69 Hesperia

69 Hesperia
	A three-dimensional model of 69 Hesperia based on its light curve.
Discovery
Discovered by	G. Schiaparelli
Discovery date	April 29, 1861[1]
Designations
MPC designation	(69) Hesperia
Pronunciation	/hɛˈspɪəriə/[2]
Named after	Hesperia
Minor planet category	Main belt
Adjectives	Hesperian /hɛˈspɪəriən/[3]
Orbital characteristics
	Epoch (absent)
Aphelion	3.471 AU (519.3 Gm)
Perihelion	2.489 AU (372.3 Gm)
Semi-major axis	2.980 AU (445.8 Gm)
Eccentricity	0.165
Orbital period	1,879 days (5.14 a)
Inclination	8.59°
Physical characteristics
Dimensions	138 km (IRAS)[4]; 110 ± 15 km[5]
Mass	(5.86±1.18)×1018 kg[6]
Mean density	4.38±0.99 g/cm3[6]
Rotation period	5.655 h[4]
Geometric albedo	0.140[4]
Spectral type	M
Absolute magnitude (H)	7.05[4]

Hesperia (minor planet designation: 69 Hesperia) is a large, M-type main-belt asteroid. It was discovered by the Italian astronomer Giovanni Schiaparelli on April 29, 1861[1] from Milan, while he was searching for the recently discovered 63 Ausonia.[7] It was his only asteroid discovery. Schiaparelli named it Hesperia in honour of Italy (the word is a Greek term for the peninsula).[8] The asteroid is orbiting the Sun with a period of 5.14 years, a semimajor axis of 2.980 AU, and eccentricity of 0.165. The orbital plane is inclined by an angle of 8.59° to the plane of the ecliptic.

Hesperia was observed by Arecibo radar in February 2010.[5] Radar observations combined with lightcurve-based shape models, lead to a diameter estimate of 110 ± 15 km (68 ± 9.3 mi). The radar albedo is consistent with a high-metal M-type asteroid.[5] In the near infrared, a weak absorption feature near a wavelength of 0.9 μm can be attributed to orthopyroxenes on the surface.[9] A meteorite analogue of the reflectance spectra from 69 Hesperia is the Hoba ataxite.[10]

References

"Editorial Notice" (PDF). The Minor Planet Circulars. MPC 94743-95312: 94743. 29 August 2015. Retrieved 4 September 2015.
Noah Webster (1884) A Practical Dictionary of the English Language
"Hesperian". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)
"JPL Small-Body Database Browser: 69 Hesperia" (2011-09-07 last obs). Jet Propulsion Laboratory. Retrieved 27 January 2012.
Shepard, Michael K.; Harris, Alan W.; Taylor, Patrick A.; Clark, Beth Ellen; Ockert-Bell, Maureen; Nolan, Michael C.; et al. (2011). "Radar observations of Asteroids 64 Angelina and 69 Hesperia" (PDF). Icarus. 215 (2): 547–551. Bibcode:2011Icar..215..547S. doi:10.1016/j.icarus.2011.07.027.
Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.
De Meis, S. (2011), "A few aspects of Schiaparelli's studies", Memorie della Societa Astronomica Italiana, 82: 290, Bibcode:2011MmSAI..82..290D.
Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names, Springer Science & Business Media, p. 22, ISBN 978-3-540-00238-3.
Hardersen, Paul S.; et al. (May 2005), "Near-IR spectral evidence for the presence of iron-poor orthopyroxenes on the surfaces of six M-type asteroids", Icarus, 175 (1): 141−158, Bibcode:2005Icar..175..141H, doi:10.1016/j.icarus.2004.10.017.
Neeley, J. R.; et al. (August 2014), "The composition of M-type asteroids II: Synthesis of spectroscopic and radar observations", Icarus, 238: 37−50, arXiv:1407.0750, Bibcode:2014Icar..238...37N, doi:10.1016/j.icarus.2014.05.008.

External links

Bareket Observatory (Asteroid 69 Hesperia movie - through an Earth-based telescope.) (in Hebrew)
69 Hesperia at AstDyS-2, Asteroids—Dynamic Site
- Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
69 Hesperia at the JPL Small-Body Database
- Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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[MPC94743-1] "Editorial Notice" (PDF). The Minor Planet Circulars. MPC 94743-95312: 94743. 29 August 2015. Retrieved 4 September 2015.

[2] Noah Webster (1884) A Practical Dictionary of the English Language

[3] "Hesperian". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005. (Subscription or UK public library membership required.)

[jpldata-4] "JPL Small-Body Database Browser: 69 Hesperia" (2011-09-07 last obs). Jet Propulsion Laboratory. Retrieved 27 January 2012.

[Shepard2011-5] Shepard, Michael K.; Harris, Alan W.; Taylor, Patrick A.; Clark, Beth Ellen; Ockert-Bell, Maureen; Nolan, Michael C.; et al. (2011). "Radar observations of Asteroids 64 Angelina and 69 Hesperia" (PDF). Icarus. 215 (2): 547–551. Bibcode:2011Icar..215..547S. doi:10.1016/j.icarus.2011.07.027.

[Carry2012-6] Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science, 73, pp. 98–118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009. See Table 1.

[DeMeis2011-7] De Meis, S. (2011), "A few aspects of Schiaparelli's studies", Memorie della Societa Astronomica Italiana, 82: 290, Bibcode:2011MmSAI..82..290D.

[Schmadel2003-8] Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names, Springer Science & Business Media, p. 22, ISBN 978-3-540-00238-3.

[Hardersen2005-9] Hardersen, Paul S.; et al. (May 2005), "Near-IR spectral evidence for the presence of iron-poor orthopyroxenes on the surfaces of six M-type asteroids", Icarus, 175 (1): 141−158, Bibcode:2005Icar..175..141H, doi:10.1016/j.icarus.2004.10.017.

[Neeley2014-10] Neeley, J. R.; et al. (August 2014), "The composition of M-type asteroids II: Synthesis of spectroscopic and radar observations", Icarus, 238: 37−50, arXiv:1407.0750, Bibcode:2014Icar..238...37N, doi:10.1016/j.icarus.2014.05.008.