89 Julia
![]() VLT-SPHERE image of Julia | |
Discovery | |
---|---|
Discovered by | Édouard Stephan |
Discovery date | 6 August 1866 |
Designations | |
(89) Julia | |
Pronunciation | /ˈdʒuːliə/[1] |
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 | 151.46±3.1 km[2] 147.57 ± 8.32 km[3] |
Mass | (6.71 ± 1.82) × 1018 kg[3] |
Mean density | 3.98 ± 1.27 g/cm3[3] |
11.387 h (0.4745 d)[2] 11.387 ± 0.002 h[4] | |
0.1764±0.007[2] 0.176 [5] | |
S | |
8.74 to 12.61[6] | |
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.
89 Julia is the parent body of the eponymous Julia family of asteroids. Observations of 89 Julia by the VLT's SPHERE instrument tentatively identified a crater 75 km in diameter in the southern hemisphere.[7] The crater was tentatively named Nonza, referring to the commune on the island of Corsica.[8] 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.
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.[4] 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]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/3/38/89Julia_%28Lightcurve_Inversion%29.png/220px-89Julia_%28Lightcurve_Inversion%29.png)
References
- ^ Noah Webster (1884) A Practical Dictionary of the English Language
- ^ a b c d Yeomans, Donald K., "89 Julia", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 13 May 2016.
- ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73 (1): 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
- ^ a b Birlan, Mirel; Barucci, Maria Antonietta; Vernazza, Pierre; Fulchignoni, Marcello; Binzel, Richard P.; Bus, Schelte J.; et al. (June 2004). "Near-IR spectroscopy of asteroids 21 Lutetia, 89 Julia, 140 Siwa, 2181 Fogelin and 5480 (1989YK8), potential targets for the Rosetta mission; remote observations campaign on IRTF". New Astronomy. 9 (5): 343–351. arXiv:astro-ph/0312638. Bibcode:2004NewA....9..343B. doi:10.1016/j.newast.2003.12.005.
- ^ Asteroid Data Sets Archived 2009-12-17 at the Wayback Machine
- ^ "AstDys (89) Julia Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 27 June 2010.
- ^ Vernazza, P.; Broz, M.; Drouard, A. "Astronomy & Astrophysics (A&A)". www.aanda.org. Retrieved 20 December 2019.
- ^ Vernazza, P. "ESO/VLT/SPHERE Survey of D>100km Asteroids : First Results" (PDF). USRA. Retrieved 20 December 2019.
- ^ Ditteon, Richard; Hawkins, Scot (September 2007), "Asteroid Lightcurve Analysis at the Oakley Observatory - October-November 2006", The Minor Planet Bulletin, 34 (3): 59–64, Bibcode:2007MPBu...34...59D, ISSN 1052-8091.
External links
- 89 Julia at AstDyS-2, Asteroids—Dynamic Site
- 89 Julia at the JPL Small-Body Database