9423 Abt

9423 Abt
Discovery [1]
Discovered bySpacewatch
Discovery siteKitt Peak Obs.
Discovery date12 January 1996
(9423) Abt
Named after
Helmut Abt
(American astrophysicist)[2]
1996 AT7 · 1974 DU
1981 US15 · 1983 CK8
1990 VH15 · 1992 DP2
main-belt · (middle)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc42.95 yr (15,686 days)
Aphelion2.9681 AU
Perihelion2.4182 AU
2.6932 AU
4.42 yr (1,614 days)
0° 13m 22.8s / day
Physical characteristics
Dimensions12.690±0.145 km[4][5]
12.84±0.86 km[6]
13.29 km (calculated)[3]
3.2766±0.0003 h[7]
3.281±0.005 h[8]
0.10 (assumed)[3]
12.5[1][3] · 12.20[6] · 12.3[4] · 12.516±0.003 (R)[7] · 12.15±0.31[9]

9423 Abt, provisional designation 1996 AT7, is a stony background asteroid from the central region of the asteroid belt, approximately 13 kilometers in diameter. It was discovered on 12 January 1996, by the Spacewatch project of the University of Arizona at Kitt Peak National Observatory, United States.[10] The asteroid was named after American astronomer Helmut Abt.

Orbit and classification[]

Abt is a non-family asteroid from the main belt's background population. It orbits the Sun in the central main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,614 days). Its orbit has an eccentricity of 0.10 and an inclination of 9° with respect to the ecliptic.[1] It was first identified as 1974 DU at Crimea-Nauchnij in February 1974, extending the body's observation arc by 22 years prior to its official discovery observation at Kitt Peak.[10]


This minor planet was named after American astrophysicist Helmut Abt (born 1925), one of the founders of the discovering Kitt Peak National Observatory, after which the minor planet 2322 Kitt Peak is named. His research included stellar properties and systems. As senior or of The Astrophysical Journal he was responsible for converting it into its digital format.[2] The official naming citation was published by the Minor Planet Center on 11 November 2000 (M.P.C. 41568).[11]

Physical characteristics[]

Rotation period[]

In 2006, a rotational lightcurve of Abt was obtained from photometric observation at Hunters Hill Observatory, Australia. Lightcurve analysis gave a well-defined rotation period of 3.281 hours with a brightness variation of 0.30 magnitude (U=3).[8]

In 2012, a second lightcurve from the Palomar Transient Factory, California, gave a concurring period of 3.2766 hours with an amplitude of 0.33 magnitude (U=2).[7]

Diameter and albedo[]

According to the surveys carried out by the NEOWISE mission of the NASA's Wide-field Infrared Survey Explorer and the Japanese Akari satellite, Abt measures 12.690 and 12.84 kilometers in diameter, and its surface has an albedo of 0.132 and 0.141, respectively.[4][5][6]

The Collaborative Asteroid Lightcurve Link calculates a diameter of 13.29 kilometers, assuming an albedo of 0.10, a compromise figure between the brighter stony and darker carbonaceous bodies from the inner and outer asteroid-belt, respectively.[3]


  1. ^ a b c d "JPL Small-Body Database Browser: 9423 Abt (1996 AT7)" (2017-01-27 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b Schmadel, Lutz D. (2007). "(9423) Abt". Dictionary of Minor Planet Names – (9423) Abt. Springer Berlin Heidelberg. p. 692. doi:10.1007/978-3-540-29925-7_7509. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (9423) Abt". Asteroid Lightcurve Database (LCDB). Retrieved 27 April 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. Retrieved 27 April 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. Retrieved 4 December 2016.
  6. ^ 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. (online, AcuA catalog p. 153)
  7. ^ 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. Retrieved 27 April 2016.
  8. ^ a b Higgins, David; Pravec, Petr; Kusnirak, Peter; Galad, Adrian; Kornos, Leos; Pray, Donald; et al. (December 2006). "Asteroid lightcurve analysis at Hunters Hill Observatory and collaborating stations – autumn 2006". The Minor Planet Bulletin. 33 (4): 89–91. Bibcode:2006MPBu...33...89H. ISSN 1052-8091. Retrieved 12 January 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 27 April 2016.
  10. ^ a b "9423 Abt (1996 AT7)". Minor Planet Center. Retrieved 27 April 2016.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 April 2016.

External links[]