| Discovery[1] | |
|---|---|
| Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels |
| Discovery site | Palomar Obs. |
| Discovery date | 24 September 1960 |
| Designations | |
| (3201) Sijthoff | |
Named after | Albert Georg Sijthoff[1] (Dutch publisher) |
| 6560 P-L · 1969 FE 1979 DP | |
| main-belt[1][2] · (inner) background[3][4] · Flora[5] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 62.45yr (22,809 d) |
| Aphelion | 2.4553AU |
| Perihelion | 2.0605 AU |
| 2.2579 AU | |
| Eccentricity | 0.0874 |
| 3.39 yr (1,239 d) | |
| 179.37° | |
| 0° 17m 25.8s / day | |
| Inclination | 2.9903° |
| 109.47° | |
| 53.275° | |
| Physical characteristics | |
| 5.030±0.053 km[6] 5.205±0.042 km[7] 5.41 km(calculated)[5] | |
| 4.607±0.0016 h[8] | |
| 0.2164±0.0355[7] 0.231±0.047[6] 0.24(assumed)[5] | |
| S(assumed)[5] | |
| 13.5[2][5] 13.62±0.41[9] 13.7[7] 14.158±0.004(S)[8] | |
3201 Sijthoff, provisional designation6560 P-L, is a background or Florianasteroid from the inner regions of theasteroid belt, approximately 5 kilometers (3.1 miles) in diameter. It was discovered during thePalomar–Leiden survey on 24 September 1960, byIngrid andCornelis van Houten at Leiden, andTom Gehrels atPalomar Observatory in California, United States. The assumedS-type asteroid has arotation period of 4.607 hours. It was named after Dutch publisher and popularizer of astronomy,Albert Georg Sijthoff.[1][5]
Sijthoff is a non-family asteroid of the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements.[3][4] Based on osculating Keplerianorbital elements, the asteroid has also been classified as a member of theFlora family (402), a giantasteroid family and the largest family of stony asteroids in the main-belt.[5]
It orbits the Sun in theinner asteroid belt at a distance of 2.1–2.5 AU once every 3 years and 5 months (1,239 days;semi-major axis of 2.26 AU). Its orbit has aneccentricity of 0.09 and aninclination of 3° with respect to theecliptic.[2] The body'sobservation arc begins with aprecovery taken at Palomar in December 1954, nearly 6 years prior to its official discovery observation.[1]
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 ofseveral thousand asteroid discoveries.[10]
Sijthoff is an assumedS-type asteroid, according to its classification to the Flora family.[5]
In October 2011, a rotationallightcurve ofSijthoff was obtained fromphotometric observations in the S-band by astronomers at thePalomar Transient Factory in California. Lightcurve analysis gave arotation period of 4.607 hours with a brightness amplitude of 0.29magnitude (U=2).[5][8]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Sijthoff measures between 5.030 and 5.205 kilometers in diameter and its surface has analbedo between 0.2164 and 0.231.[6][7] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from8 Flora, the parent body of the Flora family – and calculates a diameter of 5.41 kilometers based on anabsolute magnitude of 13.5.[5]
Thisminor planet was named afterAlbert Georg Sijthoff, publisher of the independent newspaperHaagsche Courant, who promoted the popularization of astronomy in theNetherlands.[1] The Sijthoff family backed the 1934 construction of the "Sijthoff Planetarium" inthe Hague which burned down in 1975 and was replaced by theOmniversum.[11] The official naming citation was published by theMinor Planet Center on 5 November 1987 (M.P.C. 12458).[12]
