The Nysa family (adj. ''Nysian'';
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 ...
:
405
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Year 405 ( CDV) 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 Stilicho and Anthemius (or, less frequently, year 1158 ''Ab ...
) is part of the Nysa–Polana complex, the largest cluster of
asteroid families in the
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, c ...
.
It is located in the
inner region of the asteroid belt, orbiting the Sun between 2.41 and 2.5
AU. Asteroids in this complex have
eccentricities between 0.12 and 0.21 and
inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object.
For a satellite orbiting the Eart ...
s of 1.4 to 4.3. The family derives its name from its most massive member,
44 Nysa
Nysa (minor planet designation: 44 Nysa) is a large and very bright main-belt asteroid, and the brightest member of the Nysian asteroid family. It is classified as a rare class E asteroid and is probably the largest of this type (though 55 Pand ...
. It has also been known as the Hertha family ''(adj. Herthian)'' named after
135 Hertha.
Subdivision
Asteroids in this complex are typically divided into the stony Nysa and carbonaceous Polana subgroups, two mineralogically different families:
* The much brighter
S-type Nysian subgroup (i.e. the Nysa family, in the narrower sense) includes
44 Nysa and
135 Hertha
Hertha (minor planet designation: 135 Hertha) is an asteroid from the inner region of the asteroid belt, approximately in diameter. Discovered on 18 February 1874 by German–American astronomer Christian Peters at the Litchfield Observatory ne ...
.
* In the low-
albedo
Albedo (; ) is the measure of the diffuse reflection of 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 that refl ...
subgroup of the complex lies the Polana family ''(adj Polanian)'', a family of dark
F-type asteroid
F-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group.
Characteristics
F-type asteroids have spectra generally similar to those of the B-type asteroids, but
lack the "water" absorption feature ar ...
s named after
142 Polana
Polana ( minor planet designation: 142 Polana) is a very dark asteroid from the asteroid belt. It was discovered by Johann Palisa on January 28, 1875, and named after the city of Pola (now Pula, Croatia), home of the Austrian Naval Observato ...
, the largest asteroid in this section.
More recently an additional family, the Eulalia family has also been identified inside this subgroup.
Nysian asteroids
See also
*
101955 Bennu
101955 Bennu (provisional designation ) is a carbonaceous asteroid in the Apollo group discovered by the LINEAR Project on 11 September 1999. It is a potentially hazardous object that is listed on the Sentry Risk Table and has the highest cumul ...
, probably part of the Polana family, visited by the
OSIRIS-REx
OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer) is a NASA asteroid-study and sample-return mission. The mission's primary goal is to obtain a sample of at least from 101955 Bennu, a carbona ...
spacecraft in 2018
References
}
{{Small Solar System bodies
*