Discovered by E. F. Helin MPC designation 8026 Johnmckay Minor planet category main-belt · Hungaria Discovered 8 May 1991 Orbits Sun Discovery site Palomar Observatory | Discovery date 8 May 1991 Alternative names 1991 JA1 · 1989 UF2 Observation arc 25.81 yr (9,427 days) Aphelion 2.07 m Discoverer Eleanor F. Helin | |
Named after John B. McKay (Test pilot) Similar 4015 Wilson–Harrington, Sun, 6489 Golevka, 9969 Braille, 4769 Castalia | ||
8026 Johnmckay, provisional designation 1991 JA1, is a binary Hungaria asteroid and very slow rotator from the inner regions of the asteroid belt, approximately 2 kilometers in diameter. It was discovered on 8 May 1991, by American astronomer Eleanor Helin at the U.S. Palomar Observatory, California.
The bright E-type asteroid is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.8–2.1 AU once every 2 years and 8 months (976 days). Its orbit has an eccentricity of 0.08 and an inclination of 20° with respect to the ecliptic. The fist observation was made at the discovering observatory in 1989, extending the asteroid's observation arc by almost 2 years prior to its discovery.
According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 1.7 kilometers in diameter and its surface has an exceptionally high albedo of 0.81, while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for Hungaria asteroids of 0.30, and calculates a diameter of 2.5 kilometers, based on an absolute magnitude of 14.9.
Two rotational light-curves were obtained for this asteroid from photometric observations by U.S. astronomer Brian D. Warner at the Palmer Divide Station (PDO), Colorado. In August 2010, the first light-curve gave a long rotation period of 7002372000000000000♠372±5 hours with a brightness variation of 1.0 in magnitude (U=3). The second light-curve from June 2015, gave a similar period of 7002355000000000000♠355±5 with an amplitude of 0.66 in magnitude (U=2).
In 2010 a small asteroid moon was discovered around this asteroid. It has an orbital period of 7000229999999999999♠2.300±0.001 hours, while observations at the PDO gave it a period of 2.2981 and 14.93 hours, respectively.
The minor planet was named in memory of NASA test pilot John B. McKay (1922–1975), one of the first pilots assigned to fly the North American X-15. He was also assigned to the X-1E and to the D-558-II. He died in 1975, from injuries he had sustained during a X-15 crash. In 2005, he received posthumous the astronaut badge for a reached peak-altitude of 89,900 metres (295,000 feet). Naming citation was published on 7 February 2012 (M.P.C. 78269).