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]}

Orbit and classification

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]

Naming

This minor planet was named after Diane Callahan, teacher at U.S. Fairfield Middle School, Ohio, who mentored a finalist in the 2003 Discovery Channel Youth Science Challenge ( DCYSC), a middle school science competition. ^[2] The approved naming citation was published by the Minor Planet Center on 10 October 2003 ( M.P.C. 49772). ^[8]

References

External links

• Asteroid Lightcurve Database (LCDB), query form ( info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (15001)-(20000) – Minor Planet Center
• 19741 Callahan at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 19741 Callahan at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters