1222 Tina

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1222 Tina
Discovery [1]
Discovered by E. Delporte
Discovery site Uccle Obs.
Discovery date 11 June 1932
MPC designation (1222) Tina
Named after
Tina (friend of the discoverer)[2]
1932 LA · 1955 HP
main-belt · (middle)[3]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 84.40 yr (30,827 days)
Aphelion 3.4912 AU
Perihelion 2.0983 AU
2.7947 AU
Eccentricity 0.2492
4.67 yr (1,707 days)
0° 12m 39.6s / day
Inclination 19.587°
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±0.003 h[9]
0.1445 (derived)[3]
SMASS = X[1] · M[8] · X[3]
10.3[5][7][8] · 11.2[1][3]

1222 Tina, provisional designation 1932 LA, is a metallic asteroid and parent body of the Tina family located in the intermediate asteroid belt, approximately 25 kilometers in diameter. It was discovered on 11 June 1932, by Belgian astronomer Eugène Delporte at Uccle Observatory in Belgium.[11] It was named after a friend of the discoverer.[2]

Classification and orbit[edit]

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.[12][13] 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 170+20
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 an eccentricity of 0.25 and an inclination of 20° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation as no precoveries were taken, and no prior identifications were made.[11]

Physical characteristics[edit]

Diameter and albedo[edit]

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).[5][6][7] 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.[3]

Spectral type[edit]

In the SMASS taxonomy, Tina is a X-type asteroid, while it is classified as a metal-rich M-type asteroid by the WISE-survey.[1][8]

Rotation period[edit]

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).[10] Other lightcurves 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).[9]


This minor planet was named after "Tina", an amateur astronomer and friend of the discoverer.[2] In 1955, naming citation was published by Paul Herget in The Names of the Minor Planets (H 114).[2]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 1222 Tina (1932 LA)" (2016-11-04 last obs.). Jet Propulsion Laboratory. Retrieved 26 January 2017. 
  2. ^ a b c d Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1222) Tina. Springer Berlin Heidelberg. p. 102. ISBN 978-3-540-00238-3. Retrieved 26 January 2017. 
  3. ^ a b c d e f "LCDB Data for (1222) Tina". Asteroid Lightcurve Database (LCDB). Retrieved 26 January 2017. 
  4. ^ a b Carruba, Valerio; et al. (November 2011), "On the first nu6 anti-aligned librating asteroid family of Tina", MNRAS, 418 (1), pp. 2040–2051, Bibcode:2011MNRAS.412.2040C, doi:10.1111/j.1365-2966.2010.18083.x 
  5. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. Bibcode:2004PDSS...12.....T. Retrieved 26 January 2017. 
  6. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645Freely accessible. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 26 January 2017. 
  7. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 26 January 2017. 
  8. ^ a b c d e Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 26 January 2017. 
  9. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (1222) Tina". Geneva Observatory. Retrieved 26 January 2017. 
  10. ^ a b Warner, Brian D. (June 2008). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory - June - October 2007". The Minor Planet Bulletin. 35 (2): 56–60. Bibcode:2008MPBu...35...56W. ISSN 1052-8091. Retrieved 26 January 2017. 
  11. ^ a b "1222 Tina (1932 LA)". Minor Planet Center. Retrieved 26 January 2017. 
  12. ^ Carruba, Valerio (June 2010), "The stable archipelago in the region of the Pallas and Hansa families", MNRAS, 408 (1), pp. 580–600, Bibcode:2010MNRAS.408..580C, doi:10.1111/j.1365-2966.2010.17146.x 
  13. ^ Novaković, Bojan; et al. (November 2011), "Families among high-inclination asteroids", Icarus, 216 (1), pp. 69–81, arXiv:1108.3740Freely accessible, Bibcode:2011Icar..216...69N, doi:10.1016/j.icarus.2011.08.016 

External links[edit]