| Discovery [1] | |
|---|---|
| Discovered by | C. S. Shoemaker E. M. Shoemaker |
| Discovery site | Palomar Obs. |
| Discovery date | 25 September 1987 |
| Designations | |
| (4450) Pan | |
| Pronunciation | /ˈpæn/[2] |
Named after | Pan(Greek deity)[3] |
| 1987 SY · 1937 CA | |
| NEO · Apollo · PHA [1][4] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 78.85 yr (28,799 days) |
| Earliestprecovery date | 6 February 1937 |
| Aphelion | 2.2884AU |
| Perihelion | 0.5962 AU |
| 1.4423 AU | |
| Eccentricity | 0.5866 |
| 1.73yr (633 days) | |
| 152.71° | |
| 0° 34m 8.4s / day | |
| Inclination | 5.5196° |
| 311.84° | |
| 291.79° | |
| Earth MOID | 0.0287 AU · 11.2LD |
| Physical characteristics | |
| 1.0±0.2 km[5] 1.13 km(calculated)[6] | |
| 3.51±0.02h[7] 56.48±0.02 h[8] 60±12 h[a] | |
| 0.20(assumed)[6] | |
| S [6] | |
| 17.1[1][6] · 17.43±0.07[5] | |
4450 Pan (prov. designation:1987 SY) is a highly eccentricasteroid andcontact binary, classified as apotentially hazardous asteroid andnear-Earth object of theApollo group, approximately 1.1 kilometers in diameter. It was discovered on 25 September 1987, by American astronomersEugene andCarolyn Shoemaker atPalomar Observatory in California, United States.[4] It was named afterPan from Greek mythology.[3]
Thisminor planet was named afterPan, the Greek god of nature, shepherds of flocks and wild animals.[3] In art, he was represented as a horned half-man, half goat. Pan was worshiped by the citizens of Athens, after he had inspired panic in the hearts of their Persians enemies in theBattle of Marathon(also see4356 Marathon). The modern word "panic" origins from this myth. The namePan has also been given toSaturn XVIII, one of themoons of Saturn.[3] The official naming citation was published by theMinor Planet Center on 30 January 1991 (M.P.C. 17657).[9]
Pan orbits the Sun in theinner main-belt at a distance of 0.6–2.3 AU once every 1 years and 9 months (633 days). Its orbit has aneccentricity of 0.59 and aninclination of 6° with respect to theecliptic.[1]
As an Apollo asteroid, it is anEarth-crosser and has aminimum orbit intersection distance with Earth of 0.0287 AU (4,290,000 km), which corresponds to 11.2lunar distances. Due to its extremely eccentric orbit, it is also aVenus- andMars-crosser and approaches Mercury within 20 Gm.
It was first observed as1937 CA atHeidelberg Observatory in 1937. The body'sobservation arc begins at Palomar with its official discovery observation.[4]
Pan is an assumed stonyS-type asteroid.[6]
Pan is acontact binary, composed of two lobes in mutual contact, held together only by their weak gravitational attraction, and typically show a dumbbell-like shape(also see4769 Castalia).[10] A large number ofnear-Earth objects are thought to be contact binaries.[11]
TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 1.1 kilometers,[6] while photometric observations by ItalianAlbino Carbognani at Saint-Barthelemy Observatory (B04) gave a diameter of1.0±0.2 kilometers.[5]
In September 2013, a rotationallightcurve ofPan was obtained from photometric observations by American astronomerBrian Warner at his Palmer Divide Station (716) in Colorado. It gave a longrotation period of56.48±0.02 hours with a brightness variation of 0.64 inmagnitude (U=3).[8]
The results supersedes two previous observations byPetr Pravec atSilvano Casulli that gave a period of60±12 and3.51±0.02 hours, respectively (U=2/1).[a][7]
