19741 Callahan
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| Discovery[1] | |
|---|---|
| Discovered by | LINEAR |
| Discovery site | Lincoln Lab ETS |
| Discovery date | 5 January 2000 |
| Designations | |
| (19741) Callahan | |
Named after | Diane Callahan (mentor at DCYSC)[2] |
| 2000 AN141 · 1978 RQ8 | |
| main-belt[3] · (inner)[4] background | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 38.66 yr (14,121 days) |
| Aphelion | 2.5407 AU |
| Perihelion | 1.9559 AU |
| 2.2483 AU | |
| Eccentricity | 0.1301 |
| 3.37 yr (1,231 days) | |
| 163.76° | |
| 0° 17m 32.64s / day | |
| Inclination | 8.0506° |
| 167.39° | |
| 227.28° | |
| Physical characteristics | |
| Dimensions | 3.12 km (calculated)[4] 3.876±0.166 km[5][6] |
| 7.2684±0.0015 h[7] | |
| 0.20 (assumed)[4] 0.224±0.044[5][6] | |
| S[4] | |
| 14.3[5] · 14.4[1] · 14.444±0.004[7] · 14.89[4] | |
19741 Callahan (provisional designation 2000 AN141) is a stony background asteroid from the inner regions of the asteroid belt, approximately 3.5 kilometers in diameter.
It was discovered on 5 January 2000, by the Lincoln Near-Earth Asteroid Research, LINEAR, at the Lincoln Laboratory's Experimental Test Site, Socorro, New Mexico, and named after a mentor of the 2003 Discovery Channel Young Scientist Challenge.[2][3]
The S-type asteroid orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,231 days). Its orbit has an eccentricity of 0.13 and an inclination of 8° with respect to the ecliptic.[1] Callahan was first identified as 1978 RQ8 at ESO's La Silla Observatory in 1978, which extends the asteroid's observation arc by 22 years prior to its official discovery observation.[3]
Physical characteristics
In December 2009, a rotational lightcurve for this asteroid was obtained from photometric observations at the U.S. Palomar Transient Factory, California. It gave a rotation period of 7.2684±0.0015 hours with a relatively high brightness variation of 0.81 in magnitude (U=2), indicative of a non-spherical shape.[7]
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Callahan measures 3.9 kilometers in diameter and its surface has an albedo of 0.22.[5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 3.1 kilometers, with an absolute magnitude of 14.89.[4]
