25 Phocaea

25 Phocaea

A three-dimensional model of 25 Phocaea based on its light curve.
Discovery
Discovered by J. Chacornac
Discovery date April 6, 1853
Designations
Pronunciation /foʊˈsiːə/ foh-SEE-ə
Named after
 Phōcæa
1956 GC
Main belt (Phocaea family)
Orbital characteristics
Epoch June 14, 2006 (JD 2453900.5)
Aphelion 450.716 Gm (3.013 AU)
Perihelion 267.314 Gm (1.787 AU)
359.015 Gm (2.400 AU)
Eccentricity 0.255
1357.936 d (3.72 a)
18.91 km/s
6.932°
Inclination 21.584°
214.258°
90.154°
Physical characteristics
Dimensions 75.1 ± 3.6 km (IRAS)[1]
80.19 ± 4.66[2] km
Mass (5.99 ± 0.60) × 1017 kg[2]
Mean density
 2.21 ± 0.44[2] g/cm3
0.0210? m/s²
0.0397? km/s
0.4144 d (9.945 h)[1][3]
Albedo 0.231[1][4]
Temperature ~173 K
Spectral type
 S[1]
7.83[1]

    25 Phocaea is a main-belt asteroid. It was discovered by J. Chacornac at Marseille, on April 6. 1853. It was his first asteroid discovery out of a total of six. It is named after Phocaea, the Greek name of Foça in Turkey, whence the founders of Marseille came.

    Phocaea has been studied by radar.[5] Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico during 2010 gave a light curve with a period of 9.9341 ± 0.0002 hours. The brightness near the deepest minimum of the light curve showed changes with phase angle, which is the result of shadows extending across surface irregularities.[6]

    References

    1. 1 2 3 4 5 "JPL Small-Body Database Browser: 25 Phocaea" (2011-12-30 last obs). Jet Propulsion Laboratory. Retrieved 2012-01-26.
    2. 1 2 3 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.
    3. ↑ http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_DERIVED_LIGHTCURVE_V8_0/data/lc.tab
    4. ↑ http://www.psi.edu/pds/asteroid/EAR_A_5_DDR_ALBEDOS_V1_1/data/albedos.tab
    5. ↑ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 2011-10-30.
    6. ↑ Pilcher, Frederick (April 2011), "Rotation Period Determinations for 25 Phocaea, 140 Siwa, 149 Medusa 186 Celuta, 475 Ocllo, 574 Reginhild, and 603 Timandra", The Minor Planet Bulletin 38 (2), pp. 76–78, Bibcode:2011MPBu...38...76P.

    External links

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