| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 18 March 1936 |
| Designations | |
| (1421) Esperanto | |
Named after | Esperanto[1] (artificial language) |
| 1936 FQ · 1931 HC 1958 GD · A906 UD A917 XD · A920 GD | |
| main-belt[1][2] · (outer) background[3][4] | |
| Orbital characteristics[2] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 111.92yr (40,879 d) |
| Aphelion | 3.3505AU |
| Perihelion | 2.8280 AU |
| 3.0893 AU | |
| Eccentricity | 0.0846 |
| 5.43 yr (1,983 d) | |
| 77.705° | |
| 0° 10m 53.4s / day | |
| Inclination | 9.8030° |
| 42.595° | |
| 163.18° | |
| Physical characteristics | |
| 43.31±3.1 km[5] 51.95±10.21 km[6][7] 56.68±0.96 km[8] 62.06±17.35 km[9] 64.37±25.60 km[10] | |
| 21.982±0.005 h[11] | |
| 0.03[9][10] 0.042[8] 0.0714±0.011[5] 0.098[6][7] | |
| C(assumed)[12] | |
| 9.56[7] 10.30[6][8][9] 10.4[1][2] 10.42[10] | |
1421 Esperanto, provisional designation1936 FQ, is a dark backgroundasteroid from the outer regions of theasteroid belt, approximately 55 kilometers (34 miles) in diameter. It was discovered on 18 March 1936, by Finnish astronomerYrjö Väisälä at theIso-Heikkilä Observatory in Turku, southwest Finland. The presumedC-type asteroid has arotation period of nearly 22 hours.[12] It was named for the artificial languageEsperanto.[1]
Esperanto has been determined a non-family asteroid from the main belt'sbackground population by means of modernHCM-analysis, after it had previously been grouped to theEos family byZappalà in the 1990s.[3][4]
It orbits the Sun in theouter asteroid belt at a distance of 2.8–3.4 AU once every 5 years and 5 months (1,983 days;semi-major axis of 3.09 AU). Its orbit has aneccentricity of 0.08 and aninclination of 10° with respect to theecliptic.[2] The body'sobservation arc begins with its first observation as1906 UD atHeidelberg Observatory in October 1906, almost 30 years prior to its official discovery observation at Turku.[1]
Thisminor planet was named by the discoverer after theconstructed language,Esperanto, which was created by inventor and writer,Ludwik Lejzer Zamenhof (1859–1917), who used the pseudonym "Doktoro Esperanto".[1] The discoverer also named another asteroid,1462 Zamenhof, directly after the inventor. Both asteroids are considered to be the most remoteZamenhof-Esperanto objects. The officialnaming citation was published by theMinor Planet Center in January 1956 (M.P.C. 1350).[13]
Esperanto is an assumed, carbonaceousC-type asteroid.[12]
In March 2012, a rotationallightcurve ofEsperanto was obtained fromphotometric observations by Andrea Ferrero at the Bigmuskie Observatory (B88) in northern Italy. Lightcurve analysis gave arotation period of21.982±0.005 hours with a brightness amplitude of 0.15magnitude (U=3-).[11]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Esperanto measures between 43.3 and 64.3 kilometers in diameter and its surface has analbedo between 0.03 and 0.098.[5][6][7][8][9][10]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0714 and a diameter of 43.31 kilometers based on anabsolute magnitude of 10.3.[12][5]
