gm)|
Equatorial escape velocity
|~ 6 m/s|
|5.9587 h (0.24828 d)|
Orbit and familyEdit
Hilda gives its name to an asteroid group called the Hilda group (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". 12 February 1998. Retrieved 12 May 2016.
- Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 29. ISBN 978-3-540-00238-3.
- 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. arXiv:1104.4004. Bibcode:2008MNRAS.390..715B. doi:10.1111/j.1365-2966.2008.13764.x.
- The triangle formed by the Hilda asteroids EasySky
- 153 Hilda at AstDyS-2, Asteroids—Dynamic Site
- 153 Hilda at the JPL Small-Body Database