_Kovacia.png) Modelled shape ofKovacia from itslightcurve | |
| Discovery[1] | |
|---|---|
| Discovered by | J. Palisa |
| Discovery site | Vienna Obs. |
| Discovery date | 25 February 1917 |
| Designations | |
| (867) Kovacia | |
Named after | Friedrich Kovacs (Austrian physician)[2] |
| A917 DH · 1942 XF 1958 WA · 1917 BS | |
| Orbital characteristics[3] | |
| Epoch 31 May 2020 (JD 2459000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 102.93yr (37,594 d) |
| Aphelion | 3.4574AU |
| Perihelion | 2.6751 AU |
| 3.0663 AU | |
| Eccentricity | 0.1276 |
| 5.37 yr (1,961 d) | |
| 113.77° | |
| 0° 11m 0.96s / day | |
| Inclination | 5.9738° |
| 46.820° | |
| 70.135° | |
| Physical characteristics | |
Meandensity | 1.4 g/cm3(est.)[10] |
| 8.6772±0.0001 h[11] | |
| 11.5[1][3] | |
867 Kovacia (prov. designation:A917 DHor1917 BS) is an elongated, darkasteroid and member of theHygiea family from the outer regions of theasteroid belt. It was discovered on 25 February 1917, by astronomerJohann Palisa at theVienna Observatory in Austria.[1] The carbonaceousC/B-type asteroid has arotation period of 8.7 hours and measures approximately 24 kilometers (15 miles) in diameter. It was named after Austrian physicianFriedrich Kovacs (1861–1931).[2]
According toZappalà's classification of dynamical families, and when applying the synthetichierarchical clustering method (HCM) byNesvorný,Kovacia is a member of theHygiea family (601), a very largefamily of carbonaceous outer-belt asteroids, named after10 Hygiea, which is the main belt'sfourth-largest asteroid.[4][5][14]: 23 However, it is a non-familybackground asteroid according to another HCM-analysis byMilani andKnežević (AstDys).[6]
It orbits the Sun in theouter asteroid belt at a distance of 2.7–3.5 AU once every 5 years and 4 months (1,961 days;semi-major axis of 3.07 AU). Its orbit has aneccentricity of 0.13 and aninclination of 6° with respect to theecliptic.[3] The body'sobservation arc begins atVienna Observatory on 1 March 1917, or four nights after its official discovery observation.[1]
Thisminor planet was named by Palisa afterFriedrich Kovacs (1861–1931), a Vienna physician andinternists, who successfully treated and restored the health of the discoverer's wife. The famed Viennese cardiologist also treatedGustav Mahler, who had a defective heart. Kovacs imposed a curtailment of all forms of vigorous exercise, a strict regimen of rest and even the usage of apedometer to measure the composer's physical effort. These restrictions depressed Mahler and ultimately lead to theSymphony No. 9, his last completed work.[15] Thenaming was also mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 85).[2]
In theSDSS-based taxonomy,Kovacia is a dark and common carbonaceousC-type asteroid,[12] while in aspectroscopic study of theHygiea family from 2001, this asteroid has been classified as a somewhat brighterB-type asteroid.[13] The study finds a significant number of objects of this family to belong to thisspectral type. Both C/B-types agree with the overall spectral type for the Hygiea family listed by Nesvorný (601).[14]: 23
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In February 2008, a rotationallightcurve ofKovacia was obtained fromphotometric observations by a collaboration of French and Italian amateur astronomers includingRené Roy,Silvano Casulli,François Colas,Arnaud Leroy, Federico Manzini,Christophe Demeautis and Jean-François Coliac. Lightcurve analysis gave a well-definedrotation period of8.6772±0.0001 hours with a high brightness variation of0.86±0.02magnitude, indicative of a non-spherical, elongated shape (U=3). The result supersedes a previous observation by Roberto Crippa and Federico Manzini at the Sozzago Astronomical Station (A12) from November 2006, that determined a lower limit of 6 hours (U=1+).[11] Due to observedmutual occultation and eclipsing events, the collaboration of astronomers strongly suspectKovacia to be abinary asteroid with asatellite orbiting it every31.9580±0.0005 days.[11] However, no follow-up observations have been published. As of March 2020[update], this asteroid is neither listed atJohnston's Archive nor has it any kind of binary status in theLightcurve Data Base.[16][17]
In 2016, a modeled lightcurve gave a concurring sidereal period of8.67807±0.00002 hours using data from the Uppsala Asteroid Photometric Catalogue, thePalomar Transient Factory survey, and individual observers (such as above), as well as sparse-in-time photometry from theNOFS, theCatalina Sky Survey, and the La Palma surveys (950). The study also determined twospin axes of (200.0°, −44.0°) and (38.0°, −50.0°) inecliptic coordinates (λ, β).[18]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer (WISE), and the JapaneseAkari satellite,Kovacia measures (24.04±2.2), (24.113±0.439) and (25.02±0.63) kilometers in diameter and its surface has analbedo of (0.0923±0.019), (0.092±0.023) and (0.088±0.005), respectively.[7][8][9] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0772 and a diameter of 23.96 kilometers based on anabsolute magnitude of 11.5.[16] Alternative mean-diameter measurements published by the WISE team include (19.808±4.804 km) and (21.049±8.124 km) with corresponding albedos of (0.096±0.067) and (0.093±0.063).[4][16]
