(341520) Mors
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Asteroid (341520) Mors |
|
|---|---|
| Properties of the orbit ( animation ) | |
| Orbit type | Plutino |
| family | |
| Major semi-axis | 39.01 AU |
| eccentricity | 0.261 |
| Perihelion - aphelion | 28.84 AU - 49.18 AU |
| Inclination of the orbit plane | 11.3 ° |
| Length of the ascending node | 196.8 ° |
| Argument of the periapsis | 205.3 ° |
| Time of passage of the perihelion | May 11, 2017 |
| Sidereal period | 243 a 8 M |
| Mean orbital velocity | 4.686 km / s |
| Physical Properties | |
| Medium diameter | 102 km |
| Dimensions | 7.810 · 10 17 (system) kg |
| Albedo | 0.23 (system) |
| Medium density | 0.75 (system) g / cm³ |
| Rotation period | 9.28 h |
| Absolute brightness | 6.9 (system) mag |
| Spectral class | B-V = 1.29 V-R = 0.74 |
| history | |
| Explorer |
Scott S. Sheppard Chadwick A. Trujillo |
| Date of discovery | October 14, 2007 |
| Another name | 2007 TY 430 |
| 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. | |
(341520) Mors is a Trans-Neptunian object in the Kuiper Belt , which is classified as Plutino . Since Mors has a companion of almost the same size called Somnus , this system is also known as the double asteroid system (341520) Mors-Somnus .
Discovery and naming
Mors was discovered on October 14, 2007 together with Somnus by a team of astronomers from the California Institute of Technology in Pasadena consisting of Scott S. Sheppard and Chadwick A. Trujillo at the Mauna Kea Observatory in Hawaii . The asteroid was given the preliminary designation 2007 TY 430 on October 29, 2012 .
On June 2, 2015, Mors and Somnus received the official name, named after the twin gods of the underworld and descendants of Nox , the goddess of the night from Roman mythology . Mors ( Latin "death") is the Roman personification of death and Somnus (Latin "sleep") that of sleep. The name was assigned under the general rules for Plutinos, who are named after gods of the underworld.
Mors-Somnus was named after Sila-Nunam in January 2012 as the second system of this type, also as a double system, which makes perfect sense due to the proportions of the two bodies. Inconsistently, the L 5 Jupiter Trojan system Patroclus and Menoetius , which have similar proportions, was not given a dual system designation beforehand (see → Nunam: The questions of a not very clear classification of an entire system ).
Since their discovery in 2007, Mors and Somnus have so far (as of January 2018) been observed more than 84 times within 10 years in 7 oppositions.
properties
Orbit
Mors orbits the sun in an elliptical orbit between 28.84 AU and 49.18 AU from its center. The orbit eccentricity is 0.265, the orbit is 11.3 ° inclined to the ecliptic . The orbital period of Mors is 243 years and 8 months. Both MPC and DES classify it as Plutino.
rotation
Mors rotates once around its axis in 9 hours and 16.8 minutes. It follows from this that it performs 232,285 self- rotations ("days") in a Mors year . It can be assumed that his companion Somnus also has its own rotation.
Size and internal structure
The diameter of Mors is 102 km, with its companion Somnus at 97 km, only 4.5% smaller.
The extremely low system density of 0.75 g / cm³, which is far below that of water, indicates that water ice must be predominant on both bodies, which is not sufficient to explain the low density, however, since even pure ice is present 0.91 g / cm³ is even more dense. It can therefore be assumed that both bodies must have cavities inside. (→ Rubble Piles )
surface
Mors and Somnus are two of the reddest Kuiper belt objects ever found. The spectrum shows no significant traces of methane or water ice. The unusually red surface leads to the assumption that Mors and Somnus originated as Cubewanos and only later came into the current orbit resonance with Neptune.
moon
When Mors was discovered, it quickly became apparent that he has a natural companion that is almost the same size. Somnus and Mors orbit the common barycentre in a slightly elliptical orbit at a distance between 17 901 km and 24 179 km from each other, so they are relatively far apart for a double asteroid system. The orbital eccentricity is accordingly 0.1492, the orbital plane of the two components is inclined 15.7 ° with respect to the ecliptic.
See also
Web links
- Mors (2007 TY 430 ) in listing (Distant Minor Planets) of the Minor Planet Center
- How many dwarf planets are there in the outer solar system? Current list of the largest TNOs from Mike Brown
Individual evidence
- ↑ v ≈ π * a / period (1 + sqrt (1-e²))
- ↑ a b A. Thirouin, KS Noll, JL Ortiz, N. Morales: Rotational properties of the binary and non-binary populations in the trans-Neptunian belt . In: Astronomy and Astrophysics . 569, No. A3, September 8, 2014, p. 20. arxiv : 1407.1214 . bibcode : 2014A & A ... 569A ... 3T . doi : 10.1051 / 0004-6361 / 201423567 .
- ^ IAU (MPC) List Of Transneptunian Objects on minorplanetcenter.net
- ↑ (341520) Mors in the Small-Body Database of the Jet Propulsion Laboratory (English). Retrieved January 5, 2018.
- ↑ (341520) Mors at the IAU Minor Planet Center (English) Retrieved January 5, 2018.
- ↑ Brian G. Marsden: MPEC 2009-R09: DISTANT MINOR PLANETS (2009 SEPT 16.0 TT.) . In: IAU Minor Planet Center . March 30, 2009. Retrieved January 5, 2018.
- ^ Marc W. Buie: Orbit Fit and Astrometric record for 341520 . SwRI (Space Science Department). Retrieved January 5, 2018.
- ^ Scott S. Sheppard, Darin Ragozzine, Chadwick Trujillo: 2007 TY430: A Cold Classical Kuiper Belt Type Binary in the Plutino Population . In: The Astronomical Journal . 143, No. 3, February 6, 2012, p. 13. arxiv : 1112.2708 . bibcode : 2012AJ .... 143 ... 58S . doi : 10.1088 / 0004-6256 / 143/3/58 .