| Discovery[1] | |
|---|---|
| Discovered by | E. Delporte |
| Discovery site | Uccle Obs. |
| Discovery date | 11 June 1932 |
| Designations | |
| (1222) Tina | |
Named after | Tina(friend of the discoverer)[2] |
| 1932 LA · 1955 HP | |
| main-belt · (middle)[3] Tina[4] | |
| Orbital characteristics[1] | |
| Epoch 16 February 2017 (JD 2457800.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 84.40 yr (30,827 days) |
| Aphelion | 3.4912AU |
| Perihelion | 2.0983 AU |
| 2.7947 AU | |
| Eccentricity | 0.2492 |
| 4.67yr (1,707 days) | |
| 31.083° | |
| 0° 12m 39.6s / day | |
| Inclination | 19.587° |
| 245.80° | |
| 59.912° | |
| Physical characteristics | |
| Dimensions | 20.12 km(derived)[3] 20.84±1.8 km[5] 25.781±0.138 km[6] 26.28±0.33 km[7] 28.667±0.122 km[8] |
| 12 h(dated)[9] 13.395±0.003 h[10] 17.164±0.003h[9] | |
| 0.1445(derived)[3] 0.1645±0.0191[8] 0.199±0.006[7] 0.202±0.045[6] 0.3086±0.059[5] | |
| SMASS =X[1] · M[8] · X[3] | |
| 10.3[5][7][8] · 11.2[1][3] | |
1222 Tina, provisional designation1932 LA, is a metallicasteroid and parent body of theTina family located in the intermediateasteroid belt, approximately 25 kilometers in diameter. It was discovered on 11 June 1932, by Belgian astronomerEugène Delporte atUccle Observatory in Belgium.[11] It was named after a friend of the discoverer.[2]
Tina is the namesake of theTina family a group of 17–89 asteroids that form a small, well-definedasteroid family, which share similarspectral properties andorbital elements; hence they may have arisen from the same collisional event of two larger parent bodies. All members have a relatively highorbital inclination.[12][13] The Tina family is unique because of its resonant nature: all its members are in anti-aligned librating states of theν6 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, about170+20
−30 million years old, and will most likely disperse to unstable regions in timescales of 200 million years.[4]
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 aneccentricity of 0.25 and aninclination of 20° with respect to theecliptic.[1] The body'sobservation arc begins with its official discovery observation as noprecoveries were taken, and no prior identifications were made.[11]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Tina measures between 20.84 and 26.28 kilometers in diameter and its surface has analbedo between 0.199 and 0.308 (without preliminary results).[5][6][7] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.1445 and a diameter of 20.12 kilometers using anabsolute magnitude of 11.2.[3]
In theSMASS taxonomy,Tina is anX-type asteroid, while it is classified as a metal-richM-type asteroid by the WISE-survey.[1][8]
Tina has a well-definedrotation period of 13.395 hours with a brightness variation of 0.18magnitude (U=3), derived from photometric observations taken by American astronomerBrian Warner at his Palmer Divide Observatory, Colorado, in September 2007(also see§ External links).[10] Otherlightcurves were obtained by French amateur astronomersPierre Antonini and Jean-Gabriel Bosch, which gave a period of 17.164 hours and an amplitude of 0.30 magnitude (U=2/2).[9]
Thisminor planet was named after "Tina", an amateur astronomer and friend of the discoverer.[2] In 1955, naming citation was published byPaul Herget inThe Names of the Minor Planets (H 114).[2]
