5011 Ptah

5011 Ptah

Discovery
Discovered by	C. van Houten I. van Houten T. Gehrels
Discovery site	Palomar Obs.
Discovery date	24 September 1960
Designations
MPC designation	5011 Ptah
Named after	Ptah (Egyptian mythology)
Alternative names	6743 P–L · 1983 TF2
Minor planet category	Apollo · NEO · PHA Mars-crosser
Orbital characteristics
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc	53.94 yr (19,701 days)
Aphelion	2.4535 AU
Perihelion	0.8177 AU
Semi-major axis	1.6356 AU
Eccentricity	0.5000
Orbital period	2.09 yr (764 days)
Mean anomaly	12.097°
Inclination	7.4075°
Longitude of ascending node	10.783°
Argument of perihelion	105.74°
Earth MOID	0.0249 AU
Physical characteristics
Dimensions	1.56 km (calculated)
Geometric albedo	0.20 (assumed)
Spectral type	Q
Absolute magnitude (H)	16.4

5011 Ptah, provisional designation 6743 P–L, is a rare-type, highly eccentric asteroid, classified as potentially hazardous object and Apollo asteroid, about 1.6 kilometers in diameter. It was discovered on 24 September 1960, by Dutch astronomers Ingrid and Cornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomer Tom Gehrels at Palomar.

The rare Q-type asteroid orbits the Sun at a distance of 0.8–2.5 AU once every 2 years and 1 month (764 days). Its orbit is tilted by 7 degrees to the plane of the ecliptic and shows an exceptionally high eccentricity of 0.50. The Collaborative Asteroid Lightcurve Link (CALL) assumes an albedo of 0.20. As a potentially hazardous asteroid, it has a short Earth minimum orbit intersection distance (MOID) of 0.025 AU. It passes within that distance of Earth 15 times between 1900 and 2100, most recently on 21 January 2007, at 29.6 Gm. The next time will be in 2027 at 28.6 Gm. In addition, the asteroid crosses the orbit of Mars and classifies as a Mars-crosser.

The designation P–L stands for Palomar–Leiden, named after Palomar Observatory and Leiden Observatory, which collaborated on the fruitful Palomar–Leiden survey in the 1960s. Gehrels used Palomar's Samuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped the photographic plates to Cornelis and Ingrid van Houten at Leiden Observatory, where astrometry was carried out. The trio are credited with several thousand asteroid discoveries.

The minor planet was named for Ptah, the creator of the universe and a patron of craftsmen, especially sculptors, in Egyptian mythology. Ptah was originally the local deity of Memphis, capital of Egypt from the 1st dynasty; the political importance of Memphis led to the expansion of Ptah's cult throughout Egypt. The deity was always represented in purely human form, often swathed in a winding sheet. On the same night Ptah was discovered, the trio of astronomers also discovered the minor planets 1912 Anubis, 1923 Osiris and 1924 Horus, which are also named after Ancient Egyptian deities.

External links

• Asteroid Lightcurve Database (LCDB), query form (info)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
• 5011 Ptah at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters