153 Hilda
![]() Star field showing Hilda (apmag 14.2) | |
Discovery[1] | |
---|---|
Discovered by | J. Palisa |
Discovery site | Austrian Naval Obs. |
Discovery date | 2 November 1875 |
Designations | |
(153) Hilda | |
Pronunciation | /ˈhɪldə/[2] |
Main belt (Hilda) | |
Adjectives | Hildian /ˈhɪldiən/[3] |
Orbital characteristics[1] | |
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) | |
Eccentricity | 0.13971 |
7.94 yr (2898.3 d) | |
51.690° | |
0° 7m 27.156s / day | |
Inclination | 7.8249° |
228.16° | |
38.617° | |
Jupiter MOID | 0.569657 AU (85.2195 Gm) |
TJupiter | 3.023 |
Physical characteristics | |
Dimensions | 170.63±3.3 km[1] |
Mass | ~5.2×1018 kg |
Equatorial escape velocity | ~ 6 m/s |
5.9587 h (0.24828 d)[1] | |
0.0618±0.002[1] | |
C | |
7.48[1] | |
Hilda (minor planet designation: 153 Hilda) is a large asteroid in the outer main belt, with a diameter of 170 km.[1] 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.[1] The name was chosen by the astronomer Theodor von Oppolzer, who named it after one of his daughters.[4]
Orbit and family
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;[5] since Jupiter takes 11.9 years to orbit the Sun while Hilda takes 7.9 years,[1] 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.[5]
Notes
- ^ Based on orbital data from the year 2000. Hilda seldom approaches the Lagrangians exactly.
References
- ^ a b c d e f g h i "JPL Small-Body Database Browser: 153 Hilda". 12 February 1998. Retrieved 12 May 2016.
- ^ "Hilda". Dictionary.com Unabridged (Online). n.d.
- ^ Bhattacharya & Lichtman (2016) Solar Planetary Systems, p. 6
- ^ Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names. Springer Science & Business Media. p. 29. ISBN 978-3-540-00238-3.
- ^ a b 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.
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External links
- The triangle formed by the Hilda asteroids EasySky
- 153 Hilda at AstDyS-2, Asteroids—Dynamic Site
- 153 Hilda at the JPL Small-Body Database