147 Protogeneia
| Discovery and designation | |
|---|---|
| Discovered by | Lipót Schulhof |
| Discovery date | July 10, 1875 |
| Designations | |
| Named after | Protogeneia |
| Minor planet category | Main belt |
| Orbital characteristics | |
| Epoch December 31, 2006 (JD 2454100.5) | |
| Aphelion | 484.856 Gm (3.241 AU) |
| Perihelion | 452.926 Gm (3.028 AU) |
| Semi-major axis | 468.891 Gm (3.134 AU) |
| Eccentricity | 0.034 |
| Orbital period | 2026.831 d (5.55 a) |
| Average orbital speed | 16.82 km/s |
| Mean anomaly | 185.625° |
| Inclination | 1.935° |
| Longitude of ascending node | 248.729° |
| Argument of perihelion | 106.744° |
| Physical characteristics | |
| Dimensions |
132.93 km[1] 118.44 ± 10.45[2] km |
| Mass | (1.23 ± 0.05) × 1019[2] kg |
| Mean density | 14.13 ± 3.78[2] g/cm3 |
| Equatorial surface gravity | 0.0371 m/s² |
| Equatorial escape velocity | 0.0703 km/s |
| Rotation period | 7.8528[3] h |
| Geometric albedo | 0.0492[1] |
| Temperature | ~157 K |
| Spectral type | C |
| Apparent magnitude | 12.4 to 14.5 |
| Absolute magnitude (H) | 8.27[3] |
|
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147 Protogeneia is a large main belt asteroid that was discovered by the Hungarian astronomer Lipót Schulhof on July 10, 1875 from the Vienna Observatory; it was his only asteroid discovery. Its name is Greek for "first born" and was chosen by Karl L. Littrow in allusion to the fact that this was the first asteroid discovered by an astronomer who was already known for work in other fields of astronomy.[4]
This object has a low orbital eccentricity and inclination. With an orbital period roughly double that of the planet Jupiter, it has been identified as a member of the Hecuba group of asteroids that share a 2:1 mean-motion orbital resonance with the giant planet.[5] Based upon its spectrum, it has a Tholen classification as a C-type asteroid,[6] which indicates has a dark surface and probably a primitive composition of carbonaceous material.
Photometric observations of this asteroid at the Altimira Observatory in 2004 gave a light curve with a period of 7.8528 ± 0.0008 hours and a brightness variation of 0.28 in magnitude.[3] A photometric study was reported in 2006 from the Yunnan Observatory in China, finding a matching period of 7.852 hours and a brightness variation of 0.25 magnitude. They estimate the ratio of the lengths for the asteroid's major and minor axes is at least 1.26:1.[7]
There is one reported stellar occultation by Protogeneia, on May 28, 2002, from Texas.[citation needed]
References
- ↑ 1.0 1.1 Yeomans, Donald K., "147 Protogeneia", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-05-02.
- ↑ 2.0 2.1 2.2 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.
- ↑ 3.0 3.1 3.2 Buchheim, Robert K. (June 2005), "Lightcurve of 147 Protogeneia", The Minor Planet Bulletin (ISSN 1052-8091). Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 32 (2): 35–36, Bibcode:2005MPBu...32...35B.
- ↑ Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names (5th ed.), Springer, p. 28, ISBN 3540002383.
- ↑ Levy, Sophia H. (August 1939), "Mean Elements and Perturbations by the Berkeley Tables of Minor Planets of the Hecuba Group", Publications of the Astronomical Society of the Pacific 51 (302): 225, Bibcode:1939PASP...51..224L, doi:10.1086/125066.
- ↑ Bel'Skaya, I. N. et al. (1991), "Polarimetry of CMEU asteroids. II. A peculiarity of M-type asteroids", Kinematics and Physics of Celestial Bodies 7 (6): 8–11, Bibcode:1991KPCB....7....8B.
- ↑ Zhang, Xi-Liang et al. (December 2006), "CCD Photometry of Asteroid (147) Protogeneia", Chinese Journal of Astronomy & Astrophysics 6 (6): 729–732, Bibcode:2006ChJAA...6..729Z, doi:10.1088/1009-9271/6/6/12.
External links
- Orbital simulation from JPL (Java)
- Horizons Ephemeris
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