| Minorplanet: | yes |
| Mpc Name: | (176) Iduna |
| Background: |
|
| 176 Iduna | |
| Alt Names: | A877 TB; 1945 RQ |
| Discovered: | 14 October 1877 |
| Semimajor: | 3.188AU |
| Perihelion: | 2.6526AU |
| Aphelion: | 3.7235abbr=onNaNabbr=on |
| Period: | 5.69 yr (2079.1 d) |
| Inclination: | 22.660° |
| Eccentricity: | 0.16796 |
| Rotation: | 11.2877abbr=onNaNabbr=on 11.289 hours |
| Abs Magnitude: | 8.2 |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Asc Node: | 200.50° |
| Arg Peri: | 188.17° |
| Mean Motion: | / day |
| Observation Arc: | 138.50 yr (50587 d) |
| Uncertainty: | 0 |
| Moid: | 1.65682AU |
| Jupiter Moid: | 1.73015AU |
| Tisserand: | 3.056 |
176 Iduna is a large main-belt asteroid that was discovered by German-American astronomer Christian Heinrich Friedrich Peters on October 14, 1877, in Clinton, New York. It is named after Sällskapet Idun, a club in Stockholm that hosted an astronomical conference; Idun (Iðunn, Iduna) is also a Norse goddess.[1] [2] A G-type asteroid, it has a composition similar to that of the largest main-belt asteroid, 1 Ceres.
An occultation of a star by Iduna was observed from Mexico on January 17, 1998.
Photometric observations of this asteroid at the Romer Observatory in Aarhus, Denmark during 1996 gave a light curve with a period of 11.289 ± 0.006 hours and a brightness variation of 0.35 in magnitude. A 2008 study at the Palmer Divide Observatory in Colorado Springs, Colorado gave a period of 11.309 ± 0.005 hours, confirming the 1996 result.