Discovery | |
---|---|
Discovered by | Max Wolf |
Discovery date | 11 August 1915 |
Designations | |
(809) Lundia | |
Pronunciation | /ˈlʌndiə/ |
Named after | Lund Observatory |
1915 XP; 1936 VC | |
Main belt | |
Orbital characteristics [1] | |
Epoch 31 July 2016 ( JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 100.48 yr (36700 d) |
Aphelion | 2.72316 AU (407.379 Gm) |
Perihelion | 1.84193 AU (275.549 Gm) |
2.28254 AU (341.463 Gm) | |
Eccentricity | 0.19304 |
3.45 yr (1259.6 d) | |
76.7867 ° | |
0° 17m 8.912s / day | |
Inclination | 7.14911° |
154.580° | |
196.162° | |
Physical characteristics | |
Dimensions | 10.26 ± 0.07 km [2] |
Mass | (9.27 ± 3.09) × 1014 kg [2] |
Mean
density | 1.64 ± 0.10 g/cm3 [2] |
15.4142 h (0.64226 d) | |
V | |
12.2 | |
809 Lundia is a small, binary, V-type asteroid [3] orbiting within the Flora family in the main belt. It is named after Lund Observatory, Sweden.
Lundia orbits within the Flora family. However, its V-type spectrum indicates that it is not genetically related to the Flora family, but rather is probably a fragment (two fragments, if its moon is included) ejected from the surface of 4 Vesta by a large impact in the past. Its orbit lies too far from Vesta for it to actually be a member of the Vesta family. It is not clear how it arrived at an orbit so far from Vesta, but other examples of V-type asteroids orbiting fairly far from their parent body are known. A mechanism of interplay between the Yarkovsky effect and nonlinear secular resonances (primarily involving Jupiter and Saturn) has been proposed. [4]
Lightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now refers to one of the objects, the other being provisionally designated S/2005 (809) 1. The similarity of size between the two components is suspected because during mutual occultations the brightness drops by a similar amount independently of which component is hidden. [5] Due to the similar size of the primary and secondary the Minor Planet Center lists this as a binary companion. [6]
Assuming an albedo similar to 4 Vesta (around 0.4) suggests that the components are about 7 km across. They orbit each other in a period of 15.4 hours, [5] which roughly indicates that the separation between them is very close: to the order of 10–20 km if typical asteroid albedo and density values are assumed.
Discovery | |
---|---|
Discovered by | Max Wolf |
Discovery date | 11 August 1915 |
Designations | |
(809) Lundia | |
Pronunciation | /ˈlʌndiə/ |
Named after | Lund Observatory |
1915 XP; 1936 VC | |
Main belt | |
Orbital characteristics [1] | |
Epoch 31 July 2016 ( JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 100.48 yr (36700 d) |
Aphelion | 2.72316 AU (407.379 Gm) |
Perihelion | 1.84193 AU (275.549 Gm) |
2.28254 AU (341.463 Gm) | |
Eccentricity | 0.19304 |
3.45 yr (1259.6 d) | |
76.7867 ° | |
0° 17m 8.912s / day | |
Inclination | 7.14911° |
154.580° | |
196.162° | |
Physical characteristics | |
Dimensions | 10.26 ± 0.07 km [2] |
Mass | (9.27 ± 3.09) × 1014 kg [2] |
Mean
density | 1.64 ± 0.10 g/cm3 [2] |
15.4142 h (0.64226 d) | |
V | |
12.2 | |
809 Lundia is a small, binary, V-type asteroid [3] orbiting within the Flora family in the main belt. It is named after Lund Observatory, Sweden.
Lundia orbits within the Flora family. However, its V-type spectrum indicates that it is not genetically related to the Flora family, but rather is probably a fragment (two fragments, if its moon is included) ejected from the surface of 4 Vesta by a large impact in the past. Its orbit lies too far from Vesta for it to actually be a member of the Vesta family. It is not clear how it arrived at an orbit so far from Vesta, but other examples of V-type asteroids orbiting fairly far from their parent body are known. A mechanism of interplay between the Yarkovsky effect and nonlinear secular resonances (primarily involving Jupiter and Saturn) has been proposed. [4]
Lightcurve observations in 2005 revealed that Lundia is a binary system of two similarly sized objects orbiting their common centre of gravity. "Lundia" now refers to one of the objects, the other being provisionally designated S/2005 (809) 1. The similarity of size between the two components is suspected because during mutual occultations the brightness drops by a similar amount independently of which component is hidden. [5] Due to the similar size of the primary and secondary the Minor Planet Center lists this as a binary companion. [6]
Assuming an albedo similar to 4 Vesta (around 0.4) suggests that the components are about 7 km across. They orbit each other in a period of 15.4 hours, [5] which roughly indicates that the separation between them is very close: to the order of 10–20 km if typical asteroid albedo and density values are assumed.