| Discovery[1] | |
|---|---|
| Discovered by | C. J. van Houten I. van Houten-G. T. Gehrels |
| Discovery site | Palomar Obs. |
| Discovery date | 26 March 1971 |
| Designations | |
| (10252) Heidigraf | |
Named after | Heidi Graf[1] (ESA manager) |
| 4164 T-1 · 1978 VX15 | |
| main-belt[1][2] · (outer) Koronis[3][4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 46.83yr (17,106 d) |
| Aphelion | 3.0525AU |
| Perihelion | 2.6524 AU |
| 2.8524 AU | |
| Eccentricity | 0.0701 |
| 4.82 yr (1,760 d) | |
| 138.89° | |
| 0° 12m 16.56s / day | |
| Inclination | 2.2591° |
| 33.300° | |
| 289.53° | |
| Physical characteristics | |
| 5.15 km(calculated)[4] 5.782±0.203 km[5][6] | |
| 0.24(assumed)[4] 0.331±0.057[5] 0.4007±0.1010[6] | |
| S(assumed)[4] | |
| 12.8[6] 13.160±0.190(R)[7] 13.2[2] 13.61[4] | |
10252 Heidigraf, provisional designation4164 T-1, is a Koronianasteroid from the outer regions of theasteroid belt, approximately 6 kilometers (3.7 miles) in diameter. It was discovered during thePalomar–Leiden Trojan survey on 26 March 1971, byIngrid andCornelis van Houten at Leiden, andTom Gehrels atPalomar Observatory in California, United States. The likely elongatedS-type asteroid has a brightness variation of 0.56magnitude.[4] It was named afterHeidi Graf, a former Head of theESTEC Communications Office.[1]
Heidigraf is a core member of theKoronis family (605),[4][3] a very large outerasteroid family of six thousand known members with nearly co-planar ecliptical orbits.[8] It orbits the Sun in theouter main-belt at a distance of 2.7–3.1 AU once every 4 years and 10 months (1,760 days;semi-major axis of 2.85 AU). Its orbit has aneccentricity of 0.07 and aninclination of 2° with respect to theecliptic.[2] The body'sobservation arc begins at Palomar on 24 March 1971, two nights prior to its official discovery observation.[1]
Thesurvey designation "T-1" stands for the firstPalomar–Leiden Trojan survey, named after the fruitful collaboration of the Palomar andLeiden Observatory in the 1960s and 1970s. Gehrels used Palomar'sSamuel Oschin telescope (also known as the 48-inch Schmidt Telescope), and shipped thephotographic plates to Ingrid and Cornelis van Houten at Leiden Observatory whereastrometry was carried out. The trio are credited with the discovery ofseveral thousand asteroid discoveries.[9]
Heidigraf is an assumed stonyS-type asteroid,[4] which is the overallspectral type of the Koronis family.[8]: 23
In January 2014, astronomers at thePalomar Transient Factory observedHeidigrafphotometrically in the R-band during which it showed a brightness amplitude of 0.56magnitude, indicative for a non-spheroidal shape. However no rotationallightcurve could be constructed and itsrotation period remains unknown.[4][7]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Heidigraf measures 5.782 kilometers in diameter and its surface has analbedo of 0.331 and 0.4007, respectively.[5][6] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.24 and calculates a diameter of 5.15 kilometers based on anabsolute magnitude of 13.61.[4]
Thisminor planet was named afterHeidi Graf (born 1941), former Head of theEuropean Space Research and Technology Centre (ESTEC) Communications Office from 1977 to 2006 at theEuropean Space Agency, ESA.[1] The official naming citation was published by theMinor Planet Center on 9 November 2006 (M.P.C. 57950).[10]
