1222 Tina

1222 Tina
Discovery [1]
Discovered by E. Delporte
Discovery site Uccle – Belgium
Discovery date 11 June 1932
Designations
MPC designation 1222 Tina
Named after
 Tina
(friend of)
Eugène Delporte[2]
1932 LA · 1955 HP
main-belt · (outer) [3]
Tina family[4]
Orbital characteristics [1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 83.82 yr (30616 days)
Aphelion 3.4905 AU (522.17 Gm)
Perihelion 2.0983 AU (313.90 Gm)
2.7944 AU (418.04 Gm)
Eccentricity 0.24910
4.67 yr (1706.2 d)
348.89°
0° 12m 39.6s / day
Inclination 19.587°
245.80°
59.907°
Earth MOID 1.15035 AU (172.090 Gm)
Jupiter MOID 1.91712 AU (286.797 Gm)
Jupiter Tisserand parameter 3.199
Physical characteristics
Dimensions 20.84 km[5]
26.28±0.33 km[6]
28.667±0.122 km[7]
20.12 km (derived)[3]
Mean radius
 10.42±0.9 km
13.395 h (0.5581 d)[1][8]
17.164±0.003 h[9]
12 h[9]
0.3086[5]
0.199±0.006[6]
0.1645±0.0191[7]
0.1445 (derived)[3]
0.3086±0.059[1]
SMASS = X
X [3]
11.2

    1222 Tina, provisional designation 1932 LA, is an eccentric, metallic asteroid from the outer region of the asteroid belt, about 21 kilometers in diameter. It was discovered by Belgian astronomer Eugène Joseph Delporte at Royal Observatory of Belgium in Uccle on 11 June 1932.[10]

    The X-type asteroid orbits the Sun at a distance of 2.1–3.5 AU once every 4 years and 8 months (1,707 days). Its orbit shows an eccentricity of 0.25 and is tilted by 20 degrees to the plane of the ecliptic. It has a rotation period of 13.4 and 17.2 hours as observed at the Palmer Divide Observatory (also see § External links) and by Pierre Antonini, respectively.[8][9] It has an albedo of 0.16–0.31, according to the surveys carried out by the space-based satellites IRAS, Akari, and WISE. This would place the body into the subgroup of metallic M-type asteroids (Akari and WISE, albedo lower than 0.02) or into the E-type subgroup (IRAS, albedo above 0.30).[5][6][7]

    The body 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.[11][12]

    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
    −30     million years old, and will most likely disperse to unstable regions in timescales of 200 million years.[4]

    The minor planet was named after "Tina", a female amateur astronomer and friend of the discoverer.[2]

    References

    1. 1 2 3 4 "JPL Small-Body Database Browser: 1222 Tina (1932 LA)" (2015-08-07 last obs.). Jet Propulsion Laboratory. Retrieved 30 April 2016.
    2. 1 2 Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (1222) Tina. Springer Berlin Heidelberg. p. 102. ISBN 978-3-540-29925-7. Retrieved 22 November 2015.
    3. 1 2 3 4 "LCDB Data for (1222) Tina". Asteroid Lightcurve Database (LCDB). Retrieved 22 November 2015.
    4. 1 2 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. 1 2 3 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 22 November 2015.
    6. 1 2 3 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 22 November 2015.
    7. 1 2 3 Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 22 November 2015.
    8. 1 2 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 22 November 2015.
    9. 1 2 3 Behrend, Raoul. "Asteroids and comets rotation curves – (1222) Tina". Geneva Observatory. Retrieved 22 November 2015.
    10. ↑ "1222 Tina (1932 LA)". Minor Planet Center. Retrieved 22 November 2015.
    11. ↑ 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
    12. ↑ 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

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