1658 Innes

1658 Innes
Discovery[1]
Discovered byJ. A. Bruwer
Discovery siteJohannesburg Obs.
Discovery date13 July 1953
Designations
(1658) Innes
Named after
Robert T. A. Innes
(astronomer)[2]
1953 NA · 1940 GB
1948 EM · 1949 QA
1953 OF · 1953 PN
1957 OE
main-belt · (middle)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc77.08 yr (28,155 days)
Aphelion3.0302 AU
Perihelion2.0866 AU
2.5584 AU
Eccentricity0.1844
4.09 yr (1,495 days)
247.27°
0° 14m 27.24s / day
Inclination9.0941°
95.441°
188.76°
Physical characteristics
Dimensions13.352±0.140 km[3]
13.54±1.17 km[4]
14.082±0.042 km[5]
14.76 km (calculated)[6]
3.191±0.001 h[7][8]
0.20 (assumed)[6]
0.2241±0.0369[5]
0.248±0.019[3]
0.626±0.318[4]
B–V = 0.960[1]
U–B = 0.610[1]
Tholen = AS[1] · AS[6]
11.27±0.41[9] · 10.47[4] · 11.52[1][6][5]

1658 Innes, provisional designation 1953 NA, is a rare-type asteroid from the middle region of the asteroid belt, approximately 15 kilometers in diameter. It was named after Robert T. A. Innes.

Discovery

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Innes was discovered on 13 July 1953, by South African astronomer Jacobus Bruwer at Johannesburg Observatory in South Africa.[10]

It was the first numbered discovery of astronomer Jacobus Bruwer. In addition, he also discovered the minor planets 1660 Wood, 1794 Finsen, and 3284 Niebuhr. The asteroid 1811 Bruwer was named in his honour by the Dutch, Dutch-American astronomer trio of the Palomar–Leiden survey.[11]

Orbit and classification

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It orbits the Sun in the central main-belt at a distance of 2.1–3.0 AU once every 4 years and 1 month (1,495 days). Its orbit has an eccentricity of 0.18 and an inclination of 9° with respect to the ecliptic.[1] Innes was first identified as 1940 GB at Turku Observatory in 1940, extending the body's observation arc by 13 years prior to its official discovery observation.[10]

Physical characteristics

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In the Tholen taxonomy, Innes has an AS-spectral type, an intermediate form of the rare A-types to the common stony asteroids (also see category listing).[12]

Rotation period

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In May 2005, astronomers Robert Stephens at the Center for Solar System Studies, California, and Lorenzo Franco at Balzaretto Observatory, near Rome, each obtained a rotational lightcurve of Innes. The photometric observations gave an identical rotation period of 3.191±0.001 hours with a brightness variation of 0.22 and 0.25 magnitude, respectively (U=3/3).[7][8]

Diameter and albedo

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According to the 2014-revised survey result of NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Innes measures 13.35 kilometers in diameter and its surface has an albedo of 0.248,[3] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 14.76 kilometers with an absolute magnitude of 11.52.[6]

Naming

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This minor planet was named for Scottish–South African astronomer Robert T. A. Innes (1861–1933), first director of the discovering Union Observatory from 1903 to 1927 (originally named Transvaal Observatory). He was a skilled observational astronomer, famous for his deliberate search for and discovery of the nearest star, Proxima Centauri, in 1915. He also made important theoretical and computational contributions to celestial mechanics and to the irregular rotation of the Earth. The astronomer is also honored by the lunar crater Innes.[2] The official naming citation was published by the Minor Planet Center on 1 July 1972 (M.P.C. 3297).[13]

References

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  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1658 Innes (1953 NA)" (2017-05-04 last obs.). Jet Propulsion Laboratory. Retrieved 30 June 2017.
  2. ^ a b Schmadel, Lutz D. (2007). "(1658) Innes". Dictionary of Minor Planet Names – (1658) Innes. Springer Berlin Heidelberg. p. 132. doi:10.1007/978-3-540-29925-7_1659. ISBN 978-3-540-00238-3.
  3. ^ 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 23 December 2016.
  4. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 23 December 2016.
  5. ^ a b c 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 e "LCDB Data for (1658) Innes". Asteroid Lightcurve Database (LCDB). Retrieved 23 December 2016.
  7. ^ a b Franco, Lorenzo; Papini, Riccardo (October 2014). "Rotational Period for 1658 Innes, (10597) 1995 TR10, and 30017 Shaundatta". The Minor Planet Bulletin. 41 (4): 243–244. Bibcode:2014MPBu...41..243F. ISSN 1052-8091. Retrieved 23 December 2016.
  8. ^ a b Stephens, Robert D. (October 2014). "Asteroids Observed from CS3: 2014 April-June". The Minor Planet Bulletin. 41 (4): 226–230. Bibcode:2014MPBu...41..226S. ISSN 1052-8091. Retrieved 23 December 2016.
  9. ^ 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 23 December 2016.
  10. ^ a b "1658 Innes (1953 NA)". Minor Planet Center. Retrieved 23 December 2016.
  11. ^ Schmadel, Lutz D. (2007). "(1811) Bruwer". Dictionary of Minor Planet Names – (1811) Bruwer. Springer Berlin Heidelberg. p. 145. doi:10.1007/978-3-540-29925-7_1812. ISBN 978-3-540-00238-3.
  12. ^ "JPL Small-Body Database Search Engine: spec. type = A (SMASSII)". JPL Solar System Dynamics. Retrieved 23 December 2016.
  13. ^ 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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