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(878) Mildred

878 Mildred
Discovery 
Discovered by S. B. Nicholson
H. Shapley
Discovery site Mount Wilson Obs.
Discovery date 6 September 1916
Designations
MPC designation (878) Mildred
1916 f, 1985 VG6, 1991 GZ8
main-belt Nysa
Orbital characteristics
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 99.57 yr (36368 days)
Aphelion 2.8953 AU (433.13 Gm)
Perihelion 1.8286 AU (273.55 Gm)
2.3619 AU (353.34 Gm)
Eccentricity 0.22580
3.63 yr (1325.9 d)
198.89°
0° 16m 17.472s / day
Inclination 2.0648°
172.83°
190.14°
Physical characteristics
Dimensions ~4 km
2.660 h (0.1108 d)
S
14.7

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.

878 Mildred was originally discovered in 1916 using the 1.5 m Hale Telescope at the Mount Wilson Observatory, 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. The asteroid was re-discovered in 1991 by Gareth V. Williams. It is named after Mildred Shapley Matthews.

By comparing the asteroid's perceived brightness and the then computed distance from the Sun they arrived at an absolute visual magnitude of 14.3, which if one assumes Mars-like albedo gives an approximate diameter of 3 to 5 kilometers.



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