2008 ST291
Encyclopedia
, also written as 2008 ST291, is a trans-Neptunian object
with an absolute magnitude
of 4.4. This makes it a dwarf-planet candidate.
around 1954, and is currently 56.8 AU
from the Sun.
It has only been observed 23 times over three oppositions and has an orbit quality of 4 (0 being best; 9 being worst).
Assuming a generic trans-Neptunian albedo of 0.09, it is about 583 km in diameter. But since its true albedo is unknown and it has an absolute magnitude of 4.4, it could easily be somewhere between 350 to 783 km in diameter.
Trans-Neptunian object
A trans-Neptunian object is any minor planet in the Solar System that orbits the Sun at a greater distance on average than Neptune.The first trans-Neptunian object to be discovered was Pluto in 1930...
with an absolute magnitude
Absolute magnitude
Absolute magnitude is the measure of a celestial object's intrinsic brightness. it is also the apparent magnitude a star would have if it were 32.6 light years away from Earth...
of 4.4. This makes it a dwarf-planet candidate.
Distance
It came to perihelionApsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
around 1954, and is currently 56.8 AU
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
from the Sun.
It has only been observed 23 times over three oppositions and has an orbit quality of 4 (0 being best; 9 being worst).
Assuming a generic trans-Neptunian albedo of 0.09, it is about 583 km in diameter. But since its true albedo is unknown and it has an absolute magnitude of 4.4, it could easily be somewhere between 350 to 783 km in diameter.
External links
- Orbital simulation from JPL (Java) / Horizons Ephemeris