| Minorplanet | yes |
|---|---|
| Background |
|
| Mpc name | (522) Helga |
| Pronounced | ˈhɛlɡaː[1] |
| Alt names | 1904 NC |
| Discoverer | Max Wolf |
| Discovered | 10 January 1904 |
| Discovery site | Heidelberg Observatory |
| Epoch | 31 July 2016 (JD 2457600.5) |
| Eccentricity | 0.083794 |
| Semimajor | 3.6328 AU (543.46 Gm) |
| Perihelion | 3.3284 AU (497.92 Gm) |
| Aphelion | 3.9372 AU (589.00 Gm) |
| Period | 6.92 yr (2529.1 d) |
| Inclination | 4.4174° |
| Asc node | 116.683° |
| Arg peri | 246.503° |
| Mean anomaly | 200.06° |
| Mean motion | / day |
| Observation arc | 114.65 yr (41876 d) |
| Uncertainty | 0 |
| Abs magnitude | 9.0 |
| Rotation | 8.129 h |
| Albedo | 0.0388 ± 0.003 |
| Mean radius | 50.61 ± 1.75 km |
522 Helga, provisional designation 1904 NC is a large main belt asteroid (minor planet). It was discovered in 1904 by Max Wolf in Heidelberg. Helga is notable for being the first such object to be shown to be in a stable but chaotic orbit in a 7:12 resonance with Jupiter, its Lyapunov time being relatively short, at 6,900 yr. Despite this, its orbit appears to be stable, as the eccentricity and precession rates are such that it avoids close encounters with Jupiter.[2] It forms part of the Cybele asteroid group.[3]
522 Helga was "named by Lt. Th. Lassen, orbit computer" according to Paul Herget's The Names of the Minor Planets[4] (note that computer does not refer to a personal computer, i.e. a machine, but rather to a person actually doing the necessary calculations).
References
- ^ (German Names)
- ^ Milani, Andrea & Nobili, Anna M. (June 1992). "An example of stable chaos in the Solar System". Nature. 357 (6379): 569–571. Bibcode:1992Natur.357..569M. doi:10.1038/357569a0. ISSN 1476-4687. S2CID 4367823
- ^ Lagerkvist, Claes-Ingvar et al. (January 2001), "A Study of Cybele Asteroids. I. Spin Properties of Ten Asteroids", Icarus. 149 (1): 190–197, Bibcode:2001Icar..149..190L. doi:10.1006/icar.2000.6507
- ^ Title: Benennung von kleinen Planeten; Journal: Astronomische Nachrichten, volume 169, p.363; Bibliographic Code: 1905AN....169..363.