| Discovery[1] | |
|---|---|
| Discovered by | A. Kopff |
| Discovery site | Heidelberg Obs. |
| Discovery date | 3 March 1906 |
| Designations | |
| (589) Croatia | |
| Pronunciation | /kroʊˈeɪʃ(i)ə/[2] |
Named after | Croatia[3] (part ofAustria-Hungary) |
| 1906 TM · 1936 WM 1947 RA · 1953 RF1 1953 VR1 · 1953 VU A912 HH | |
| main-belt · (outer)[4] Croatia[5] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 111.34 yr (40,666d) |
| Aphelion | 3.2583AU |
| Perihelion | 3.0205 AU |
| 3.1394 AU | |
| Eccentricity | 0.0379 |
| 5.56yr (2,032 days) | |
| 161.92° | |
| 0° 10m 37.92s / day | |
| Inclination | 10.808° |
| 177.60° | |
| 223.88° | |
| Physical characteristics | |
| Dimensions | 84.44±22.49 km[6] 87.54±2.5 km[7] 87.66 km(derived)[4] 91.75±1.30 km[8] 93.617±1.015 km[9] 96.491±2.300 km[10] |
| 11.7±0.1h[11][a] 16.385±0.0931 h[12] 24.821±0.002 h[13] | |
| 0.041±0.006[14] 0.0419±0.0104[10] 0.047±0.002[8] 0.0509±0.003[7] 0.051±0.007[9] 0.0577(derived)[4] 0.06±0.06[6] | |
| Tholen =CX[1][4] · P[10] B–V = 0.73[1] U–B = 0.368[1] | |
| 8.938±0.004(R)[12] · 8.99±0.26[15] · 9.00[4][9] · 9.1[1] · 9.14[7][8][10] · 9.18[6] | |
589 Croatia, provisional designation1906 TM, is a darkasteroid and parent body of theCroatia family, located in the outer regions of theasteroid belt, approximately 88 kilometers in diameter. It was discovered in 1906, by astronomerAugust Kopff atHeidelberg Observatory, and later named for the independent country ofCroatia, then part ofAustria-Hungary.[3][16]
The asteroid was discovered on 3 March 1906, by German astronomerAugust Kopff at theHeidelberg-Königstuhl State Observatory in southwest Germany,[16] with the use of the photographic method. In the moment of the discovery, the asteroid was 12.5mv and was in the constellation of Virgo. The discovery was published in theAstronomische Nachrichten magazine, in the article wrote by Professor Wolf. Later, some astronomers (Johann Palisa,Karl Lohnert and some others) were making measurements for the purpose of determining theorbital elements. From these measurements P. V. Neugebauer from Berlin and M.S. Mello and Simas from Trafaria (Lisbon) had independently determined the first orbital elements. Observations had continued, and among observers there wereA. Kopff, E. Bianchi, A. Abetti, G. Zappa, P. Chafardet,E. Millosevich, J. Palisa, and some others. Observations were made from Berlin, Copenhagen, Rome, Arcetra and some other Italian cities.[17][18]
Croatia is theparent body of theCroatia family (638), a smallasteroid family of less than 100 known members.[5][19]: 23 It orbits the Sun in theouter main belt at a distance of 3.0–3.3 AU once every 5 years and 7 months (2,032 days;semi-major axis of 3.14 AU). Its orbit has aneccentricity of 0.04 and aninclination of 11° with respect to theecliptic.[1] The body'sobservation arc begins at Heidelberg, sixteen days after its official discovery observation.[16]
In theTholen classification,Croatia is ambiguous, closest to a carbonaceousC-type and somewhat similar to that of anX-type asteroid,[1][4] while theWide-field Infrared Survey Explorer (WISE) characterized it as a primitiveP-type asteroid.[10] Nesvorný determined the overallspectral type for theCroatia family to be that of an X-type.[19]: 23
In July 2013, the so-far best-rated rotationallightcurve ofCroatia was obtained by astronomers Romain Montaigut, Arnaud Leroy,Raoul Behrend,René Roy, Donn Starkey, Maurice Audejean, Roberto Crippa and Federico Manzini. Lightcurve analysis gave a longer-than averagerotation period of 24.821 hours with a brightness variation of 0.25magnitude (U=2+).[13] The result supersedes photometric observations byBrian Warner and by astronomers at thePalomar Transient Factory, which measured a shorter period of 11.7 and 16.385 hours with an amplitude of 0.16 and 0.32, respectively (U=2/2).[11][12][a]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA's WISE telescope,Croatia measures between 84.44 and 96.491 kilometers in diameter and its surface has analbedo between 0.041 and 0.06.[6][7][8][9][10][14]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0577 and a diameter of 87.66 kilometers based on anabsolute magnitude of 9.0.[4] The radius of (probably) 28.452 km (and, consequently, the superficial area of 2543.2 km2, and equatorial circumference of 89.385 km) were determined by use ofArgelander's Method.[18]
Thisminor planet was named for the country ofCroatia, then part ofAustria-Hungary, after the suggestion made by astronomerMax Wolf. It also honors the foundation of the Astronomical Observatory of the Croatian Natural Sciences Society (Zagreb Observatory) inZagreb.[3][17]
