The Maria family (adj. ''Marian'';
FIN
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, or other fluids. Fin ...
:
506
Year 506 (Roman numerals, DVI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Flavius Ennodius Messala, Messala and Areobindus Dagalai ...
; also known as ''Roma family'') is a collisional
asteroid family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An a ...
located in the inner parts of the intermediate
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
, near the 1:3
Kirkwood gap
A Kirkwood gap is a gap or dip in the distribution of the semi-major axes (or equivalently of the orbital periods) of the orbits of main-belt asteroids. They correspond to the locations of orbital resonances with Jupiter.
For example, there ar ...
. The family consist of several thousand stony
S-type asteroid
S-type asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are of this type, making it the second ...
s. It is named after its
parent body
In meteoritics, a parent body is the celestial body from which originates a meteorite or a class of meteorites.
Identification
The easiest way to correlate a meteorite with a parent body is when the parent body still exists. This is the case fo ...
and lowest numbered member, the asteroid
170 Maria.
It is also known as the Roma family, named after its alternative parent body,
472 Roma.
The family was initially identified by Japanese astronomer
Kiyotsugu Hirayama
was a Japanese astronomer, best known for his discovery that many asteroid orbits were more similar to one another than chance would allow, leading to the concept of asteroid families, now called " Hirayama families" in his honour.
Biography
...
in 1918.
Asteroids in this family typically have a
semi-major axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...
between 2.52−2.62
AU, and an
inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...
of 12 to 17
°.
EasySky – Screenshots
/ref>
Members
The family consists of 2940 known members based on the HCM method. Its largest members are the asteroids 170 Maria
Maria (minor planet designation: 170 Maria) is a Asteroid belt, Main belt asteroid that was discovered by French astronomer Henri Joseph Perrotin on January 10, 1877. Its orbit was computed by Antonio Abetti, and the asteroid was named after his ...
and 472 Roma.
Interlopers
Although asteroid 695 Bella
695 Bella is a minor planet orbiting the Sun.
Although this asteroid has dynamic properties that make it a candidate for the Maria family, the spectral properties of the object indicate it is most likely an interloper. Instead, it may have been s ...
has orbital properties that make it a candidate for this family, the spectral properties
In linear algebra, an eigenvector () or characteristic vector of a linear transformation is a nonzero vector that changes at most by a scalar factor when that linear transformation is applied to it. The corresponding eigenvalue, often denoted ...
of the object indicate it is most likely an interloper. Instead, it may have been spalled off from 6 Hebe
Hebe ( minor planet designation: 6 Hebe) is a large main-belt asteroid, containing around 0.5% of the mass of the belt. However, due to its apparently high bulk density (greater than that of the Moon or even Mars), Hebe does not rank among the ...
, or its parent body.
References
{{Small Solar System bodies
*