694 Ekard
A three-dimensional model of 694 Ekard based on its light curve. | |
Discovery | |
---|---|
Discovered by | Joel Hastings Metcalf |
Discovery site | Taunton, Massachusetts |
Discovery date | November 7, 1909 |
Designations | |
1909 JA | |
Orbital characteristics[1] | |
Epoch August 18, 2005 (JDCT 2453600.5) | |
Aphelion | 3.536 AU |
Perihelion | 1.803 AU |
2.670 AU | |
Eccentricity | 0.325 |
4.362 a | |
17.503° | |
Inclination | 15.842° |
230.429° | |
110.962° | |
Physical characteristics | |
Dimensions | 90.780 km[2] |
5.925[3] | |
Albedo | 0.046[2] |
9.17[2] | |
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694 Ekard is a minor planet orbiting the Sun that was discovered by American astronomer Joel Hastings Metcalf on November 7, 1909.
Photometric observations of this asteroid gave a light curve with a period of 5.925 hours and a brightness variation of 0.50 in magnitude.[3] Measurements of the thermal inertia of 694 Ekard give a value of around 100–140 J m−2 K−1 s−1/2, compared to 50 for lunar regolith and 400 for coarse sand in an atmosphere.[2]
13-cm radar observations of this asteroid from the Arecibo Observatory between 1980 and 1985 were used to produce a diameter estimate of 101 km.[4]
References
- ↑ Yeomans, Donald K., "694 Ekard", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-30.
- 1 2 3 4 Delbo', Marco; Tanga, Paolo (February 2009), "Thermal inertia of main belt asteroids smaller than 100 km from IRAS data", Planetary and Space Science 57 (2), pp. 259–265, arXiv:0808.0869, Bibcode:2009P&SS...57..259D, doi:10.1016/j.pss.2008.06.015.
- 1 2 Zeigler, K. W.; Florence, W. B. (June 1985), "Photoelectric photometry of asteroids 9 Metis, 18 Melpomene, 60 Echo, 116 Sirona, 230 Athamantis, 694 Ekard, and 1984 KD", Icarus 62, pp. 512–517, Bibcode:1985Icar...62..512Z, doi:10.1016/0019-1035(85)90191-5.
- ↑ Ostro, S. J.; et al. (August 1985), "Mainbelt asteroids - Dual-polarization radar observations", Science 229 (4712), pp. 442–446, Bibcode:1985Sci...229..442O, doi:10.1126/science.229.4712.442, PMID 17738665.
External links
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