|Properties of the orbit ( animation )|
|Orbit type||Outer main belt|
|Asteroid family||Hilda family|
|Major semi-axis||3,972 AU|
|Perihelion - aphelion||3.423 AU - 4.521 AU|
|Inclination of the orbit plane||7.8 °|
|Length of the ascending node||228.2 °|
|Argument of the periapsis||39.1 °|
|Time of passage of the perihelion||July 16, 2007|
|Sidereal period||7 a 335 d|
|Mean orbital velocity||14.9 km / s|
|Medium diameter||171 km|
|Rotation period||5 h 58 min|
|Absolute brightness||7.48 likes|
|Date of discovery||November 2, 1875|
|Another name||1935 GD|
|Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.|
(153) Hilda is an asteroid of the outer main asteroid belt discovered by Johann Palisa on November 2, 1875 . The celestial body was named in memory of the eldest daughter of the astronomer Theodor von Oppolzer , who had died a year earlier.
Hilda moves between 3.423 ( perihelion ) astronomical units to 4.551 astronomical units ( aphelion ) in 7.96 years around the sun . The orbit is inclined 7.839 ° to the ecliptic , the orbit eccentricity is 0.141.
Star occultation was observed from Japan at the end of 2002 . Hilda passed exactly in front of a star (seen from earth) and darkened its light. Based on the different course of the light curve at different observation points, it could be concluded that Hilda is a round body.
Hilda is the namesake of a group of asteroids that move in an orbital resonance of 3: 2 with the planet Jupiter around the sun. What they have in common is a mean distance from the sun between 3.7 and 4.2 AU, an eccentricity of less than 0.3 and an inclination less than 20 °. If you look at the distribution of the Hilda group, you can see a triangle rotating with Jupiter (which is near the center of one of the edges). This is a dynamic phenomenon that arises from the 3: 2 resonance, because of course none of the asteroids moves on a triangular orbit. But their ellipses are so interwoven in terms of time and space that a triangular distribution of the Hilda group always occurs.
- Lutz D. Schmadel, Dictionary of Minor Planet Names , p.29 .