_Nancita.png) Shape model ofNancita from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | E. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 13 March 1988 |
| Designations | |
| (4222) Nancita | |
Named after | Nancy Coker Helin (discoverer's family)[2] |
| 1988 EK1 · 1950 TF4 1952 HN · 1968 QL1 1972 XQ1 · 1979 SL6 1983 XC1 · 1988 KL | |
| Mars-crosser exmain-belt · (inner) | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 48.77 yr (17,813 days) |
| Aphelion | 3.0666AU |
| Perihelion | 1.6705 AU |
| 2.3685 AU | |
| Eccentricity | 0.2947 |
| 3.65yr (1,331 days) | |
| 104.75° | |
| 0° 16m 13.44s / day | |
| Inclination | 3.7412° |
| 206.85° | |
| 217.61° | |
| Mars MOID | 0.1710 AU |
| Physical characteristics | |
| 8.47±0.8 km(IRAS:11)[3] 9.14±0.71 km[4] 9.636±0.121[5] 9.707±0.215 km[6] | |
| 3.8732±0.0003 h[7] | |
| 0.2057±0.0073[6] 0.209±0.013[5] 0.232±0.038[4] 0.2703±0.061(IRAS:11)[3] | |
| SMASS =S[1][8] | |
| 12.3[1] · 12.4[8][3][4][6] | |
4222 Nancita (prov. designation:1988 EK1) is a brightbackground asteroid and upcomingMars-crosser on an eccentric orbit from the inner regions of theasteroid belt. It was discovered on 13 March 1988, by American astronomerEleanor Helin atPalomar Observatory in California, United States.[9] TheS-type asteroid has arotation period of 3.9 hours and measures approximately 9 kilometers (5.6 miles) in diameter. It was named after the discoverer's daughter-in-law, Nancy Coker Helin.
Nancita is a non-family asteroid from the main belt'sbackground population when applying thehierarchical clustering method to itsproper orbital elements. It will become aMars-crossing asteroid in June 2019. It orbits the Sun in theinner main-belt at a distance of 1.7–3.1 AU once every 3 years and 8 months (1,331 days). Its orbit has aneccentricity of 0.29 and aninclination of 4° with respect to theecliptic.[1] The asteroid was first observed as1950 TF4 atMcDonald Observatory in 1950. Itsobservation arc begins atCrimea–Nauchnij in 1968, when it observed as1968 QL1, or 20 years prior to its official discovery observation at Palomar.[9]
Thisminor planet was named in honor of Nancy Coker Helin, daughter-in-law of the discoverer, and wife to Bruce Helin, after whom the minor planet2430 Bruce Helin had previously been named. Nancy is described by the discoverer as a talented singer, composer and teacher, who has brought music and joy to her family.[2] Theofficial naming citation was published by theMinor Planet Center on 2 December 1990 (M.P.C. 17466).[10]
In theSMASS classification,Nancita is a commonS-type asteroid.[1]
A rotationallightcurve ofNancita, obtained fromphotometric observations at the Australian Hunters Hill Observatory (E14) and collaborating stations in 2006, gave a well-definedrotation period of 3.8732 hours with a high brightness amplitude of 0.97 inmagnitude (U=3), indicating that the body has a non-spheroidal shape.[7]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Nancita measures between 8.5 and 9.7 kilometers in diameter and its surface has analbedo in the range of 0.21 to 0.27.[3][4][5][6] TheCollaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS.[8]
