| Discovery[1] | |
|---|---|
| Discovered by | Spacewatch |
| Discovery site | Kitt Peak National Obs. |
| Discovery date | 21 April 1998 |
| Designations | |
| (20325) Julianoey | |
Named after | Julian Oey[2] (Australian photometrist) |
| 1998 HO27 · 1977 TT6 2004 BB159 | |
| main-belt · Vestian[3] background[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 63.43 yr (23,169 days) |
| Aphelion | 2.5620AU |
| Perihelion | 2.1956 AU |
| 2.3788 AU | |
| Eccentricity | 0.0770 |
| 3.67yr (1,340 days) | |
| 338.89° | |
| 0° 16m 6.96s / day | |
| Inclination | 6.1000° |
| 98.173° | |
| 257.30° | |
| Knownsatellites | 1(D: 1.42 km;P:23.54 h)[5] |
| Physical characteristics | |
| Dimensions | 4.73(derived)[5] 4.942±0.216 km[6] 6.81 km(calculated)[3] |
| 3.24474±0.0008h[7] | |
| 0.20(assumed)[3] 0.416±0.044[6] | |
| S(assumed)[3] | |
| 13.10[6] · 13.2[1][3] · 13.29±0.39[8] | |
20325 Julianoey (provisional designation1998 HO27) is a Vestianasteroid and a synchronousbinary system from the inner regions of theasteroid belt, approximately 5 kilometers (3 miles) in diameter. It was discovered on 21 April 1998, by astronomers of theSpacewatch survey atKitt Peak National Observatory near Tucson, Arizona. The asteroid was named after Australian photometristJulian Oey.[2] The discovery of itsminor-planet moon was announced in December 2014.[5][7]
Julianoey is a member of theVesta family (401), the second largest family in the asteroid belt, named after4 Vesta.[3] However, it is a non-family asteroid of the main belt'sbackground population when applying theHierarchical Clustering Method to itsproper orbital elements.[4]
It orbits the Sun in theinner asteroid belt at a distance of 2.2–2.6 AU once every 3 years and 8 months (1,340 days;semi-major axis of 2.38 AU). Its orbit has aneccentricity of 0.08 and aninclination of 6° with respect to theecliptic.[1] The body'sobservation arc begins with aprecovery taken atPalomar Observatory in May 1954, almost 44 years prior to its official discovery observation at Kitt Peak.[2]
Julianoey is an assumed stonyS-type asteroid.[3]
In December 2014, a rotationallightcurve of Julianoey was obtained from photometric observations byDonald Pray and several other astronomers across the world. Lightcurve analysis gave a well-definedrotation period of 3.24474 hours with a brightness amplitude of 0.13magnitude (U=3).[7]
The photometric observations from December 2014 also revealed that Julianoey is a synchronousbinary asteroid with aminor-planet moon orbiting it every 23.54 hours.[7] The satellite measures approximately 1.42 kilometers in diameter and its orbit has an estimated semi-major axis of 10 kilometers. The discovery was announced on 24 December 2014.[5]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer, Julianoey measures 4.942 kilometers in diameter and its surface has a highalbedo of 0.416.[6] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and consequently calculates a larger diameter of 6.81 kilometers based on anabsolute magnitude of 13.2.[3]
Thisminor planet was numbered on 9 January 2001 (M.P.C. 41904).[9] It was named afterJulian Oey (born 1964), a well-known asteroid photometrist, observing from Australia. He was the principal investigator that led to the discovery of four binary asteroids:2691 Sersic,3868 Mendoza,10208 Germanicus and15268 Wendelinefroger.[10]
As of 2017, he is also credited as co-discoverer of the following binary asteroids:1338 Duponta,1798 Watts,2121 Sevastopol,2343 Siding Spring,2478 Tokai,4541 Mizuno,5112 Kusaji,5481 Kiuchi,6186 Zenon,8306 Shoko,8474 Rettig,12326 Shirasaki,(15700) 1987 QD,(32039) 2000 JO23,(99913) 1997 CZ5 and(357439) 2004 BL86.[10]
The naming was suggested by astronomers Alan Harris andPetr Pravec. The official naming citation was published by theMinor Planet Center on 5 June 2016 (M.P.C. 100606; listed on 20 June 2016).[9]
