6469 Armstrong, provisional designation 1982 PC, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered by Czech astronomer Antonín Mrkos at Kleť Observatory on 14 August 1982.[8] The asteroid was later named for American astronaut Neil Armstrong.[2]

6469 Armstrong
Discovery [1]
Discovered byA. Mrkos
Discovery siteKleť Obs.
Discovery date14 August 1982
Designations
(6469) Armstrong
Named after
Neil Armstrong
(astronaut, Apollo 11)[2]
1982 PC · 1969 UK1
1972 NN · 1979 WZ6
1982 QL
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc47.45 yr (17,332 days)
Aphelion2.6725 AU
Perihelion1.7663 AU
2.2194 AU
Eccentricity0.2041
3.31 yr (1,208 days)
226.43°
0° 17m 53.16s / day
Inclination3.9595°
159.41°
150.61°
Physical characteristics
Dimensions2.89 km (calculated)[3]
3.720±0.392 km[4][5]
5.9648±0.1423 h[6]
6.040±0.040 h[7]
0.24 (assumed)[3]
0.243±0.039[4][5]
S[3]
14.5[1] · 14.340±0.250 (R)[7] · 14.3[4] · 14.416±0.007 (R)[6] · 14.87[3]

Orbit and classification

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Armstrong is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,208 days). Its orbit has an eccentricity of 0.20 and an inclination of 4° with respect to the ecliptic.[1]

In October 1969, it was first identified as 1969 UK1 at Crimea–Nauchnij. The body's observation arc began 10 years prior to its official discovery at Klet Observatory, with a precovery taken at Crimea–Nauchnij in July 1972.[8]

Physical characteristics

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Armstrong is a presumed S-type asteroid.[3]

Rotation period

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Two rotational lightcurves of Armstrong were obtained from photometric observations made at the Palomar Transient Factory, California, in January and February 2014. The lightcurves gave a concurring rotation period of 6.040±0.040 and 5.9648±0.1423 hours with a brightness variation of 0.65 and 0.70 in magnitude, respectively (U=2/2).[7][6]

Diameter and albedo

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According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Armstrong measures 3.7 kilometers in diameter and its surface has an albedo of 0.24.[4][5]

The Collaborative Asteroid Lightcurve Link assumes an identical albedo of 0.24 – derived from 8 Flora, the largest member and namesake of its orbital family – and calculates a diameter of 2.9 kilometers, based on a weaker absolute magnitude of 14.87.[3]

Naming

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This minor planet was named after American astronaut Neil Armstrong, on the occasion of the 30th anniversary of the Apollo 11 mission.[2]

On 20 July 1969, Armstrong was one of the first two humans to land on the Moon, and the first person to walk on it, shortly followed by Buzz Aldrin, after whom the asteroid 6470 Aldrin is named. The minor planet 6471 Collins is named after Michael Collins, the third crew member of the Apollo 11 mission. In 1966, Armstrong also conducted the first docking in space together with David Scott aboard Gemini 8. The asteroid's name was suggested by Czech astronomers Jana Tichá, Miloš Tichý and Zdeněk Moravec, who observed it during its 1995-opposition, shortly before being numbered.[2] The approved naming citation was published by the Minor Planet Center on 4 May 1999 (M.P.C. 34623).[9]

The lunar crater Armstrong is also named in his honor.

References

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  1. ^ a b c d "JPL Small-Body Database Browser: 6469 Armstrong (1982 PC)" (2017-03-30 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(6469) Armstrong". Dictionary of Minor Planet Names – (6469) Armstrong. Springer Berlin Heidelberg. pp. 534–535. doi:10.1007/978-3-540-29925-7_5888. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (6469) Armstrong". Asteroid Lightcurve Database (LCDB). Retrieved 10 May 2016.
  4. ^ 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. S2CID 35447010. Retrieved 10 May 2016.
  5. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. S2CID 118745497. Retrieved 5 December 2016.
  6. ^ a b c 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. S2CID 8342929. Retrieved 10 May 2016.
  7. ^ a b c Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; et al. (August 2015). "Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory". The Astrophysical Journal Supplement Series. 219 (2): 19. arXiv:1506.08493. Bibcode:2015ApJS..219...27C. doi:10.1088/0067-0049/219/2/27. S2CID 17093124. Retrieved 10 May 2016.
  8. ^ a b "6469 Armstrong (1982 PC)". Minor Planet Center. Retrieved 10 May 2016.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 10 May 2016.
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