1685 Toro

1685 Toro
Discovery [1]
Discovered by C. A. Wirtanen
Discovery site Lick Obs.
Discovery date 17 July 1948
Designations
MPC designation (1685) Toro
Named after
 Betulia Toro Herrick
(wife Samuel Herrick)[2]
1948 OA
NEO · Apollo [1][3]
Mars-crosser
Orbital characteristics [1]
Epoch 6 January 2008 (JD 2454471.5)
Uncertainty parameter 0
Observation arc 68.75 yr (25,111 days)
Aphelion 1.9630 AU
Perihelion 0.7712 AU
1.3671 AU
Eccentricity 0.4359
1.60 yr (584 days)
18.420°
Inclination 9.3815°
274.34°
127.07°
Earth MOID 0.0506 AU · 19.7 LD
Physical characteristics
Dimensions 3.810±0.049 km[4]
4.1 km[5]
10.185±0.003 h[6]
10.1862±0.0006 h[7]
10.191±0.005 h[8]
10.195 h[9]
10.19540 h[10]
10.196 h[11]
10.199±0.003 h[12]
10.1995±0.0004 h[13]
10.203±0.003 h[14]
0.247±0.049[4]
0.29[5]
0.38±0.33[15]
S (Tholen)[1] · S (SMASS)[1] · S [16][17]
B–V = 0.880[1]
U–B = 0.470[1]
13.90[5][17] · 14.02±1.11[18] · 14.23[1][4]

    1685 Toro, provisional designation 1948 OA, is an eccentric stony asteroid and near-Earth object of the Apollo group, approximately 4 kilometers in diameter. It was discovered on 17 July 1948, by American astronomer Carl Wirtanen at Lick Observatory on Mount Hamilton, California.[3][19] It is named for Betulia Toro Herrick, wife of astronomer Samuel Herrick.[2]

    Classification and orbit

    Toro is an Apollo asteroid, a subgroup of near-Earth asteroids that cross the orbit of Earth. It orbits the Sun at a distance of 0.8–2.0 AU once every 1 year and 7 months (584 days). Its orbit has an eccentricity of 0.44 and an inclination of 9° with respect to the ecliptic.[1]

    This asteroid's orbit also shows a 5:8 resonance with Earth[20] and in a near 5:13 resonance with Venus. It was the third Apollo asteroid to be discovered. The current resonance with Earth will last for only a few thousand years. Calculations show that Toro will leave it in 2960 CE, and that it will enter the region of 5:13 resonance with Venus in 3470 CE. This is because the distance from Earth's orbit will become larger and that from Venus's orbit smaller. A study of long-term stability shows that the alternating resonances will possibly be broken roughly 3 million years from now because of close approaches between Toro and Mars.[21]

    Based on orbital paths, Toro is the best candidate for the source of the Sylacauga meteorite, the first meteorite authenticated to have struck a human, Mrs. Ann Hodges of Sylacauga, Alabama on 30 November 1954.[22] Toro's Earth minimum orbit intersection distance of 0.0506 AU (7,570,000 km),[1] is just above the 0.05 AU requirement to be listed as a potentially hazardous asteroid. With an orbital uncertainty U = 0, its orbit and future close approaches are well determined.[1]

    Physical characteristics

    In the Tholen and SMASS taxonomic scheme, Toro is characterized as a stony S-type asteroid.[1] It is reported to be composed of L chondrite[23] with a high albedo in the range of 0.24–0.34 . It has an extremely well-measured rotation period of 10.2 hours.[6][7][9][10][11][12][13]

    Naming

    This minor planet was named after the maiden name of Betulia Herrick, wife of American astronomer Samuel Herrick. Herrick had studied the asteroid's orbit, and requested the name, along with the other asteroid, 1580 Betulia.[24] University of California,[25] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 2504).[26]

    References

    1. 1 2 3 4 5 6 7 8 9 10 11 12 "JPL Small-Body Database Browser: 1685 Toro (1948 OA)" (2017-04-17 last obs.). Jet Propulsion Laboratory. Retrieved 6 June 2017.
    2. 1 2 Schmadel, Lutz D. (2007). "(1685) Toro". Dictionary of Minor Planet Names – (1685) Toro. Springer Berlin Heidelberg. p. 134. doi:10.1007/978-3-540-29925-7_1686. ISBN 978-3-540-00238-3. Retrieved 22 December 2016.
    3. 1 2 "1685 Toro (1948 OA)". Minor Planet Center. Retrieved 22 December 2016.
    4. 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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 22 December 2016.
    5. 1 2 3 Harris, Alan W. (February 1998). "A Thermal Model for Near-Earth Asteroids". Icarus. 131 (2): 291–301. Bibcode:1998Icar..131..291H. doi:10.1006/icar.1997.5865. Retrieved 22 December 2016.
    6. 1 2 Warner, Brian D. (January 2013). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2012 June – September". The Minor Planet Bulletin. 40 (1): 26–29. Bibcode:2013MPBu...40...26W. ISSN 1052-8091. Retrieved 22 December 2016.
    7. 1 2 Higgins, David; Pravec, Petr; Kusnirak, Peter; Hornoch, Kamil; Brinsfield, James W.; Allen, Bill; et al. (September 2008). "Asteroid Lightcurve Analysis at Hunters Hill Observatory and Collaborating Stations: November 2007 – March 2008". The Minor Planet Bulletin. 35 (3): 123–126. Bibcode:2008MPBu...35..123H. ISSN 1052-8091. Retrieved 22 December 2016.
    8. ↑ Warner, Brian D. (July 2016). "Near-Earth Asteorid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 January–April". The Minor Planet Bulletin. 43 (3): 240–250. Bibcode:2016MPBu...43..240W. ISSN 1052-8091. Retrieved 22 December 2016.
    9. 1 2 Torppa, J.; Aksnes, K.; Dai, Z.; Grav, T.; Hahn, G.; Laakso, T.; et al. (August 2005). "Spins and Shapes of Potentially Hazardous Asteroids". American Astronomical Society. 37: 643. Bibcode:2005DPS....37.1526T. Retrieved 22 December 2016.
    10. 1 2 De Angelis, G. (May 1995). "Asteroid spin, pole and shape determinations". Planetary and Space Science. 43 (5): 649–682. Bibcode:1995P&SS...43..649D. doi:10.1016/0032-0633(94)00151-G. Retrieved 22 December 2016.
    11. 1 2 Dunlap, J. L.; Gehrels, T.; Howes, M. L. (August 1973). "Minor planets and related objects. IX. Photometry and polarimetry of (1685) Toro". Astronomical Journal. 78: 491. Bibcode:1973AJ.....78..491D. doi:10.1086/111447. Retrieved 22 December 2016.
    12. 1 2 Higgins, David (January 2011). "Period Determination of Asteroid Targets Observed at Hunters Hill Observatory: May 2009 – September 2010". The Minor Planet Bulletin. 38 (1): 41–46. Bibcode:2011MPBu...38...41H. ISSN 1052-8091. Retrieved 22 December 2016.
    13. 1 2 Higgins, David (March 2008). "Asteroid Lightcurve Analysis at Hunters Hill Observatory and Collaborating Stations: April 2007 – June 2007". The Minor Planet Bulletin. 35 (1): 30–32. Bibcode:2008MPBu...35...30H. ISSN 1052-8091. Retrieved 22 December 2016.
    14. ↑ Oey, Julian (October 2011). "Lightcurve Analysis of Asteroids from Leura and Kingsgrove Observatory for the Second Half of 2009 and 2010". The Minor Planet Bulletin. 38 (4): 221–223. Bibcode:2011MPBu...38..221O. ISSN 1052-8091. Retrieved 22 December 2016.
    15. ↑ Thomas, C. A.; Trilling, D. E.; Emery, J. P.; Mueller, M.; Hora, J. L.; Benner, L. A. M.; et al. (September 2011). "ExploreNEOs. V. Average Albedo by Taxonomic Complex in the Near-Earth Asteroid Population". The Astronomical Journal. 142 (3): 12. Bibcode:2011AJ....142...85T. doi:10.1088/0004-6256/142/3/85. Retrieved 22 December 2016.
    16. ↑ Thomas, Cristina A.; Emery, Joshua P.; Trilling, David E.; Delbó, Marco; Hora, Joseph L.; Mueller, Michael (January 2014). "Physical characterization of Warm Spitzer-observed near-Earth objects". Icarus. 228: 217–246. arXiv:1310.2000. Bibcode:2014Icar..228..217T. doi:10.1016/j.icarus.2013.10.004. Retrieved 22 December 2016.
    17. 1 2 "LCDB Data for (1685) Toro". Asteroid Lightcurve Database (LCDB). Retrieved 22 December 2016.
    18. ↑ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 – Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 22 December 2016.
    19. ↑ Waldemar Kaempffert (26 December 1948). "Science in Review: Research Work in Astronomy and Cancer Lead Year's List of Scientific Developments". The New York Times. p. 87. ISSN 0362-4331. Retrieved 4 August 2011.
    20. ↑ Danielsson, L.; Ip, W.-H. (May 1972). "Capture Resonance of the Asteroid 1685 Toro by the Earth". Science. 176 (4037): 906–907. Bibcode:1972Sci...176..906D. doi:10.1126/science.176.4037.906. PMID 17829299. Retrieved 22 December 2016.
    21. ↑ Williams, J. G.; Wertherill, G. W. (August 1973). "Minor planets and related objects. XIII. Long-term orbital evolution of (1685) Toro". Astronomical Journal. 78: 510. Bibcode:1973AJ.....78..510W. doi:10.1086/111451.
    22. ↑ Povenmire, H. (March 1995). "The Sylacauga, Alabama Meteorite: The Impact Locations, Atmosphere Trajectory, Strewn Field and Radiant". Abstracts of the Lunar and Planetary Science Conference. Bibcode:1995LPI....26.1133P. Retrieved 22 December 2016.
    23. ↑ Hartmann, W. K. (2005). Moons & Planets (5th ed.). Belmont, Calif.: Brooks/Cole. ASIN 0534493939
    24. ↑ Schmadel, Lutz D. (2007). "(1580) Betulia". Dictionary of Minor Planet Names – (1580) Betulia. Springer Berlin Heidelberg. p. 125. doi:10.1007/978-3-540-29925-7_1581. ISBN 978-3-540-00238-3. Retrieved 22 December 2016.
    25. ↑ "Samuel Herrick, Engineering; Astronomy: Los Angeles". Calisphere – University of California. Retrieved 22 December 2016.
    26. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 22 December 2016.
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