| 词条 | 878 Mildred |
| 释义 |
|minorplanet = yes |name = 878 Mildred |symbol = |background = #D6D6D6 |image = |caption = |discovery_ref = [2] |discoverer = S. B. Nicholson H. Shapley |discovered = 6 September 1916 |discovery_site = Mount Wilson Obs. |mpc_name = (878) Mildred |mp_category = main-belt Nysa [3] |alt_names = 1916 f, {{mp|1985 VG|6}}, {{mp|1991 GZ|8}} |orbit_ref = |epoch = 31 July 2016 (JD 2457600.5) |uncertainty = 0 |observation_arc = 99.57 yr (36368 days) |aphelion = {{Convert|2.8953|AU|Gm|abbr=on|lk=on}} |perihelion = {{Convert|1.8286|AU|Gm|abbr=on}} |semimajor = {{Convert|2.3619|AU|Gm|abbr=on}} |eccentricity = 0.22580 |period = 3.63 yr (1325.9 d) |inclination = 2.0648° |asc_node = 172.83° |mean_anomaly = 198.89° |arg_peri = 190.14° |satellites = |dimensions = ~4 km[5] |mass = |density = |albedo = |rotation = {{Convert|2.660|h|d|abbr=on|lk=on}} |spectral_type = S[3] |abs_magnitude = 14.7 |mean_motion = {{Deg2DMS|0.27152|sup=ms}} / day }}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.[1] The Mildred subgroup, and by extension 878 Mildred itself, is thought to have been formed by a recent fragmentation event from a larger asteroid.[1] Discovery878 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).[2] 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.[3] The asteroid was re-discovered in 1991 by Gareth V. Williams.[4] It is named after Mildred Shapley Matthews. Physical propertiesBy 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.[3] References1. ^1 2 3 {{Cite journal | title = The Puzzling Case of the Nysa–Polana Family | last = Cellino | first = A. | date = August 2001 | journal = Icarus | volume = 152 | issue = 2 | pages = 225–237 | url = https://www.sciencedirect.com/science/article/pii/S0019103501966345| doi = 10.1006/icar.2001.6634 | bibcode=2001Icar..152..225C|display-authors=etal}} 2. ^1 {{Cite journal | title = IAU Circular: IAUC 5275 | date = 1991-05-25 | url = http://www.cfa.harvard.edu/iauc/05200/05275.html}} 3. ^1 2 {{Cite journal | title = The Orbit and Probable Size of a Very Faint Asteroid (878) Mildred | last = Shapley | first = H. |author2= Nicholson, S. B. | year = 1917 | journal = Astronomical Journal | volume = 30 | issue = 710 | pages = 127–128 | bibcode = 1917AJ.....30..127S | doi = 10.1086/104199}} 4. ^{{cite web|title=MPC staff - Gareth Williams|url=http://www.minorplanetcenter.net/about|website=Minor Planet Center|publisher=International Astronomical Union|accessdate=26 August 2014}} }} External links
6 : Nysa asteroids|Discoveries by Seth Nicholson|Discoveries by Harlow Shapley|Minor planets named for people|Named minor planets|Astronomical objects discovered in 1916 |
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