1842 Hynek, provisional designation 1972 AA, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter.

1842 Hynek
Discovery[1]
Discovered byL. Kohoutek
Discovery siteHamburg Observatory
Discovery date14 January 1972
Designations
(1842) Hynek
Named after
Hynek Kohoutek
(father of discoverer)[2]
1972 AA · 1928 DE
1929 SO · 1952 DN2
1953 UV · 1962 EA
1963 SS · 1964 YF
1966 HE · 1969 EG1
2004 TE363
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.59 yr (31,992 days)
Aphelion2.6758 AU
Perihelion1.8568 AU
2.2663 AU
Eccentricity0.1807
3.41 yr (1,246 days)
339.54°
0° 17m 20.04s / day
Inclination5.3539°
153.45°
125.55°
Physical characteristics
Dimensions7.996±0.073[4]
8.171±0.027 km[5]
9.31±1.70 km[6]
9.80 km (calculated)[3]
3.94±0.02 h[7]
3.9410±0.0007 h[7]
0.20 (assumed)[3]
0.28±0.14[6]
0.2899±0.0415[5]
0.300±0.073[4]
Tholen = S[1] · S[3][8]
B–V = 0.871[1]
U–B = 0.522[1]
12.41[1][3][5][6] · 12.89±0.41[8]

The asteroid was discovered on 14 January 1972 by Czech astronomer Luboš Kohoutek at Hamburg Observatory, who named it after his father, Hynek Kohoutek.[9]

Orbit and classification

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Hynek is member of the Flora family. It orbits the Sun in the inner main-belt at a distance of 1.9–2.7 AU once every 3 years and 5 months (1,246 days). Its orbit has an eccentricity of 0.18 and an inclination of 5° with respect to the ecliptic.[1]

First identified as 1928 DE at Heidelberg, the asteroid's observation arc begins with its first used observation taken at Lowell Observatory in 1929, when it was identified as 1929 SO, nearly 43 years prior to its official discovery observation at Hamburg.[9]

Physical characteristics

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In the Tholen classification, Hynek is characterized as a common S-type asteroid.[1]

Rotation period

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In July 2007, the so-far best rated rotational lightcurve of Hynek was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a well-defined rotation period of 3.9410 hours with a brightness variation of 0.17 magnitude (U=3).[7]

Diameter and albedo

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According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Hynek measures between 7.996 and 9.31 kilometers in diameter, and its surface has an albedo between 0.28 of 0.300.[4][5][6]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 9.80 kilometers with an absolute magnitude of 12.41.[3]

Naming

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This minor planet was named after Hynek Kohoutek, the father of the discoverer, celebrating his 70th birthday.[2] The official naming citation was published by the Minor Planet Center on 20 December 1974 (M.P.C. 3757).[10]

References

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  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1842 Hynek (1972 AA)" (2017-05-02 last obs.). Jet Propulsion Laboratory. Archived from the original on 15 March 2017. Retrieved 8 June 2017.
  2. ^ a b Schmadel, Lutz D. (2007). "(1842) Hynek". Dictionary of Minor Planet Names – (1842) Hynek. Springer Berlin Heidelberg. p. 148. doi:10.1007/978-3-540-29925-7_1843. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1842) Hynek". Asteroid Lightcurve Database (LCDB). Retrieved 14 March 2017.
  4. ^ 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:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 14 March 2017.
  5. ^ a b c d 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:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  6. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 14 March 2017.
  7. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (1842) Hynek". Geneva Observatory. Retrieved 14 March 2017.
  8. ^ a b 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 14 March 2017.
  9. ^ a b "1842 Hynek (1972 AA)". Minor Planet Center. Retrieved 14 March 2017.
  10. ^ Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
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