4585 Ainonai

4585 Ainonai
Discovery [1]
Discovered byK. Endate
K. Watanabe
Discovery siteKitami Obs.
Discovery date16 May 1990
Designations
(4585) Ainonai
Named after
Ainonai, near Kitami
(Japanese town)[2]
1990 KQ · 1972 LU
1978 WL12 · 1981 LC
Orbital characteristics [3]
Epoch 31 May 2020 (JD 2459000.5)
Uncertainty parameter 0
Observation arc47.87 yr (17,486 d)
Aphelion3.3818 AU
Perihelion2.0894 AU
2.7356 AU
Eccentricity0.2362
4.52 yr (1,653 d)
220.84°
0° 13m 4.08s / day
Inclination10.549°
82.966°
184.23°
Physical characteristics
10.920±0.122 km[7]
38.31±0.05 h[8]
0.112±0.011[7]
C (family-based)[9][10]

4585 Ainonai (prov. designation: 1990 KQ) is a dark Chloris asteroid, approximately 11 kilometers (6.8 miles) in diameter, located in the central region of the asteroid belt. It was discovered on 16 May 1990, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at the Kitami Observatory in eastern Hokkaidō, Japan.[1] The presumed carbonaceous C-type asteroid has a longer than average rotation period of 38.3 hours. It was named for the Japanese town of Ainonai, located near the discovering observatory.[2]

Orbit and classification

When applying the hierarchical clustering method to its proper orbital elements, Ainonai is a core member of the Chloris family (509),[4][5][6] a smaller family of carbonaceous main-belt asteroids, named after its parent body 410 Chloris.[10] It orbits the Sun in the central asteroid belt at a distance of 2.1–3.4 AU once every 4 years and 6 months (1,653 days; semi-major axis of 2.74 AU). Its orbit has an eccentricity of 0.24 and an inclination of 11° with respect to the ecliptic.[3] The body's observation arc begins with its first observation as 1972 LU at Crimea–Nauchnij on 9 June 1972, or 18 years prior to its official discovery observation at Kitami.[1]

Naming

This minor planet was named after Ainonai, a small Japanese town located near Kitami in eastern Hokkaidō. Asteroids 3785 Kitami and 3720 Hokkaido are named after these two places.[2] The official naming citation was published by the Minor Planet Center on 21 November 1991 (M.P.C. 19338).[11]

Physical characteristics

Ainonai is an assumed carbonaceous C-type asteroid.[9] This agrees with the overall spectral type of the Chloris family.[10]: 23 

Lightcurve

In June 2008, a rotational lightcurve of Ainonai was obtained from photometric observations by James W. Brinsfield at the Via Capote Observatory (G69) in California. Lightcurve analysis gave a rotation period of (38.31±0.05) hours with a brightness variation of (0.30±0.02) magnitude (U=3–).[8]

Diameter and albedo

According to observations from the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Ainonai measures (10.920±0.122) kilometers in diameter and its surface has an albedo of (0.112±0.011).[7] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 14.64 kilometers based on an absolute magnitude of 12.9.[9]

References

  1. ^ a b c d e "4585 Ainonai (1990 KQ)". Minor Planet Center. Retrieved 11 June 2020.
  2. ^ a b c Schmadel, Lutz D. (2007). "(4585) Ainonai". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 395. doi:10.1007/978-3-540-29925-7_4515. ISBN 978-3-540-00238-3.
  3. ^ a b c d "JPL Small-Body Database Browser: 4585 Ainonai (1990 KQ)" (2020-04-24 last obs.). Jet Propulsion Laboratory. Retrieved 11 June 2020.
  4. ^ a b "Asteroid 4585 Ainonai – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 11 June 2020.
  5. ^ a b "Asteroid 4585 Ainonai – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 11 June 2020.
  6. ^ a b Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1997). "Asteroid Dynamical Families". NASA Planetary Data System: EAR-A-5-DDR-FAMILY-V4.1. Retrieved 11 June 2020.} (PDS main page)
  7. ^ a b c d Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System. Bibcode:2016PDSS..247.....M. Retrieved 11 June 2020.
  8. ^ a b Brinsfield, James W. (October 2008). "Asteroid Lightcurve Analysis at the Via Capote Observatory: 2nd Quarter 2008" (PDF). Minor Planet Bulletin. 35 (4): 179–181. Bibcode:2008MPBu...35..179B. ISSN 1052-8091. Archived from the original (PDF) on 17 March 2020. Retrieved 11 June 2020.
  9. ^ a b c "LCDB Data for (4585) Ainonai". Asteroid Lightcurve Database (LCDB). Retrieved 11 June 2020.
  10. ^ 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. S2CID 119280014.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 11 June 2020.