25 Phocaea

From Wikipedia, the free encyclopedia
Jump to: navigation, search
25 Phocaea
25Phocaea (Lightcurve Inversion).png
A three-dimensional model of 25 Phocaea based on its light curve.
Discovery
Discovered by J. Chacornac
Discovery date April 6, 1853
Designations
Pronunciation /fˈsə/ foh-SEE
Named after
Phōcæa
1956 GC
Minor planet category 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[2] kg
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, from whence came the founders of Marseille.

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[edit]

  1. ^ a b c d e "JPL Small-Body Database Browser: 25 Phocaea". Jet Propulsion Laboratory. 2011-12-30 last obs. Retrieved 2012-01-26. 
  2. ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: 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", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 38 (2): 76-78, Bibcode:2011MPBu...38...76P. 

External links[edit]