40 Harmonia

40 Harmonia is a large main-belt asteroid. It was discovered by German-French astronomer Hermann Goldschmidt on March 31, 1856,^[6] and named after Harmonia, the Greek goddess of harmony. The name was chosen to mark the end of the Crimean War.

40 Harmonia

A three-dimensional model of 40 Harmonia based on its light curve
Discovery
Discovered by	H. Goldschmidt
Discovery date	March 31, 1856
Designations
MPC designation	(40) Harmonia
Pronunciation	/hɑːrˈmoʊniə/[1]
Named after	Harmonia
Alternative designations	1950 XU
Minor planet category	Main belt
Orbital characteristics[2]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion	355.021 Gm (2.373 AU)
Perihelion	323.537 Gm (2.163 AU)
Semi-major axis	339.279 Gm (2.268 AU)
Eccentricity	0.046
Orbital period (sidereal)	1,247.514 d (3.42 a)
Mean anomaly	249.120°
Inclination	4.256°
Longitude of ascending node	94.287°
Argument of perihelion	268.988°
Physical characteristics
Dimensions	111.251 ± 0.391 km[2]
Mass	(2.206 ± 0.612/0.42)×1018 kg[3]
Mean density	2.867 ± 0.795/0.546 g/cm3[3][lower-alpha 1]
Synodic rotation period	0.3712 d (8.909 h)[4]
Geometric albedo	0.242[5]
Spectral type	S
Apparent magnitude	9.31 (brightest)
Absolute magnitude (H)	6.55[2]

The asteroid is orbiting the Sun with a period of 3.42 years and a relatively low eccentricity of 0.046. It has a cross-sectional size of 107.6 km. The spectrum of 40 Harmonia matches an S-type (silicate) in the Tholen classification system, and is similar to primitive achondrite meteorites.^[7] Photometric observations at the Organ Mesa Observatory in Las Cruces, New Mexico during 2008–09 were used to generate a light curve that showed four unequal minima and maxima per cycle. The curve shows a period of 8.909 ± 0.001 hours with a brightness variation of 0.28 ± 0.02 in magnitude. This result is compatible with previous studies.^[4]

Speckle interferometric observations carried out with the Nicholas U. Mayall Telescope at the Kitt Peak National Observatory during 1982–84 failed to discover a satellite companion.^[8] In 1988 a search for satellites or dust orbiting this asteroid was performed using the UH88 telescope at the Mauna Kea Observatories, but the effort came up empty.^[9]

Notes

1. Assuming a diameter of 113.7 ± 7 km.

References

1. Noah Webster (1884) A Practical Dictionary of the English Language
2. Yeomans, Donald K., "40 Harmonia", JPL Small-Body Database Browser, NASA Jet Propulsion Laboratory, retrieved 7 April 2013.
3. Fienga, A.; Avdellidou, C.; Hanuš, J. (February 2020). "Asteroid masses obtained with INPOP planetary ephemerides". Monthly Notices of the Royal Astronomical Society. 492 (1). doi:10.1093/mnras/stz3407.
4. Pilcher, Frederick (October 2009), "New Lightcurves of 8 Flora, 13 Egeria, 14 Irene, 25 Phocaea 40 Harmonia, 74 Galatea, and 122 Gerda", The Minor Planet Bulletin, vol. 36, no. 4, pp. 133–136, Bibcode:2009MPBu...36..133P.
5. Asteroid Data Archive, Planetary Science Institute, archived from the original on 23 June 2006, retrieved 3 November 2008.
6. "Numbered Minor Planets 1–5000", Discovery Circumstances, IAU Minor Planet center, retrieved 7 April 2013.
7. Hiroi, T.; et al. (March 1993), "Modeling of S-type asteroid spectra using primitive achondrites and iron meteorites", Icarus, vol. 102, no. 1, pp. 107–116, Bibcode:1993Icar..102..107H, doi:10.1006/icar.1993.1036.
8. Roberts, Lewis C. Jr.; et al. (November 1995), "A Speckle Interferometric Survey for Asteroid Duplicity", Astronomical Journal, vol. 110, pp. 2463–2468, Bibcode:1995AJ....110.2463R, doi:10.1086/117704.
9. Gradie, J.; Flynn, L. (March 1988), "A Search for Satellites and Dust Belts Around Asteroids: Negative Results", Abstracts of the Lunar and Planetary Science Conference, vol. 19, pp. 405–406, Bibcode:1988LPI....19..405G.

External links

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