, provisional designation , is a
binary
Binary may refer to:
Science and technology Mathematics
* Binary number, a representation of numbers using only two digits (0 and 1)
* Binary function, a function that takes two arguments
* Binary operation, a mathematical operation that t ...
and
plutino
In astronomy, the plutinos are a dynamical group of trans-Neptunian objects that orbit in 2:3 mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the lar ...
. It consists of two components less than 60 kilometers in diameter, orbiting at a distance of 21000 km.
Mors–Somnus was discovered on 14 October 2007, by American astronomers
Scott Sheppard
Scott Sander Sheppard (born 1977) is an American astronomer and a discoverer of numerous moons, comets and minor planets in the outer Solar System.
He is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Scie ...
and
Chad Trujillo
Chadwick A. Trujillo (born November 22, 1973) is an American astronomer, discoverer of minor planets and the co-discoverer of Eris, the most massive dwarf planet known in the Solar System.
Trujillo works with computer software and has examined ...
with the
Subaru telescope
is the telescope of the National Astronomical Observatory of Japan, located at the Mauna Kea Observatory on Hawaii. It is named after the open star cluster known in English as the Pleiades. It had the largest monolithic primary mirror in the wo ...
at
Mauna Kea Observatories
The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located ...
in Hawaii, United States. It was later named after the twins
Mors and
Somnus
In Roman mythology, Somnus ("sleep") is the personification of sleep. His Greek counterpart is Hypnos. Somnus resided in the underworld. According to Virgil, Somnus was the brother of Death (Mors (mythology), Mors), and according to Ovid, Somnus ...
from Roman mythology.
Orbit and binarity
''Mors–Somnus'' is a small double
plutino
In astronomy, the plutinos are a dynamical group of trans-Neptunian objects that orbit in 2:3 mean-motion resonance with Neptune. This means that for every two orbits a plutino makes, Neptune orbits three times. The dwarf planet Pluto is the lar ...
occupying the 3:2 mean motion resonance with
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times ...
.
The object is a wide optically resolved binary with the following orbital parameters:
The components has almost equal size.
Physical properties
The total mass of the system is . For a realistic minimal density of 0.5 g/cm
3 the
albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
is >0.17 and the size of the components is <60 km.
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.1 and calculates a diameter of 175.20 kilometers based on an
absolute magnitude
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...
of 6.9.
''Mors–Somnus'' has an ultra-red spectrum in the visible and near-infrared parts of the spectrum. The colors of two components are indistinguishable from each other.
It demonstrates a double-peaked light curve with the period of about 9.28 hours and amplitude of 0.24. This indicates that either primary of secondary has an elongated shape and rotates non-synchronuosly.
Evolution
The ''Mors–Somnus'' system is likely to be an escaped
cold classical Kuiper belt object.
Naming
The
minor planet
According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...
was named after the mythological twin Roman gods of death (
Mors) and sleep (
Somnus
In Roman mythology, Somnus ("sleep") is the personification of sleep. His Greek counterpart is Hypnos. Somnus resided in the underworld. According to Virgil, Somnus was the brother of Death (Mors (mythology), Mors), and according to Ovid, Somnus ...
).
The approved naming citation was published by the
Minor Planet Center
The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory.
Function
...
on 2 June 2015 ().
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Minor Planet Center
*
*
{{DEFAULTSORT:Mors-Somnus
341520
Discoveries by Scott S. Sheppard
Discoveries by Chad Trujillo
Named minor planets
Binary trans-Neptunian objects
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