4222 Nancita

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4222 Nancita
Discovery [1]
Discovered by E. Helin
Discovery site Palomar Obs.
Discovery date 13 March 1988
MPC designation (4222) Nancita
Named after
Nancy Coker Helin
(discoverer's family)[2]
1988 EK1 · 1950 TF4
1952 HN · 1968 QL1
1972 XQ1 · 1979 SL6
1983 XC1 · 1988 KL
main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 48.77 yr (17,813 days)
Aphelion 3.0666 AU
Perihelion 1.6705 AU
2.3685 AU
Eccentricity 0.2947
3.65 yr (1,331 days)
0° 16m 13.44s / day
Inclination 3.7412°
Physical characteristics
Dimensions 8.47±0.8 km (IRAS:11)[4]
9.14±0.71 km[5]
9.707±0.215 km[7]
3.8732±0.0003 h[8]
0.2703±0.061 (IRAS:11)[4]
SMASS = S[1] · S[3]
12.3[1] · 12.4[3][4][5][7]

4222 Nancita, provisional designation 1988 EK1, is an eccentric, stony asteroid and upcoming Mars-crosser from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 13 March 1988, by American astronomer Eleanor Helin at Palomar Observatory in California, United States.[9] It was named after the discoverer's daughter-in-law, Nancy Coker Helin.

Orbit and classification[edit]

Nancita will become a Mars-crossing asteroid in June 2019. It orbits the Sun in the inner main-belt at a distance of 1.7–3.1 AU once every 3 years and 8 months (1,331 days). Its orbit has an eccentricity of 0.29 and an inclination of 4° with respect to the ecliptic.[1]

The asteroid was first identified as 1950 TF4 at McDonald Observatory in 1950. Its observation arc begins at Crimea–Nauchnij in 1968, when it was identified as 1968 QL1, 20 years prior to its official discovery observation at Palomar.[9]

Physical characteristics[edit]

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

Rotation and shape[edit]

A rotational lightcurve of Nancita, obtained at the Australian Hunters Hill Observatory (E14) and collaborating stations in 2006, gave a well-defined rotation period of 3.8732 hours with a high brightness amplitude of 0.97 in magnitude (U=3), indicating that the body has a non-spheroidal shape.[8]

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, Nancita measures between 8.5 and 9.7 kilometers in diameter and its surface has an albedo in the range of 0.21 to 0.27.[4][5][6][7] The Collaborative Asteroid Lightcurve Link agrees with the results obtained by IRAS.[3]


This minor planet was named in honor of Nancy Coker Helin, daughter-in-law of the discoverer, and wife to Bruce Helin, after whom the minor planet 2430 Bruce Helin had previously been named. Nancy is described by the discoverer as a talented singer, composer and teacher, who has brought music and joy to her family.[2] The official naming citation was published by the Minor Planet Center on 2 December 1990 (M.P.C. 17466).[10]


  1. ^ a b c d e f "JPL Small-Body Database Browser: 4222 Nancita (1988 EK1)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 20 June 2017. 
  2. ^ a b Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4222) Nancita. Springer Berlin Heidelberg. p. 361. ISBN 978-3-540-00238-3. Retrieved 2 May 2016. 
  3. ^ a b c d "LCDB Data for (4222) Nancita". Asteroid Lightcurve Database (LCDB). Retrieved 2 May 2016. 
  4. ^ 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. Bibcode:2004PDSS...12.....T. Retrieved 2 May 2016. 
  5. ^ 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 2 May 2016. 
  6. ^ 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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 5 December 2016. 
  7. ^ 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 2 May 2016. 
  8. ^ a b Higgins, David; Pravec, Petr; Kusnirak, Peter; Reddy, Vishnu; Dyvig, Ron (September 2006). "Asteroid lightcurve analysis at Hunters Hill Observatory and collaborating stations - summer 2005/6". The Minor Planet Bulletin. 33 (3): 64–66. Bibcode:2006MPBu...33...64H. ISSN 1052-8091. Retrieved 2 May 2016. 
  9. ^ a b "4222 Nancita (1988 EK1)". Minor Planet Center. Retrieved 2 May 2016. 
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 2 May 2016. 

External links[edit]