| Discovery[1] | |
|---|---|
| Discovered by | C. van Houten I. van Houten T. Gehrels |
| Discovery site | Palomar Obs. |
| Discovery date | 24 September 1960 |
| Designations | |
| (5011) Ptah | |
| Pronunciation | /ˈtɑː/[2] |
Named after | Ptah (Egyptian mythology)[3] |
| 6743 P-L · 1983 TF2 | |
| Apollo · NEO · PHA[1][4] Mars-crosser | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 55.90 yr (20,419 days) |
| Aphelion | 2.4533AU |
| Perihelion | 0.8181 AU |
| 1.6357 AU | |
| Eccentricity | 0.4998 |
| 2.09yr (764 days) | |
| 29.031° | |
| 0° 28m 15.96s / day | |
| Inclination | 7.4075° |
| 10.780° | |
| 105.75° | |
| Earth MOID | 0.0256 AU · 10LD |
| Physical characteristics | |
| 1.56 km(calculated)[5] | |
| 0.20(assumed)[5] | |
| Q[5][6] | |
| 16.4[1][5] | |
5011 Ptah (/ˈtɑː/;prov. designation:6743 P-L) is anear-Earth object andpotentially hazardous asteroid of theApollo group. It was discovered by astronomers with thePalomar–Leiden survey on 24 September 1960. The rareO-type asteroid on an eccentric orbit measures approximately 1.6 kilometers (1 mile) in diameter. It was named after the Ancient Egyptian deityPtah.
Ptah was discovered on 24 September 1960, by Dutch astronomersIngrid andCornelis van Houten at Leiden, on photographic plates taken by Dutch–American astronomerTom Gehrels at thePalomar Observatory in California.[4] On the same night, the trio of astronomers also discovered the minor planets1912 Anubis,1923 Osiris and1924 Horus, which were also named afterAncient Egyptian deities.
Thesurvey designation "P-L" stands forPalomar–Leiden, named after Palomar Observatory andLeiden Observatory, which collaborated on the fruitfulPalomar–Leiden survey in the 1960s. Gehrels used Palomar'sSamuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped thephotographic plates to Ingrid and Cornelis van Houten at Leiden Observatory whereastrometry was carried out. The trio are credited with the discovery of several thousand minor planets.[7]
Thisminor planet was named for the Egyptian creator deityPtah. InEgyptian mythology, he is the creator of the universe and god of craftsmen and architects. The deity was generally represented in a human form with asceptre and anankh.[3] The approved naming citation was published by theMinor Planet Center on 16 May 1992 (M.P.C.20163).[8]
Ptah orbits the Sun at a distance of 0.8–2.5 AU once every 2 years and 1 month (764 days). Its orbit has aneccentricity of 0.50 and aninclination of 7° with respect to theecliptic.[1] As noprecoveries were taken, the asteroid'sobservation arc begins with its official discovery observation at Palomar.[4]
Thepotentially hazardous asteroid has aminimum orbit intersection distance with Earth of 0.0256 AU (3,830,000 km) or 10lunar distances. 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.[1] Due to its high eccentricity,Ptah is also aMars-crosser.
According to the "ExploreNEOs" Warm Spitzer program,Ptah is a rareQ-type asteroid, that belongs to the broaderS-group of asteroids.[6]
TheCollaborative Asteroid Lightcurve Link assumes a standardalbedo for stony asteroids of 0.20, and calculates amean diameter of 1.6 kilometers using anabsolute magnitude of 16.4. As of 2017, no rotationallightcurves have been obtained ofPtah, and itsrotation period and shape, as well as itsspectral type remains unknown.[1][5]
