809 Lundia facts for kids
| Discovery | |
|---|---|
| Discoverer | Max Wolf |
| Discovery date | August 11, 1915 |
| Alternate designations |
1915 XP; 1936 VC |
| Category | Main belt |
| Orbital elements | |
|
|
|
| Eccentricity (e) | 0.193 |
| Semi-major axis (a) | 341.556 Gm (2.283 AU) |
| Perihelion (q) | 275.743 Gm (1.843 AU) |
| Aphelion (Q) | 407.368 Gm (2.723 AU) |
| Orbital period (P) | 1260.094 d (3.45 a) |
| Mean orbital speed | 19.53 km/s |
| Inclination (i) | 7.143° |
| Longitude of the ascending node (Ω) |
154.685° |
| Argument of perihelion (ω) |
196.321° |
| Mean anomaly (M) | 42.298° |
| Physical characteristics | |
| Dimensions | 7–10 km (estimate) (for each component) |
| Mass | 0.2–2×1015 each (estimate) |
| Density | unknown |
| Surface gravity | 0.001–0.003 m/s² (estimate) |
| Escape velocity | 0.003–0.005 km/s (estimate) |
| Rotation period | unknown |
| Spectral class | V |
| Absolute magnitude | 11.8 |
| Albedo (geometric) | unknown |
| Mean surface temperature |
165-180 K max: 260-280 K |
809 Lundia is a small, binary asteroid that orbits in the Main Belt. It is part of a group called the Flora family. This asteroid is named after the Lund Observatory in Sweden.
Lundia is a special type of asteroid known as a V-type asteroid. This means it likely came from a much larger asteroid named 4 Vesta. Scientists think that Lundia is actually two pieces that broke off Vesta a long time ago because of a big impact. Even though it's a V-type asteroid, its orbit is too far from Vesta for it to be considered part of the Vesta family.
Scientists are still trying to figure out how Lundia ended up so far from Vesta. One idea involves something called the Yarkovsky effect. This effect, along with the pull of giant planets like Jupiter and Saturn, might have slowly pushed Lundia into its current orbit.
What is a Binary Asteroid?
Lundia's Companion
A binary asteroid is like a mini-solar system. It means one asteroid has another, smaller asteroid orbiting around it, much like a moon orbits a planet. In 2005, scientists saw signs that 809 Lundia has its own "moon." This moon is called S/2005 (809) 1.
What's really interesting is that both parts of 809 Lundia seem to be almost the same size. When one body passes in front of the other, blocking its light (this is called a mutual occultation), the brightness of the asteroid drops by a similar amount no matter which one is hidden. This tells us they are very similar in size.
How Big Are They?
Scientists estimate that each part of 809 Lundia is about 7 kilometers (about 4.3 miles) wide. This estimate is based on how much light they reflect, which is called their albedo. If they reflect light like 4 Vesta does, then 7 kilometers is a good guess.
The two parts of 809 Lundia orbit each other quite quickly, taking about 15.4 hours to complete one orbit. This means they are very close together, probably only about 10 to 20 kilometers (6 to 12 miles) apart.
See also
In Spanish: (809) Lundia para niños
