| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 12 July 1923 |
| Designations | |
| (997) Priska | |
| Pronunciation | /ˈprɪskə/[2] |
Named after | A girl's name picked from a popular Germancalendar[3] |
| 1923 NR · 1959 WA 1967 RN | |
| main-belt · (middle)[4] Adeona[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 93.71 yr (34,229 days) |
| Aphelion | 3.1568AU |
| Perihelion | 2.1787 AU |
| 2.6677 AU | |
| Eccentricity | 0.1833 |
| 4.36yr (1,592 days) | |
| 206.91° | |
| 0° 13m 34.32s / day | |
| Inclination | 10.508° |
| 247.11° | |
| 51.494° | |
| Physical characteristics | |
| Dimensions | 16.71±0.31 km[6] 18.20±0.28 km[7] 18.59 km(derived)[4] 18.60±5.07 km[8] 18.70±1.6 km[9] 19.45±1.99 km[10] 20.274±0.123 km[11] 20.391±0.119 km[12] |
| 16.22±0.01h[13] | |
| 0.037±0.014[6] 0.04±0.02[10] 0.05±0.04[8] 0.0511(derived)[4] 0.054±0.009[11] 0.0572±0.0004[12] 0.0801±0.016[9] 0.088±0.003[7] | |
| SMASS =Ch[1] | |
| 12.00[7][9][12] · 12.31±0.29[14] · 12.40[8] · 12.5[1][4] · 12.51[10] · 13.07[6] | |
997 Priska, provisional designation1923 NR, is a carbonaceous Adeonianasteroid from the central regions of theasteroid belt, approximately 19 kilometers in diameter. It was discovered on 12 July 1923, by astronomerKarl Reinmuth at theHeidelberg-Königstuhl State Observatory in southwest Germany.[15] The asteroid's name is a common German female name, unrelated to the discoverer's contemporaries.[3]
Priska is a member of theAdeona family (505),[5] a largefamily of carbonaceous asteroids in thecentral main belt, named after145 Adeona.[16]: 23 It orbits the Sun at a distance of 2.2–3.2 AU once every 4 years and 4 months (1,592 days). Its orbit has aneccentricity of 0.18 and aninclination of 11° with respect to theecliptic.[1]
The body'sobservation arc begins with its official discovery observation at Heidelberg.[15]
In theSMASS classification,Priska is a Ch-subtype, a hydrated carbonaceousC-type asteroid.[1]
In August 2006, a rotationallightcurve ofPriska was obtained from photometric observations by Italian amateur astronomers Roberto Crippa and Federico Manzini. Lightcurve analysis gave arotation period of 16.22 hours with a brightness amplitude of 0.61magnitude (U=2).[13] A high brightness variation is typically indicative for an elongated rather than spherical shape.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Priska measures between 16.71 and 20.391 kilometers in diameter and its surface has analbedo between 0.037 and 0.088.[6][7][8][9][10][11][12]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0511 and a diameter of 18.59 kilometers based on anabsolute magnitude of 12.5.[4]
Thisminor planet was named after a girl's name picked from the German popularcalendarDer Lahrer hinkende Bote.(de)
As with913 Otila and1144 Oda, Reinmuth selected names from this calendar due to his many asteroid discoveries that he had trouble thinking of proper names. These names are not related to the discoverer's contemporaries. The author of theDictionary of Minor Planet Names learned about Reinmuth's source of inspiration from private communications with Dutch astronomerIngrid van Houten-Groeneveld, who worked as a young astronomer at Heidelberg.[3]
