5143 Heracles

5143 Heracles
Discovery [1]
Discovered by C. Shoemaker
Discovery site Palomar Obs.
Discovery date 7 November 1991
Designations
MPC designation (5143) Heracles
Named after
 Heracles (Greek mythology)[2]
1991 VL · 1962 PG
Apollo · NEO [1][3]
Orbital characteristics [1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 63.58 yr (23,224 days)
Aphelion 3.2494 AU
Perihelion 0.4174 AU
1.8334 AU
Eccentricity 0.7723
2.48 yr (907 days)
93.744°
0° 23m 49.2s / day
Inclination 9.0330°
309.52°
227.77°
Known satellites 1[4][5][6] (0.6±0.3 km; orb. 17 h)
Earth MOID 0.0584 AU · 22.8 LD
Physical characteristics
Dimensions 3.26 km[7]
3.28±0.09 km[8]
3.41 km[9]
4.5±0.7 km[4]
4.83 km (taken)[10]
4.833 km[11]
4.843±0.378 km[12][13]
2.704±0.002 h[14][lower-alpha 1]
2.7060±0.0002 h[15]
2.706±0.001 h[16]
2.7063 h[10]
2.7065±0.0005 h[4]
3.0149±0.0002 h[17]
5.990±0.0111 h[18]
0.1481[11]
0.20±0.05[4]
0.227±0.054[12][13]
0.38[9]
0.40±0.22[19]
0.412±0.030[8]
0.42[7]
SMASS = O [1]
Q [20] · C [21] · O [10]
V–R = 0.420±0.070[4]
13.786±0.004 (R)[18] · 13.8[12] · 14.0[1][7][8][21] · 14.10±0.04[4] · 14.27[10][22] · 14.27±0.09[11] · 14.52±0.02 (R)[15]

    5143 Heracles, provisional designation 1991 VL, is a highly eccentric, rare-type asteroid and synchronous binary system, classified as near-Earth object of the Apollo group, approximately 4.8 kilometers in diameter. The asteroid was discovered on 7 November 1991, by American astronomer Carolyn Shoemaker at Palomar Observatory in California, United States.[3] It is named for the Greek divine hero Heracles.[2]

    Classification and orbit

    Heracles orbits the Sun in the inner main-belt at a distance of 0.4–3.2 AU once every 2 years and 6 months (907 days). Its orbit has an eccentricity of 0.77 and an inclination of 9° with respect to the ecliptic.[1] The first precovery was taken at Palomar during the Digitized Sky Survey in 1953, extending the body's observation arc by 38 years prior to its official discovery observation.[3]

    Due to its high eccentricity, Heracles is also a Mercury-grazer and a Mars-crosser. It has an Earth minimum orbital intersection distance of 0.0584 AU (8,740,000 km) which corresponds to 22.8 lunar distances.[1]

    Physical characteristics

    Spectral type

    In the SMASS taxonomy, Heracles is a rare O-type asteroid, which have spectra similar to those of stony chondritic meteorites of the L6 and LL6 type.[1] However, it has also been characterized as a carbonaceous C-type, as well as a stony Sk and Q-type asteroid.[20][21][23]

    Lightcurves

    A large number of rotational lightcurves of Heracles were obtained from photometric observations between 2006 and 2016. Best rated lightcurves gave a rotation period between 2.7051 and 2.7065 hours with a brightness variation of 0.05 to 0.20magnitude (U=3/3/3/3/3-).[4][10][14][15][lower-alpha 1]

    Diameters

    According to the surveys carried out by the Spitzer Space Telescope, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, the asteroid measures between 3.26 and 4.843 kilometers in diameter, and its surface has an albedo between 0.20 and 0.24.[7][8][9][12] The Collaborative Asteroid Lightcurve Link adopts the results from Petr Pravec's revised WISE data, that is, an albedo of 0.1481 and a diameter of 4.83 kilometers with an absolute magnitude of 14.27.[10][11]

    Binary system

    On 12 July 2012, it was announced that Heracles is an assumed synchronous binary asteroid with a minor-planet moon orbiting its primary in a retrograde motion approximately every 16 hours. The companion was discovered in December 2011, by a team of astronomers using radar observations from Arecibo Observatory in Puerto Rico, following months of intensive photometric lightcurve observations (see above). It was designated S/2011 (5143) 1.

    A longer orbital period of 40–57 hours cannot be excluded, which would then no-longer be a synchronous system. Estimated diameters for Heracles and its moon are 3.6±1.2 and 0.6±0.3 kilometer, respectively.[5][6][10]

    Follow-up observations in 2016 confirmed an orbital period of 17 hours for the asteroid moon.[23]

    Naming

    This minor planet was named after Heracles, the divine gatekeeper of the Olympus and one of the greatest heroes in Greek mythology, known for his strength and his Twelve Labors. Heracles is the son of Zeus and Alcmena, after whom the asteroids 5731 Zeus and 82 Alkmene were named. In the Roman adaptation, Heracles is known as Hercules.[2] The approved naming citation was published by the Minor Planet Center on 14 July 1992 (M.P.C. 20523).[24]

    Notes

    1. 1 2 Warner (2017c): lightcurve plot of (5143) Heracles, with a rotation period 2.704±0.002 hours and a brightness amplitude of 0.15 mag (Quality Code of 2; 133 points). Observations from 12 to 17 September 2016, at CS3-Palmer Divide Station. Summary figures at Collaborative Asteroid Lightcurve Link (CALL)

    References

    1. 1 2 3 4 5 6 7 8 "JPL Small-Body Database Browser: 5143 Heracles (1991 VL)" (2017-07-01 last obs.). Jet Propulsion Laboratory. Retrieved 4 July 2017.
    2. 1 2 3 Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (5143) Heracles. Springer Berlin Heidelberg. p. 442. ISBN 978-3-540-00238-3. Retrieved 14 March 2017.
    3. 1 2 3 "5143 Heracles (1991 VL)". Minor Planet Center. Retrieved 14 March 2017.
    4. 1 2 3 4 5 6 7 Pilcher, Frederick; Briggs, John W.; Franco, Lorenzo; Inasaridze, Raguli Ya.; Krugly, Yurij N.; Molotiv, Igor E.; et al. (July 2012). "Rotation Period Determination for 5143 Heracles". The Minor Planet Bulletin. 39 (3): 148–151. Bibcode:2012MPBu...39..148P. ISSN 1052-8091. Retrieved 14 March 2017.
    5. 1 2 Taylor, P. A.; Nolan, M. C.; Howell, E. S. (July 2012). "(5143) Heracles". Central Bureau Electronic Telegrams (3176). Bibcode:2012CBET.3176....1T. Retrieved 14 March 2017.
    6. 1 2 Lance A. M. Benner (2013-11-18). "Binary and Ternary near-Earth Asteroids detected by radar". NASA/JPL Asteroid Radar Research. Retrieved 14 March 2017.
    7. 1 2 3 4 Trilling, D. E.; Mueller, M.; Hora, J. L.; Harris, A. W.; Bhattacharya, B.; Bottke, W. F.; et al. (September 2010). "ExploreNEOs. I. Description and First Results from the Warm Spitzer Near-Earth Object Survey". The Astronomical Journal. 140 (3): 770–784. Bibcode:2010AJ....140..770T. doi:10.1088/0004-6256/140/3/770. Retrieved 14 March 2017.
    8. 1 2 3 4 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 14 March 2017.
    9. 1 2 3 Harris, A. W.; Mommert, M.; Hora, J. L.; Mueller, M.; Trilling, D. E.; Bhattacharya, B.; et al. (March 2011). "ExploreNEOs. II. The Accuracy of the Warm Spitzer Near-Earth Object Survey". The Astronomical Journal. 141 (3): 10. Bibcode:2011AJ....141...75H. doi:10.1088/0004-6256/141/3/75. Retrieved 14 March 2017.
    10. 1 2 3 4 5 6 7 "LCDB Data for (5143) Heracles". Asteroid Lightcurve Database (LCDB). Retrieved 14 March 2017.
    11. 1 2 3 4 Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 14 March 2017.
    12. 1 2 3 4 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 14 March 2017.
    13. 1 2 Mainzer, A.; Grav, T.; Bauer, J.; Masiero, J.; McMillan, R. S.; Cutri, R. M.; et al. (December 2011). "NEOWISE Observations of Near-Earth Objects: Preliminary Results". The Astrophysical Journal. 743 (2): 17. arXiv:1109.6400. Bibcode:2011ApJ...743..156M. doi:10.1088/0004-637X/743/2/156. Retrieved 14 March 2017.
    14. 1 2 Warner, Brian D. (January 2017). "Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2016 July-September". The Minor Planet Bulletin. 44 (1): 22–36. Bibcode:2017MPBu...44...22W. ISSN 1052-8091. Retrieved 4 July 2017.
    15. 1 2 3 Polishook, David (July 2012). "Lightcurves and Spin Periods of Near-Earth Asteroids, The Wise Observatory, 2005 - 2010". The Minor Planet Bulletin. 39 (3): 187–192. Bibcode:2012MPBu...39..187P. ISSN 1052-8091. Retrieved 14 March 2017.
    16. ↑ Linder, Tyler R.; Sampson, Ryan; Holmes, Robert (January 2013). "Astronomical Research Institute Photometric Results". The Minor Planet Bulletin. 40 (1): 4–6. Bibcode:2013MPBu...40....4L. ISSN 1052-8091. Retrieved 14 March 2017.
    17. ↑ Behrend, Raoul. "Asteroids and comets rotation curves – (5143) Heracles". Geneva Observatory. Retrieved 14 March 2017.
    18. 1 2 Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 14 March 2017.
    19. ↑ 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 7 January 2017.
    20. 1 2 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 7 January 2017.
    21. 1 2 3 Carry, B.; Solano, E.; Eggl, S.; DeMeo, F. E. (April 2016). "Spectral properties of near-Earth and Mars-crossing asteroids using Sloan photometry". Icarus. 268: 340–354. arXiv:1601.02087. Bibcode:2016Icar..268..340C. doi:10.1016/j.icarus.2015.12.047. Retrieved 14 March 2017.
    22. ↑ Pravec, Petr; Wolf, Marek; Sarounová, Lenka (November 1998). "Lightcurves of 26 Near-Earth Asteroids". Icarus. 136 (1): 124–153. Bibcode:1998Icar..136..124P. doi:10.1006/icar.1998.5993. Retrieved 14 March 2017.
    23. 1 2 Taylor, P. A.; Howell, E. S.; Zambrano-Marin, L. F. (2017). "Radar and infrared Observations of Binary Near-Earth Asteroid (5143) Heracles" (PDF). Retrieved 14 March 2017.
    24. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 14 March 2017.
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