878 Mildred
Encyclopedia
878 Mildred is a minor planet
in the main belt
orbiting the Sun
. It is the lowest numbered, and thus the namesake, of the Mildred family of asteroids, a subgroup of the Nysa family
. The Mildred subgroup, and by extension 878 Mildred itself, is thought to have been formed by a recent fragmentation event from a larger asteroid.
, but was subsequently lost until it was again observed on single nights in 1985 and 1991 (a lost asteroid). Initially only two observations of the asteroid were taken on 1916-09-06 which does not allow for an accurate orbital determination, however interest in the object prompted further investigation and more measurements were taken in late September and October.
of 14.3, which if one assumes Mars-like
albedo gives an approximate diameter of 2 to 3 miles (3.2 to 4.8 km).
Minor planet
An asteroid group or minor-planet group is a population of minor planets that have a share broadly similar orbits. Members are generally unrelated to each other, unlike in an asteroid family, which often results from the break-up of a single asteroid...
in the main belt
Asteroid belt
The asteroid belt is the region of the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets...
orbiting the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
. It is the lowest numbered, and thus the namesake, of the Mildred family of asteroids, a subgroup of the Nysa family
Nysa family
The Nysa or Nysian asteroids are a group of asteroids in the Main Belt orbiting the sun between 2.41 and 2.5 AU. Asteroids in this family have eccentricities between 0.12 and 0.21 and inclinations of 1.4 to 4.3...
. The Mildred subgroup, and by extension 878 Mildred itself, is thought to have been formed by a recent fragmentation event from a larger asteroid.
Discovery
878 Mildred was originally discovered in 1916 using the 1.5 m Hale Telescope at the Mount Wilson ObservatoryMount Wilson Observatory
The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles...
, but was subsequently lost until it was again observed on single nights in 1985 and 1991 (a lost asteroid). Initially only two observations of the asteroid were taken on 1916-09-06 which does not allow for an accurate orbital determination, however interest in the object prompted further investigation and more measurements were taken in late September and October.
Physical properties
By comparing the asteroid's perceived brightness and the then computed distance from the Sun they arrived at an absolute visual magnitudeAbsolute 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 14.3, which if one assumes Mars-like
Mars
Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
albedo gives an approximate diameter of 2 to 3 miles (3.2 to 4.8 km).