20898 Fountainhills

20898 Fountainhills, provisional designation 2000 WE147, is a dark asteroid in a cometary orbit (ACO) from the outermost regions of the asteroid belt, approximately 37 kilometers (23 miles) in diameter. It was discovered on 30 November 2000, by American amateur astronomer Charles W. Juels at the Fountain Hills Observatory in Arizona, United States.[1] The D-type asteroid has a rotation period of 12.84 hours.[3] It was named for the city of Fountain Hills, Arizona, in the United States.[1]

20898 Fountainhills
Discovery [1]
Discovered byC. W. Juels
Discovery siteFountain Hills Obs.
Discovery date30 November 2000
MPC designation(20898) Fountainhills
Named after
Fountain Hills[1]
(U.S. city in Arizona)
2000 WE147 · 1975 BE
1994 NA1
main-belt[1][2] · (outer)[2][3]
background[4] · ACO [5]:872
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc66.49 yr (24,285 d)
Aphelion6.1881 AU
Perihelion2.2572 AU
4.2226 AU
8.68 yr (3,169 d)
0° 6m 48.96s / day
Jupiter MOID0.5295 AU
Physical characteristics
Mean diameter
37.08 km (derived)[3]
37.31±1.1 km[6]
41.53±0.85 km[7]
12.84±0.03 h[8]
0.0200 (derived)[3]
B–V = 0.767±0.008[9]
V–R = 0.428±0.010[9]
V–I = 0.826±0.008[9]
11.0[6] · 11.10[2][7]

Orbit and classificationEdit

Fountainhills is a non-family from the main belt's background population.[4] For an object in the asteroid belt, its orbit is extremely eccentric and highly inclined. With a Jupiter tisserand (TJupiter) of less than 3 and with no observable coma, it is an asteroid in cometary orbit (ACO) and a candidate for being a dormant or extinct comet.[5] It is however, not a damocloid based on current orbital criteria, which typically have a TJupiter of less than 2 (also see List of damocloids).

The asteroid orbits the Sun in the outer main-belt at a distance of 2.3–6.2 AU once every 8 years and 8 months (3,169 days; semi-major axis of 4.22 AU). Its orbit has an eccentricity of 0.47 and an inclination of 46° with respect to the ecliptic.[2] The body's observation arc begins with a precovery taken at Palomar Observatory during the Digitized Sky Survey in July 1951, more than 49 years prior to its official discovery observation at Fountain Hills.[1]

Fountainhills is the second most eccentric object as large as it is inside the orbit of Jupiter (after 1036 Ganymed), and the most highly inclined object of its size within the orbit of Jupiter. While its aphelion is outside that of Jupiter's orbit, it is so highly inclined that its furthest point from the Sun is far out of the ecliptic.[citation needed]

Physical characteristicsEdit

Fountainhills has been characterized as a dark D-type asteroid in a study of asteroids in cometary orbits using the Nordic Optical Telescope at Roque de los Muchachos Observatory on the Canary Island, Spain.[5]

Rotation periodEdit

In January 2001, a rotational lightcurve of Fountainhills was obtained from photometric observations by American amateur astronomer Bill Holliday at River Oaks Observatory (915) in Texas. Lightcurve analysis gave a well-defined rotation period of 12.84 hours with a brightness amplitude of 0.20 magnitude (U=3).[8]

Diameter and albedoEdit

According to the survey carried out by the Infrared Astronomical Satellite IRAS, and on data obtained by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Fountainhills measures between 37.31 and 41.53 kilometers in diameter and its surface has an albedo between 0.037 and 0.0505.[6][7] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.02 and a diameter of 37.08 kilometers based on an absolute magnitude of 12.02.[3]


This minor planet was named after the town of Fountain Hills, located near the Sonoran desert on the foothills of the McDowell Mountains, home to one of the world's tallest water fountains. The official naming citation was published by the Minor Planet Center on 9 May 2001 (M.P.C. 42678).[10]


  1. ^ a b c d e f "20898 Fountainhills (2000 WE147)". Minor Planet Center. Retrieved 10 April 2018.
  2. ^ a b c d e "JPL Small-Body Database Browser: 20898 Fountainhills (2000 WE147)" (2018-01-24 last obs.). Jet Propulsion Laboratory. Retrieved 10 April 2018.
  3. ^ a b c d e f g "LCDB Data for (20898) Fountainhills". Asteroid Lightcurve Database (LCDB). Retrieved 8 December 2017.
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 8 December 2017.
  5. ^ a b c d Licandro, J.; Alvarez-Candal, A.; de León, J.; Pinilla-Alonso, N.; Lazzaro, D.; Campins, H. (April 2008). "Spectral properties of asteroids in cometary orbits" (PDF). Astronomy and Astrophysics. 481 (3): 861–877. Bibcode:2008A&A...481..861L. doi:10.1051/0004-6361:20078340. Retrieved 8 December 2017.
  6. ^ 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. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  7. ^ a b c d Licandro, J.; Alí-Lagoa, V.; Tancredi, G.; Fernández, Y. (January 2016). "Size and albedo distributions of asteroids in cometary orbits using WISE data" (PDF). Astronomy and Astrophysics. 585: 12. arXiv:1510.02282. Bibcode:2016A&A...585A...9L. doi:10.1051/0004-6361/201526866. Retrieved 10 April 2018.
  8. ^ a b c Holliday, B. (June 2001). "Photometry of Asteroid 251 Sophia, 393 Lampetia, and (20898) 2000 WE147, September 2000 through January 2001". The Minor Planet Bulletin. 28: 26–28. Bibcode:2001MPBu...28...26H. Retrieved 8 December 2017.
  9. ^ a b c Ye, Q.-z. (February 2011). "BVRI Photometry of 53 Unusual Asteroids" (PDF). The Astronomical Journal. 141 (2): 8. arXiv:1011.0133. Bibcode:2011AJ....141...32Y. doi:10.1088/0004-6256/141/2/32. Retrieved 10 April 2018.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 10 April 2018.

External linksEdit