Open main menu

4435 Holt, provisional designation 1983 AG2, is a stony asteroid, sizable Mars-crosser and binary system from the inner regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 13 January 1983, by American astronomer Carolyn Shoemaker at the Palomar Observatory in California, United States.[3] It was later named after American astronomer Henry E. Holt.[2] The discovery of its companion was announced in January 2018.

4435 Holt
Discovery [1]
Discovered byC. Shoemaker
Discovery sitePalomar Obs.
Discovery date13 January 1983
MPC designation(4435) Holt
Named after
Henry E. Holt
(American astronomer)[2]
1983 AG2 · 1978 PZ2
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc37.89 yr (13,840 days)
Aphelion3.0939 AU
Perihelion1.5405 AU
2.3172 AU
3.53 yr (1,288 days)
0° 16m 45.84s / day
Known satellites1
Physical characteristics
Mean diameter
5.03±1.17 km[5]
6.44 km (derived)[4]
2.8670±0.0002 h[4]
0.20 (assumed)[4]
0.28±0.15 km[5]
SMASS = S[1][4]
13.1[1] · 13.32±0.11[6][7]

Orbit and classificationEdit

Holt orbits the Sun in the inner main-belt at a distance of 1.5–3.1 AU once every 3 years and 6 months (1,288 days). Its orbit has an eccentricity of 0.34 and an inclination of 22° with respect to the ecliptic.[1] The first precovery was taken at Crimea-Nauchnij in 1978, extending the asteroid's observation arc by 5 years prior to its discovery.[3]


This minor planet was named for American planetary geologist and astronomer Henry E. Holt (born 1929), at NAU and USGS, who has explored the surface of the Moon, its geology and photometric properties during the Apollo and Surveyor programs.[2]

After his retirement, Holt was a principal participant in the Palomar Asteroid and Comet Survey (PACS) from 1983 to 1993.[8] Holt has discovered and co-discovered six comets and 683 minor planets between 1989 and 1993,[9] including 4581 Asclepius,[10] a potentially hazardous asteroid that has made the closest approach to Earth of all numbered asteroids.[2] The official naming citation was published by the Minor Planet Center on 30 January 1991 (M.P.C. 17656).[11]

Physical characteristicsEdit

In the SMASS classification, Holt is a common S-type asteroid.[1]

Diameter and albedoEdit

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Holt measures 5.03 kilometers in diameter and its surface has an albedo of 0.28,[5] while the Collaborative Asteroid Lightcurve Linkassumes a standard albedo for stony asteroids of 0.20 and derives a diameter of 6.44 kilometer with an absolute magnitude of 13.32.[4][6][7]

Satellite and rotationEdit

In November 2017, a rotational lightcurve of Holt was obtained from photometric observation by Robert Stephens and collaborators. Lightcurve analysis gave a rotation period of 2.8670±0.0002 hours with a brightness variation of 0.15 magnitude..[4] During the observations, the presence of an approximately 2-kilometer sized minor-planet moon was detected. The satellite orbits its primary every 42.6 hours (1.777 d).


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 4435 Holt (1983 AG2)" (2016-06-29 last obs.). Jet Propulsion Laboratory. Retrieved 20 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(4435) Holt". Dictionary of Minor Planet Names – (4435) Holt. Springer Berlin Heidelberg. p. 381. doi:10.1007/978-3-540-29925-7_4384. ISBN 978-3-540-00238-3.
  3. ^ a b c "4435 Holt (1983 AG2)". Minor Planet Center. Retrieved 25 January 2016.
  4. ^ a b c d e f g "LCDB Data for (4435) Holt". Asteroid Lightcurve Database (LCDB). Retrieved 17 May 2016.
  5. ^ a b c 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 20 June 2017.
  6. ^ a b Wisniewski, W. Z.; Michalowski, T. M.; Harris, A. W.; McMillan, R. S. (March 1995). "Photoelectric Observations of 125 Asteroids". Abstracts of the Lunar and Planetary Science Conference. 26: 1511. Bibcode:1995LPI....26.1511W. Retrieved 17 May 2016.
  7. ^ a b Pravec, Petr; Harris, Alan W.; Kusnirák, Peter; Galád, Adrián; Hornoch, Kamil (September 2012). "Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations". Icarus. 221 (1): 365–387. Bibcode:2012Icar..221..365P. doi:10.1016/j.icarus.2012.07.026. Retrieved 17 May 2016.
  8. ^ Shoemaker, C. S.; Holt, H. E.; Shoemaker, E. M.; Bowell, E.; Levy, D. H. (December 1992). "The Palomar Asteroid and Comet Survey (PACS), 1983-1993". Abstracts for the IAU Symposium 160: Asteroids. 810: 269. Bibcode:1993LPICo.810..269S. Retrieved 25 January 2016.
  9. ^ "Minor Planet Discoverers (by number)". Minor Planet Center. 22 March 2016. Retrieved 26 April 2016.
  10. ^ "4581 Asclepius (1989 FC)". Minor Planet Center. Retrieved 26 April 2016.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 17 May 2016.

External linksEdit