| Discovery[1] | |
|---|---|
| Discovered by | P. Wild |
| Discovery site | Zimmerwald Obs. |
| Discovery date | 6 February 1973 |
| Designations | |
| (2033) Basilea | |
Named after | Basel(Swiss city)[2] |
| 1973 CA · 1953 DA 1953 EY · 1955 WD 1955 XD | |
| main-belt · (inner)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63.33 yr (23,133 days) |
| Aphelion | 2.4734AU |
| Perihelion | 1.9765 AU |
| 2.2250 AU | |
| Eccentricity | 0.1117 |
| 3.32yr (1,212 days) | |
| 191.60° | |
| 0° 17m 49.2s / day | |
| Inclination | 8.4634° |
| 321.72° | |
| 14 November 2025[4] | |
| 134.56° | |
| Physical characteristics | |
| Dimensions | 5.710±0.088 km[5] 6.25±1.51 km[6] 6.322±0.051 km[7] 7.82 km(calculated)[3] |
| 6.5287±0.0002h[a] | |
| 0.20(assumed)[3] 0.29±0.13[6] 0.3688±0.0966[7] 0.419±0.088[5] | |
| S[3] | |
| 14.9[8] to 18.4 | |
| 12.7[7] · 12.9[1][3] · 13.01±0.09[9] · 13.19[6] | |
2033 Basilea, provisional designation1973 CA, is a stonyasteroid from the inner regions of theasteroid belt, approximately 6 kilometers in diameter. It was discovered on 6 February 1973, by astronomerPaul Wild at theZimmerwald Observatory near Bern, Switzerland.[10] The asteroid was named for the Swiss city ofBasel.[2] It came toperihelion in November 2025 andopposition on 23 January 2026 atapparent magnitude 15 in the constellation ofCancer.[11]
Basilea orbits the Sun in theinner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,212 days). Its orbit has aneccentricity of 0.11 and aninclination of 8° with respect to theecliptic.[1]
The asteroid was first identified as1953 DA atGoethe Link Observatory in February 1953, extending the body'sobservation arc by 20 years prior to its official discovery observation at Zimmerwakd.[10]
In December 2015, a rotationallightcurve ofBasilea was obtained from photometric observations by astronomersPetr Pravec,Peter Kušnirák andDonald Pray. Lightcurve analysis gave arotation period of 6.5287 hours with a brightness variation of 0.28magnitude (U=3-).[a]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Basilea measures between 5.710 and 6.322 kilometers in diameter and its surface has analbedo between 0.29 and 0.419.[5][6][7]
TheCollaborative Asteroid Lightcurve Link assumes a standard albedo forstony asteroids of 0.20 and calculates a diameter of 7.82 kilometers based on anabsolute magnitude of 12.9.[3]
Thisminor planet was named for the Swiss city ofBasel, as well as for theAstronomical Institute of the University of Basel on the occasion of its 50th anniversary.[2] The approved naming citation was published by theMinor Planet Center on 1 June 1980 (M.P.C. 5359).[12]
