(283) Emma
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Asteroid (283) Emma |
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|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | Outer main belt |
| family | Emma family |
| Major semi-axis | 3.0516 AU |
| eccentricity | 0.1460 |
| Perihelion - aphelion | 2.6060 AU - 3.4972 AU |
| Inclination of the orbit plane | 7.977 ° |
| Length of the ascending node | 304.248 ° |
| Argument of the periapsis | 54.055 ° |
| Time of passage of the perihelion | January 12, 2020 |
| Sidereal period | 5 a 122 d |
| Mean orbital velocity | 17.07 km / s |
| Physical Properties | |
| Medium diameter | 132.4 ± 0.3 km |
| Dimensions | 3.80 ± 0.03 x 10 18 kg |
| Albedo | 0.032 ± 0.004 |
| Medium density | 0.81 ± 0.08 g / cm³ |
| Rotation period | 6 h 53 min 17 s |
| Absolute brightness | 8.72 likes |
| Spectral class | X |
| history | |
| Explorer | Auguste H. P. Charlois |
| Date of discovery | February 8, 1889 |
| Another name | 1980 FJ12 |
| Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items. | |
(283) Emma is an asteroid of the main outer asteroid belt . With a diameter of 132 km, it is one of the larger asteroids of the main belt and it has a moon named S / 2003 (283) 1 .
Discovery and naming
Emma was discovered on February 8, 1889 by the French astronomer Auguste Honoré Pierre Charlois at the Observatoire de Nice in Nice ( France ). The origin of the name is unclear.
In total, the asteroid has been observed through several earth-based telescopes, a total of 2265 times within 123 years. (As of Sept. 2017)
Track properties
Orbit
Emma orbits the sun in a prograde , elliptical orbit between 389,850,000 km (2.61 AU ) and 523,180,000 km (3.50 AU) from its center. The orbital eccentricity is 0.146, the web is about 7.98 ° relative to the ecliptic inclined . Its orbit is therefore in the outer asteroid belt .
The orbital period of Emma is 5.33 years.
rotation
Emma rotates once around her axis in 6 hours, 53 minutes 17 seconds. From this it follows that the asteroid performs 6,784.5 self- rotations ("days") in an Emma year .
Emma family
(283) Emma is the namesake of an asteroid family with similar orbital elements and a predominantly similar mineralogical composition.
Physical Properties
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size
The observations made so far indicate an irregularly shaped body; the most precise determination of the diameter ( geometric mean ) is 132.385 km. The exact dimensions are currently unclear.
Assuming a mean diameter of 132.4 km, the surface area is around 55,000 km 2 , which is just below the area of Croatia .
Provisions of the diameter for Emma
| year | Dimensions km | source |
|---|---|---|
| 200? | 145.70 ± 5.89 | IRAS |
| 2002 | 148.06 ± 4.60 | Tedesco ( IRAS ) et al. |
| 200? | 145.44 ± 7.72 | ( Sharpener ) |
| 2008 | 160 ± 10 | Marchis et al. |
| 2011 | 134.70 ± 2.35 | Masiero et al. |
| 2012 | 148.00 ± 16.26 | Ryan (Spitzer) et al. |
| 2014 | 132.385 ± 0.258 | Masiero et al. |
The most precise / most recent determination is marked in bold .
internal structure
Emma belongs to the X-type asteroids (according to other classifications: P) and therefore has a very dark, carbon-rich surface with an albedo of 0.032; it may consist of primitive carbonaceous chondrites . The density is 0.8 g / cm 3 - lower than the density of water - which could be an indication that it is not a compact body, but rather a rubble pile , a collection of dust and rocks that is riddled with cavities.
So far, the mass has been calculated to be 3.8 ∙ 10 18 . The mean surface temperature is 184 K (−89 ° C).
moon
On July 14, 2003, a team of astronomers from the Mauna Kea Observatory discovered a moon Emma with the help of the Keck II telescope , which was given the provisional designation S / 2003 (283) 1 . The companion was confirmed two days later by employees of the ESO Very Large Telescope . The moon has a diameter of 9 kilometers and orbits Emma in 3.35 days at a distance of 581 km.
The Emma system at a glance:
| Components | Physical parameters | Path parameters | discovery | |||||
|---|---|---|---|---|---|---|---|---|
| Surname | Throughput diameter (km) |
Relative size % |
Mass (kg) |
Major semi-axis (km) |
Orbital time (d) |
eccentricity |
Inclination to Emma's equator |
Date of discovery Date of publication |
|
(283) Emma |
132.4 | 100.00 | 3.8 · 10 18 | - | - | - | - | February 8, 1889 1889 |
|
S / 2003 (283) 1 (Emma I) |
9.0 | 6.8 | ? | 581 | 3.353 | 0.12 | 94.2 ° | July 14, 2003 July 27, 2003 |
See also
Web links
- Wm. Robert Johnston: (283) Emma and S / 2003 (283) 1 (English)
- Michalowski et al .: Asteroid (283) Emma Rotatable 3D model of Emma (English)
- Asteroid Emma: Discovery Circumstances according to the Minor Planet Center of the International Astronomical Union at the Harvard-Smithsonian Center for Astrophysics, Cambridge, USA (English)
Individual evidence
- ↑ (283) Emma in the Small-Body Database of the Jet Propulsion Laboratory (English).
- ↑ a b IRAS (2002): IRAS Minor Planet Survey V. 6.0. Retrieved September 12, 2017 .
- ^ Franck Marchis et al .: Main belt binary asteroidal systems with eccentric mutual orbits . May 2008, bibcode : 2008Icar..195..295M .
- ^ Joseph R. Masiero et al .: Main Belt Asteroids with WISE / NEOWISE I: Preliminary Albedos and Diameters . September 2011, arxiv : 1109.4096 .
- ↑ Erin Lee Ryan et al .: The Kilometer-Sized Main Belt Asteroid Population as Revealed by Spitzer . April 2012, bibcode : 2012arXiv1204.1116R .
- ↑ Joseph R. Masiero et al .: Main-belt Asteroids with WISE / NEOWISE: Near-infrared Albedos . August 2014, bibcode : 2014ApJ ... 791..121M .
- ↑ Daniel WE Green: IAUC No. 8165: S / 2003 (283) 1 discovery publication (July 2003). Retrieved September 12, 2017 .