551 Ortrud

551 Ortrud
Discovery
Discovered by	Max Wolf
Discovery site	Heidelberg
Discovery date	16 November 1904
Designations
Pronunciation	German: [ˈɔʁtʁʊt]
Alternative designations	1904 PM
Orbital characteristics
	Epoch 31 July 2016 (JD 2457600.5)
	Uncertainty parameter 0
Observation arc	111.06 yr (40565 d)
Aphelion	3.3325 AU (498.53 Gm)
Perihelion	2.6019 AU (389.24 Gm)
Semi-major axis	2.9672 AU (443.89 Gm)
Eccentricity	0.12311
Orbital period (sidereal)	5.11 yr (1866.9 d)
Mean anomaly	306.688°
Mean motion	0° 11m 34.188s / day
Inclination	0.39727°
Longitude of ascending node	6.0272°
Argument of perihelion	68.010°
Physical characteristics
Mean diameter	85 ± 11 km; (pole solution 1); 86 ± 10 km; (pole solution 2)
Mass	(5.4±2.5)×1017 kg
Mean density	1.62–1.68 g/cm3 (calculated)
Synodic rotation period	17.41924 ± 0.00003 h; (pole solution 1); 17.41921 ± 0.00002 h; (pole solution 2)
Pole ecliptic longitude	149° ± 35° or 305° ± 30°
Pole ecliptic latitude	−63° ± 9° or −66° ± 8°
Geometric albedo	0.040±0.009
Absolute magnitude (H)	9.79

551 Ortrud is a minor planet orbiting the Sun. It is located in the Main Belt. In light of the practice of the discover c. 1904 to name his asteroids after female characters in opera, it is likely that Ortrud is named after a character in Richard Wagner's opera Lohengrin.

Notes

↑ Calculated from its standard gravitational parameter GM = 0.036±0.017 km³/s².

References

↑ (German Names)
1 2 3 "551 Ortrud (1904 PM)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 5 May 2016.
1 2 3 4 5 6 Marciniak, A.; Ďurech, J.; Choukroun, A.; Hanuš, J.; Ogłoza, W.; Szakáts, R.; Molnár, L.; Pál, A.; Monteiro, F.; Frappa, E.; Beisker, W.; Pavlov, H.; Moore, J.; Adomavičienė, R.; Aikawa, R.; et al. (November 2023). "Scaling slowly rotating asteroids with stellar occultations". Astronomy & Astrophysics. 679: A60. arXiv:2310.08995. Bibcode:2023A&A...679A..60M. doi:10.1051/0004-6361/202346191. ISSN 0004-6361. S2CID 263273956.
↑ Fuentes-Muñoz, Oscar; Farnocchia, Davide; Giorgini, Jon D.; Park, Ryan S. (1 December 2025). "Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release". The Astronomical Journal. 170 (6): 353. Bibcode:2025AJ....170..353F. doi:10.3847/1538-3881/ae0cc9. ISSN 0004-6256. S2CID 283347135.

External links

551 Ortrud at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
551 Ortrud at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

This article about a C-type asteroid native to the asteroid belt is a stub. You can help Wikipedia by adding missing information.

[5] Calculated from its standard gravitational parameter GM = 0.036±0.017 km³/s².

[1] (German Names)

[jpldata-2] 1 2 3 "551 Ortrud (1904 PM)". JPL Small-Body Database. NASA/Jet Propulsion Laboratory. Retrieved 5 May 2016.

[Marciniak2023-3] 1 2 3 4 5 6 Marciniak, A.; Ďurech, J.; Choukroun, A.; Hanuš, J.; Ogłoza, W.; Szakáts, R.; Molnár, L.; Pál, A.; Monteiro, F.; Frappa, E.; Beisker, W.; Pavlov, H.; Moore, J.; Adomavičienė, R.; Aikawa, R.; et al. (November 2023). "Scaling slowly rotating asteroids with stellar occultations". Astronomy & Astrophysics. 679: A60. arXiv:2310.08995. Bibcode:2023A&A...679A..60M. doi:10.1051/0004-6361/202346191. ISSN 0004-6361. S2CID 263273956.

[Fuentes-Muñoz2025-4] Fuentes-Muñoz, Oscar; Farnocchia, Davide; Giorgini, Jon D.; Park, Ryan S. (1 December 2025). "Asteroid Mass Estimation by Mutual Perturbations During Close Encounters After Gaia Focused Product Release". The Astronomical Journal. 170 (6): 353. Bibcode:2025AJ....170..353F. doi:10.3847/1538-3881/ae0cc9. ISSN 0004-6256. S2CID 283347135.