Astronomy:69 Hesperia
.png) A three-dimensional model of 69 Hesperia based on its light curve. | |
| Discovery | |
|---|---|
| Discovered by | G. Schiaparelli |
| Discovery date | April 29, 1861[1] |
| Designations | |
| (69) Hesperia | |
| Pronunciation | /hɛˈspɪəriə/[2] |
| Named after | Hesperia |
| Minor planet category | Main belt |
| Adjectives | Hesperian /hɛˈspɪəriən/[3] |
| Orbital characteristics | |
| Epoch (absent) | |
| |{{{apsis}}}|helion}} | 3.471 astronomical unit|AU (519.3 Gm) |
| |{{{apsis}}}|helion}} | 2.489 astronomical unit|AU (372.3 Gm) |
| 2.980 astronomical unit|AU (445.8 Gm) | |
| Eccentricity | 0.165 |
| Orbital period | 1,879 days (5.14 a) |
| Inclination | 8.59° |
| Longitude of ascending node | 184.99° |
| 288.8° | |
| 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] |
| 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 astronomical unit|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
- ↑ 1.0 1.1 "Editorial Notice". The Minor Planet Circulars MPC 94743-95312: 94743. 2015-08-29. https://www.minorplanetcenter.net/iau/ECS/MPCArchive/2015/MPC_20150829.pdf. Retrieved 4 September 2015.
- ↑ Noah Webster (1884) A Practical Dictionary of the English Language
- ↑ Hesperian (3rd ed.), Oxford University Press, September 2005, http://oed.com/search?searchType=dictionary&q=Hesperian (Subscription or UK public library membership required.)
- ↑ 4.0 4.1 4.2 4.3 "JPL Small-Body Database Browser: 69 Hesperia". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=69.
- ↑ 5.0 5.1 5.2 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". Icarus 215 (2): 547–551. doi:10.1016/j.icarus.2011.07.027. Bibcode: 2011Icar..215..547S. http://echo.jpl.nasa.gov/asteroids/MBAs/shepard.etal.2011.angelina+hesperia.pdf.
- ↑ 6.0 6.1 Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: pp. 98–118, doi:10.1016/j.pss.2012.03.009, Bibcode: 2012P&SS...73...98C. 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, pp. 22, ISBN 978-3-540-00238-3, https://books.google.com/books?id=KWrB1jPCa8AC&pg=PA22.
- ↑ 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, doi:10.1016/j.icarus.2004.10.017, Bibcode: 2005Icar..175..141H.
- ↑ Neeley, J. R. et al. (August 2014), "The composition of M-type asteroids II: Synthesis of spectroscopic and radar observations", Icarus 238: 37−50, doi:10.1016/j.icarus.2014.05.008, Bibcode: 2014Icar..238...37N.
External links
- Bareket Observatory (Asteroid 69 Hesperia movie - through an Earth-based telescope.) (in Hebrew)
- 69 Hesperia at AstDyS-2, Asteroids—Dynamic Site
- 69 Hesperia at the JPL Small-Body Database
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