| Discovery[1] | |
|---|---|
| Discovered by | NEAT |
| Discovery site | Haleakala Obs. |
| Discovery date | 19 July 1998 |
| Designations | |
| (12538) 1998 OH | |
| 1998 OH | |
| NEO · Apollo · PHA[1][2] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 25.96 yr (9,483 days) |
| Aphelion | 2.1674AU |
| Perihelion | 0.9155 AU |
| 1.5414 AU | |
| Eccentricity | 0.4061 |
| 1.91yr (699 days) | |
| 58.305° | |
| 0° 30m 54s / day | |
| Inclination | 24.529° |
| 220.75° | |
| 321.72° | |
| Earth MOID | 0.0280 AU · 10.9LD |
| Physical characteristics | |
| Dimensions | 1.663±0.329 km[3][4] 2.06 km(calculated)[5] |
| 2.58±0.001h[6] 2.582±0.001 h[6] 5.088±0.004 h[7] 5.154 h[5] 5.191±0.002 h[8] 5.833±0.005 h[9] | |
| 0.20(assumed)[5] 0.232±0.116[3][4] | |
| SMASS =S:[1] · S[5] | |
| 15.8[1][5] · 16.1[4] | |
(12538) 1998 OH is a stonyasteroid, classified asnear-Earth object andpotentially hazardous asteroid of theApollo group, approximately 1.8 kilometers (1.1 mi) in diameter. It was discovered on 19 July 1998, by astronomers of theNear-Earth Asteroid Tracking program at theHaleakala Observatory in Hawaii, United States.[2] Thisminor planet wasnumbered by theMinor Planet Center on 23 November 1999.[10] As of 2018, it has not beennamed.[2] In 2019, the asteroid came within about 73lunar distances of Earth.
1998 OH is a member of theApollo group of asteroids, which areEarth-crossing asteroids. They are the largest group ofnear-Earth objects with approximately 10,000 known members.
It orbits the Sun at a distance of 0.9–2.2 AU in 1 year and 11 months (699 days). Its orbit has aneccentricity of 0.41 and aninclination of 25° with respect to theecliptic.[1] The body'sobservation arc begins with aprecovery taken atPalomar Observatory in October 1991, more than 7 years prior to its official discovery observation at Haleakala.[2]
The asteroid has an Earthminimum orbital intersection distance of 0.0280 AU (4.19 million km; 2.60 million mi), which corresponds to 10.9lunar distances and makes it apotentially hazardous asteroid due to its sufficiently large size.[1] It will pass close to Earth in 2042 and 2132, at distances of 0.0292 AU and 0.0317 AU, respectively.[1]
In theSMASS classification,1998 OH is a common stonyS-type asteroid.[1]
In 2014, several rotationallightcurves of1998 OH were obtained from photometric observations by American astronomerBrian Warner at the Palmer Divide Station in California, by the Spanish amateur astronomer group OBAS, and by astronomers of theEURONEAR lightcurve NEO survey. Lightcurve analysis gave arotation period of 5.154 hours with an alternative period solution of 2.58 hours, or half the period. The asteroid's brightness amplitude is rather low with a maximum between 0.11 and 0.20magnitude, which is indicative for a spherical rather than elongated shape (U=3/3/2-/3/2/2).[5][6][7][8][9][a][b]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,1998 OH measures 1.663 kilometers in diameter and its surface has analbedo of 0.232.[3][4] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 2.06 kilometers based on anabsolute magnitude of 15.8.[5]
