| Minorplanet: | yes |
| Background: |
|
| 675 Ludmilla | |
| Mpc Name: | (675) Ludmilla |
| Alt Names: | 1908 DU |
| Discovered: | 30 August 1908 |
| Epoch: | 31 July 2016 (JD 2457600.5) |
| Eccentricity: | 0.20120 |
| Semimajor: | 2.7729AU |
| Perihelion: | 2.215AU |
| Aphelion: | 3.3308abbr=onNaNabbr=on |
| Period: | 4.62 yr (1686.5 d) |
| Inclination: | 9.7796° |
| Asc Node: | 263.200° |
| Arg Peri: | 152.391° |
| Mean Radius: | |
| Mean Motion: | / day |
| Orbit Ref: | [1] |
| Observation Arc: | 98.67 yr (36039 d) |
| Uncertainty: | 0 |
| Abs Magnitude: | 7.91 |
| Rotation: | 7.717abbr=onNaNabbr=on |
675 Ludmilla is a minor planet orbiting the Sun. It was named after Mikhail Glinka's opera Ruslan and Lyudmila.
In 2012, a study by Benoît Carry estimated a mass of for Ludmilla based on its gravitational influence on other Solar System bodies. However, given Ludmilla's diameter of, this mass implies an extremely high density . Such a high density is unphysical, so this mass and density estimate of Ludmilla has been rejected by Carry. Because of Ludmilla's small size, its gravitational influence on other bodies is extremely difficult to detect and may lead to highly inaccurate mass and density estimates. A more recent study in 2019 determined a mass of for Ludmilla, which corresponds to a density of for a diameter of .