Discovered by E. Delporte MPC designation 1222 Tina Observation arc 84.40 yr (30,827 days) Orbits Sun Named after Eugène Joseph Delporte | Discovery date 11 June 1932 Alternative names 1932 LA · 1955 HP Discovered 11 June 1932 Discoverer Eugène Joseph Delporte Asteroid group Asteroid belt | |
Minor planet category main-belt · (middle)
Tina family Discovery site Royal Observatory of Belgium Similar Asteroid belt, Sun, Solar System, 1221 Amor, 2101 Adonis | ||
1222 Tina, provisional designation 1932 LA, is a metallic asteroid from the middle region of the asteroid belt, approximately 25 kilometers in diameter. It was discovered on 11 June 1932, by Belgian astronomer Eugène Delporte at Uccle Observatory in Belgium. It was named after a fried of the discoverer.
Description
The X-type asteroid is classified as a metal-rich M-type asteroid. It orbits the Sun at a distance of 2.1–3.5 AU once every 4 years and 8 months (1,707 days). Its orbit has an eccentricity of 0.25 and an inclination of 20° with respect to the ecliptic. The body's observation arc begins with its official discovery observation as no precoveries were taken, and no prior identifications were made.
Tina has a well-defined rotation period of 13.395 hours with a brightness variation of 0.18 magnitude (U=3), derived from photometric observations taken by American astronomer Brian Warner at his Palmer Divide Observatory, Colorado, in September 2007 (also see § External links). Other light curves were obtained by French amateur astronomers Pierre Antonini and Jean-Gabriel Bosch, which gave a period of 17.164 hours and an amplitude of 0.30 magnitude (U=2/2).
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Tina measures between 20.84 and 26.28 kilometers in diameter and its surface has an albedo between 0.199 and 0.308 (without preliminary results). The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1445 and a diameter of 20.12 kilometers using an absolute magnitude of 11.2.
Tina is the namesake of the Tina family a group of 17–89 asteroids that form a small, well-defined asteroid family, which share similar spectral properties and orbital elements; hence they may have arisen from the same collisional event of two larger parent bodies. All members have a relatively high orbital inclination. The Tina family is unique because of its resonant nature: all its members are in anti-aligned librating states of the ν6 secular resonance, i.e., the longitudes of pericenter of the asteroids follow the longitudes of pericenter of Saturn by 180 degrees. This orbital configuration protects the asteroids from achieving high eccentricities and experiencing close encounters with terrestrial planets, forming a stable in a region strongly perturbed by the ν6 secular resonance. The family is estimated to be relatively young, about 7002170000000000000♠170+20
−30 million years old, and will most likely disperse to unstable regions in timescales of 200 million years.
This minor planet was named after "Tina", an amateur astronomer and friend of the discoverer. In 1955, naming citation was published by Paul Herget in The Names of the Minor Planets (H 114).