532 Herculina
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A three-dimensional model of 532 Herculina based on its light curve.
|
|
| Discovery | |
|---|---|
| Discovered by | Max Wolf |
| Discovery date | 20 April 1904 |
| Designations | |
| 1904 NY | |
| Main belt | |
| Orbital characteristics | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 111.97 yr (40897 d) |
| Aphelion | 3.26056 AU (487.773 Gm) |
| Perihelion | 2.28601 AU (341.982 Gm) |
| 2.7732838 AU (414.87735 Gm) | |
| Eccentricity | 0.1757028 |
| 4.62 yr (1686.9 d) (1684.34607 d) |
|
|
Average orbital speed
|
17.65 km/s |
| 131.03906° | |
| 0° 12m 48.272s / day | |
| Inclination | 16.31351° |
| 107.55583° | |
| 76.09745° | |
| Earth MOID | 1.35283 AU (202.380 Gm) |
| Jupiter MOID | 1.96729 AU (294.302 Gm) |
| Jupiter Tisserand parameter | 3.256 |
| Physical characteristics | |
|
Mean radius
|
111.195±2.1 km(IRAS) |
| Mass | ~2.29×1019kg |
|
Mean density
|
~4 g/cm³ |
|
Equatorial surface gravity
|
unknown |
|
Equatorial escape velocity
|
unknown |
| 9.405 h (0.3919 d) | |
| 0.1694±0.007 | |
| Temperature | unknown |
| S | |
| 8.82 to 11.99 | |
| 5.81 | |
| 0.228" to 0.073" | |
532 Herculina (/hɜːrkjʊˈlaɪnə/ HUR-kew-LY-nə) is a large asteroid, with a diameter of around 225 km.
It was discovered on April 20, 1904, by Max Wolf in Heidelberg, and initially catalogued as 1904 NY. The origin of its name is not known; it may be named after the mythical Hercules, or after an unknown woman of that name. The bulk of the asteroids discovered by Wolf around this date were named for characters in operas, but if this name was also drawn from such a source, no explanation has been recorded.
Herculina is one of the larger members of the main asteroid belt. It is believed to rank among the top 20 in size, but the exact dimensions of many large asteroids are still uncertain. The current estimate for its mass would rank it close to the top 10.
It has often been noted for its complex lightcurves, which made determination of its shape and rotation somewhat difficult. A set of 1982 speckle interferometry observations led to a simple preliminary model of Herculina as a three-axis object, perhaps 260 by 220 by 215 km. 1985 analysis of this data concluded there was a nonspherical shape with one bright spot, whilst a 1987 photometric astrometry study concluded the object was spherical with two dark spots (and rotated around a completely different pole), which was in turn negated by a 1988 thermal study which showed the object could not be spherical. By the late 1980s, the generally accepted model was a three-axis object with major albedo or topographical features.
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