_Piazzia.png) Modelled shape ofPiazzia from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | K. Reinmuth |
| Discovery site | Heidelberg Obs. |
| Discovery date | 12 August 1923 |
| Designations | |
| (1000) Piazzia | |
| Pronunciation | /piˈætsiə/[2] |
Named after | Giuseppe Piazzi[3] (Italian astronomer) |
| 1923 NZ · A923 PF 1951 OB · 1967 ED | |
| Orbital characteristics[4] | |
| Epoch 27 April 2019 (JD 2458600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 94.83yr (34,637 d) |
| Aphelion | 3.9909AU |
| Perihelion | 2.3511 AU |
| 3.1710 AU | |
| Eccentricity | 0.2586 |
| 5.65 yr (2,063 d) | |
| 347.91° | |
| 0° 10m 28.2s / day | |
| Inclination | 20.574° |
| 323.74° | |
| 280.90° | |
| Physical characteristics | |
| 9.47±0.01 h[12] | |
| C/Cb(S3OS2)[13] | |
| 9.60[8][11] 10.5[1][4][5] 10.60[14][9] 10.61[10] | |
1000 Piazzia, provisional designation1923 NZ, is a carbonaceous backgroundasteroid from the outer region of theasteroid belt, approximately 48 kilometers (30 miles) in diameter. It was discovered on 12 August 1923, by German astronomerKarl Reinmuth atHeidelberg Observatory in southern Germany. TheC-type asteroid has arotation period of 9.5 hours.[5] It was named after ItalianGiuseppe Piazzi, who discovered1 Ceres.[3]
Piazzia is a non-family asteroid from the main belt'sbackground population.[7] It orbits the Sun in theouter asteroid belt at a distance of 2.4–4.0 AU once every 5 years and 8 months (2,063 days;semi-major axis of 3.17 AU). Its orbit has aneccentricity of 0.26 and aninclination of 21° with respect to theecliptic.[4] As noprecoveries were taken, the body'sobservation arc begins with its first recorded observation on the night following its official discovery date.[1]
Thisminor planet was named in honour of ItalianTheatine monkGiuseppe Piazzi (1746–1826). He was a director of both thePalermo andNaples observatories, and known for the compilation of the Palermo Catalogue, containing the precise position of 7,646 stars. In 1801, Piazzi discovered1 Ceres, the first and largest asteroid and the main-belt's onlydwarf planet. He is also honored by the lunar craterPiazzi. The official naming citation was first mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 96).[3] The asteroid is the first of several early "kilo-numbered" minor planets that were dedicated to renowned scientists or institutions including:[15]
These are followed by the asteroids5000 IAU (for theInternational Astronomical Union),6000 United Nations (for theUnited Nations),7000 Curie (for the pioneers on radioactivity,Marie andPierre Curie), and8000 Isaac Newton (forIsaac Newton),[15] while9000 Hal (afterHAL 9000 from the movie2001: A Space Odyssey) and10000 Myriostos (after the Greek word for ten-thousandth, and to honor all astronomers) were named based on their direct numeric accordance.
1000 Piazzia was named as part of trio honoring the events surrounding the discovery of Ceres in 1801.[16] A person namedCarl Friedrich Gauss who computed the orbit of Ceres, andHeinrich Wilhelm Matthias Olbers who found it again later that year after it has passed behind the Sun.[16] In honor of them,1001 Gaussia for Gauss and1002 Olbersia for Olbers were named along with 1000 Piazzia.[16] In the next few years only three more astronomical bodies were found between Mars and Jupiter,Pallas,Juno, and4 Vesta, however it would be 37 years before another asteroid was found,5 Astraea in 1845.[16]
By 1868, 100 asteroids had been discovered, however it would not be until 1921 that the 1000th was discovered. The rate accelerated in the 20th century and the ten thousandth would be discovered in 1989.
In the Tholen- and SMASS-like taxonomy of theSmall Solar System Objects Spectroscopic Survey (S3OS2),Piazzia is a carbonaceousC-type and Cb-subtype, respectively, latter which transitions to the somewhat "brighter"B-type asteroids.[6][13]
AfterPiazzia had been published byThe Minor Planet Bulletin as an opportunity forphotometry in 2001, a classically shaped bimodallightcurve was obtained byRobert Stephens at the Santana Observatory (646) in Rancho Cucamonga, California. The lightcurve gave arotation period of9.47±0.01 hours with a brightness variation of 0.45magnitude (U=3).[12] A second lightcurve was obtained by astronomerRené Roy in March 2007, rendering a period of9.2±0.2 hours and an amplitude of 0.2 magnitude (U=2).[17]
TheCollaborative Asteroid Lightcurve Link derives a lowalbedo of 0.05 and a diameter of 47.19 kilometers based on anabsolute magnitude of 10.5.[5] According to the space-basedsurveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Piazzia measures between 45.72 and 51.55 kilometers in diameter and its surface has an albedo between 0.041 and 0.1119.[14][8][10][9][11]
