944 Hidalgo
|
|
| Discovery A (http://cfa-www.harvard.edu/iau/lists/NumberedMPs.html) | |
|---|---|
| Discoverer | Walter Baade |
| Discovery date | October 31, 1920 |
| Alternate designations | 1920 HZ B (http://cfa-www.harvard.edu/iau/MPDes.html) |
| Category | Main belt, Jupiter-crosser asteroid, Saturn-crosser asteroid |
| Orbital elements C (http://asteroid.lowell.edu/) Epoch July 14, 2004 (JD 2453200.5) | |
| Eccentricity (e) | 0.660 |
| Semi-major axis (a) | 859.425 Gm (5.745 AU) |
| Perihelion (q) | 291.846 Gm (1.951 AU) |
| Aphelion (Q) | 1427.003 Gm (9.539 AU) |
| Orbital period (P) | 5029.467 d (13.77 a) |
| Mean orbital speed | 12.43 km/s |
| Inclination (i) | 42.567° |
| Longitude of the ascending node (Ω) | 21.549° |
| Argument of perihelion (ω) | 56.569° |
| Mean anomaly (M) | 346.285° |
| Physical characteristics | |
| Dimensions | 20 km |
| Mass | 8.4×1015 kg ??? |
| Density | 2 g/cm³ ??? |
| Surface gravity | 0.0056 m/s² ??? |
| Escape velocity | 0.011 km/s ??? |
| Rotation period | 0.419 29 d[1] (http://www.ipa.nw.ru/PAGE/DEPFUND/LSBSS/parmaeng.htm) |
| Spectral class | D-type asteroid |
| Absolute magnitude | 10.77 |
| Albedo | 0.1 ? |
| Mean surface temperature | ~116 K |
944 Hidalgo is an unusual asteroid, and has the longest orbital period (13.77 years) of any asteroid in the traditional asteroid belt.
With a high eccentricity of 0.66, its perihelion of 1.95 AU takes it to the inner edge of the asteroid belt, while its aphelion of 9.54 AU takes it right out to Saturn's orbit, a characteristic normally associated with Saturn's family of comets. Some astronomers therefore suspect that it was once a comet. Strictly speaking, Hidalgo is a Saturn-grazer rather than a Saturn-crosser as its aphelion does not clear Saturn's. Hidalgo's severe orbital inclination of 43° is suspected to be the result of a close encounter with Jupiter. Its diameter is estimated to be 20 km.
944 Hidalgo was discovered by Walter Baade on October 31, 1920 at Bergedorf Observatory near Hamburg, Germany. German astronomers observed a total eclipse in Mexico on September 10, 1923 and had an audience with the president of Mexico, and in honour of this they named the asteroid after the Mexican hero Miguel Hidalgo y Costilla.
| The minor planets |
| Vulcanoids | Main belt | Groups and families | Near-Earth objects | Jupiter Trojans |
| Centaurs | Trans-Neptunians | Damocloids | Comets | Kuiper belt | Oort cloud |
| (For other objects and regions, see: Binary asteroids, Asteroid moons and the Solar system) |
| (For a complete listing, see: List of asteroids. For pronunciation, see: Pronunciation of asteroid names.) |
da:944 Hidalgo de:Hidalgo (Asteroid) es:(944) Hidalgo fr:(944) Hidalgo