Discovery | |
---|---|
Discovered by | Édouard Stephan |
Discovery date | 6 August 1866 |
Designations | |
(89) Julia | |
Pronunciation | /ˈdʒuːliə/ [1] |
Named after | Julia of Corsica |
Main belt | |
Adjectives | Julian /ˈdʒuːliən/ |
Orbital characteristics [2] | |
Epoch 31 July 2016 ( JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 149.68 yr (54672 d) |
Aphelion | 3.0202 AU (451.82 Gm) |
Perihelion | 2.08017 AU (311.189 Gm) |
2.55016 AU (381.499 Gm) | |
Eccentricity | 0.18430 |
4.07 yr (1487.5 d) | |
255.367 ° | |
0° 14m 31.272s / day | |
Inclination | 16.128° |
311.563° | |
45.461° | |
Physical characteristics | |
Dimensions | c/a = 0.70±0.03
[3] (89±2)×(80±1)×(62±3) km [4] |
140±3
km
[4]
[3] 151±3 km [2] 148±8 km [5] | |
Mass | (4.3±3.2)×1018 kg
[3] (4.3±3.6)×1018 kg [4] (6.7±1.8)×1018 kg [5] |
Mean
density | 3.0±2.2 g/cm3
[3] 3.0±2.6 g/cm3 [4] 4.0±1.3 g/cm3 [5] |
11.388336±0.000001 h (0.4745 day) [4] | |
0.216 (calculated)
[3] 0.1764±0.007 [2] 0.176 [6] | |
S | |
8.74 to 12.61 [7] | |
6.60 | |
0.18" to 0.052" | |
Julia ( minor planet designation: 89 Julia) is a large main-belt asteroid that was discovered by French astronomer Édouard Stephan on August 6, 1866. This was first of his two asteroid discoveries; the other was 91 Aegina. 89 Julia is believed to be named after Saint Julia of Corsica. A stellar occultation by Julia was observed on December 20, 1985.
The spectrum of 89 Julia shows the signature of silicate rich minerals with possible indications of an abundant calcic clinopyroxene component. It is classified as an S-type asteroid. The asteroid has an estimated diameter of 151.4±3.1 km. [8] Photometry from the Oakley Observatory during 2006 produced a lightcurve that indicated a sidereal rotation period of 11.38±0.01 with an amplitude of 0.20±0.02 in magnitude. [9]
89 Julia is the parent body of the eponymous Julia family of asteroids. Observations of 89 Julia by the VLT's SPHERE instrument identified a 'highly probable' crater 70–80 km in diameter and 4.1±1.7 km deep in the southern hemisphere as the only visible possible source of the family. [10] The crater was named Nonza by the discoverers, referring to the commune on the island of Corsica where Saint Julia was born. [11] The excavated volume is on the order of 5,000 to 15000 km3. It is hypothesized an impact 30 to 120 million years ago by another body approximately 8 kilometers in diameter may have created the collisional family.
Discovery | |
---|---|
Discovered by | Édouard Stephan |
Discovery date | 6 August 1866 |
Designations | |
(89) Julia | |
Pronunciation | /ˈdʒuːliə/ [1] |
Named after | Julia of Corsica |
Main belt | |
Adjectives | Julian /ˈdʒuːliən/ |
Orbital characteristics [2] | |
Epoch 31 July 2016 ( JD 2457600.5) | |
Uncertainty parameter 0 | |
Observation arc | 149.68 yr (54672 d) |
Aphelion | 3.0202 AU (451.82 Gm) |
Perihelion | 2.08017 AU (311.189 Gm) |
2.55016 AU (381.499 Gm) | |
Eccentricity | 0.18430 |
4.07 yr (1487.5 d) | |
255.367 ° | |
0° 14m 31.272s / day | |
Inclination | 16.128° |
311.563° | |
45.461° | |
Physical characteristics | |
Dimensions | c/a = 0.70±0.03
[3] (89±2)×(80±1)×(62±3) km [4] |
140±3
km
[4]
[3] 151±3 km [2] 148±8 km [5] | |
Mass | (4.3±3.2)×1018 kg
[3] (4.3±3.6)×1018 kg [4] (6.7±1.8)×1018 kg [5] |
Mean
density | 3.0±2.2 g/cm3
[3] 3.0±2.6 g/cm3 [4] 4.0±1.3 g/cm3 [5] |
11.388336±0.000001 h (0.4745 day) [4] | |
0.216 (calculated)
[3] 0.1764±0.007 [2] 0.176 [6] | |
S | |
8.74 to 12.61 [7] | |
6.60 | |
0.18" to 0.052" | |
Julia ( minor planet designation: 89 Julia) is a large main-belt asteroid that was discovered by French astronomer Édouard Stephan on August 6, 1866. This was first of his two asteroid discoveries; the other was 91 Aegina. 89 Julia is believed to be named after Saint Julia of Corsica. A stellar occultation by Julia was observed on December 20, 1985.
The spectrum of 89 Julia shows the signature of silicate rich minerals with possible indications of an abundant calcic clinopyroxene component. It is classified as an S-type asteroid. The asteroid has an estimated diameter of 151.4±3.1 km. [8] Photometry from the Oakley Observatory during 2006 produced a lightcurve that indicated a sidereal rotation period of 11.38±0.01 with an amplitude of 0.20±0.02 in magnitude. [9]
89 Julia is the parent body of the eponymous Julia family of asteroids. Observations of 89 Julia by the VLT's SPHERE instrument identified a 'highly probable' crater 70–80 km in diameter and 4.1±1.7 km deep in the southern hemisphere as the only visible possible source of the family. [10] The crater was named Nonza by the discoverers, referring to the commune on the island of Corsica where Saint Julia was born. [11] The excavated volume is on the order of 5,000 to 15000 km3. It is hypothesized an impact 30 to 120 million years ago by another body approximately 8 kilometers in diameter may have created the collisional family.