1384 Kniertje

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1384 Kniertje
Discovery [1]
Discovered byH. van Gent
Discovery siteJohannesburg Obs.
Discovery date9 September 1934
MPC designation(1384) Kniertje
Named after
Kniertje [2] (fictional character)
1934 RX
main-belt · (middle)
Eunomia[3] · Adeona[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc83.06 yr (30,338 days)
Aphelion3.1649 AU
Perihelion2.1872 AU
2.6760 AU
4.38 yr (1,599 days)
0° 13m 30.36s / day
Physical characteristics
Dimensions21.52±6.01 km[5]
21.72±6.93 km[6]
26.14±0.56 km[7]
26.29±0.38 km[8]
26.517±0.090 km[9]
26.59 km (derived)[3]
27.51±1.6 km[10]
29.592±0.230 km[11]
9.78±0.02 h[12]
9.807±0.002 h[12]
9.808±0.001 h[12]
9.824±0.001 h[13]
9.872±0.012 h[14]
12.255±0.004 h[15][a]
0.0701 (derived)[3]
S (assumed, Eunomia)[3]
C (assumed; Adeona)[16]:23
9.70[10] · 11.38[3][11] · 11.4[17] · 11.50[7][8] · 11.60[1][6] · 11.64[5] · 11.81±0.22[18]

1384 Kniertje, provisional designation 1934 RX, is a dark Adeonian asteroid from the central regions of the asteroid belt, approximately 26 kilometers in diameter. It was discovered on 9 September 1934, by Dutch astronomer Hendrik van Gent at the Union Observatory in Johannesburg, South Africa.[19] The asteroid was named after a character in the Dutch play Op Hoop van Zegen by Herman Heijermans.[2]

Orbit and classification[edit]

Kniertje is a member of the Adeona family (505),[4] a large family of carbonaceous asteroids in the central main belt, named after 145 Adeona. It is also dynamically classified as a member of the Eunomia family (502), the largest in the intermediate main belt with more than 5,000 stony asteroids.[3][16]:23

The asteroid orbits the Sun in the central asteroid belt at a distance of 2.2–3.2 AU once every 4 years and 5 months (1,599 days). Its orbit has an eccentricity of 0.18 and an inclination of 12° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Johannesburg in 1934.[19]

Physical characteristics[edit]

Kniertje's spectral type is unknown. Although the LCDB assumes an S-type (due to its dynamical classification to the stony Eunomia family), a low albedo of 0.0701 is derived (see below) which is typical for carbonaceous C-type asteroids and in agreement with the overall spectral type of the Adeona family (505).[3][16]:23

Rotation period[edit]

Several rotational lightcurves of Kniertje have been obtained from photometric observations since 2003. Lightcurve analysis gave a rotation period between 9.78 and 9.872 hours with a brightness variation between 0.15 and 0.32 magnitude (U=2/2/2/2/2).[12][13][14] An alternative period solution of 12.255 hours with an amplitude of 0.33 magnitude was found by Brian Warner in March 2006 (U=2).[15][a]

Diameter and albedo[edit]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Kniertje measures between 21.52 and 29.592 kilometers in diameter and its surface has an albedo between 0.0351 and 0.3077.[5][6][7][8][9][10][11]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0701 and a diameter of 26.59 kilometers based on an absolute magnitude of 11.38.[3]


This minor planet was named after the principal character in Op Hoop van Zegen, a play by Dutch writer Herman Heijermans (1864–1924). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 125).[2]


  1. ^ a b Lightcurve plot of 1384 Kniertje, Palmer Divide Observatory, Brian D. Warner (2006). Observer's comment: "a period of 9.816 h cannot be formally excluded". Summary figures at LCDB.


  1. ^ a b c d "JPL Small-Body Database Browser: 1384 Kniertje (1934 RX)" (2017-10-01 last obs.). Jet Propulsion Laboratory. Retrieved 27 October 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1384) Kniertje". Dictionary of Minor Planet Names – (1384) Kniertje. Springer Berlin Heidelberg. p. 112. doi:10.1007/978-3-540-29925-7_1385. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g h "LCDB Data for (1384) Kniertje". Asteroid Lightcurve Database (LCDB). Retrieved 27 October 2017.
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 27 October 2017.
  5. ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv:1606.08923. Bibcode:2016AJ....152...63N. doi:10.3847/0004-6256/152/3/63. Retrieved 27 October 2017.
  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 27 October 2017.
  7. ^ a b c d 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 27 October 2017.
  8. ^ a b c d 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 27 October 2017.
  9. ^ a b 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 27 October 2017.
  10. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Archived from the original on 2016-06-03. Retrieved 27 October 2017.
  11. ^ 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.
  12. ^ a b c d Behrend, Raoul. "Asteroids and comets rotation curves – (1384) Kniertje". Geneva Observatory. Retrieved 27 October 2017.
  13. ^ a b Hawkins, Scot; Ditteon, Richard (March 2008). "Asteroid Lightcurve Analysis at the Oakley Observatory - May 2007". The Minor Planet Bulletin. 35 (1): 1–4. Bibcode:2008MPBu...35....1H. ISSN 1052-8091. Retrieved 27 October 2017.
  14. ^ a b Vinson, Rachel; Moore, Robert; Ditteon, Richard (July 2014). "Asteroid Lightcurve Analysis at the Oakley Southern Sky Observatory: 2013 October". The Minor Planet Bulletin. 41 (3): 169–170. Bibcode:2014MPBu...41..169V. ISSN 1052-8091. Retrieved 27 October 2017.
  15. ^ a b Warner, Brian D. (December 2006). "Asteroid lightcurve analysis at the Palmer Divide Observatory - March - June 2006". The Minor Planet Bulletin. 33 (4): 85–88. Bibcode:2006MPBu...33...85W. ISSN 1052-8091. Retrieved 27 October 2017.
  16. ^ a b c Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.
  17. ^ Faure, Gerard; Garret, Lawrence (December 2007). "Suggested Revised H Values of Selected Asteroids: Report Number 3". The Minor Planet Bulletin. 34 (4): 95–99. Bibcode:2007MPBu...34...95F. ISSN 1052-8091. Retrieved 27 October 2017.
  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 27 October 2017.
  19. ^ a b "1384 Kniertje (1934 RX)". Minor Planet Center. Retrieved 27 October 2017.

External links[edit]