1127 Mimi, provisional designation 1929 AJ, is a dark background asteroid from the central regions of the asteroid belt, approximately 47 kilometers in diameter. It was discovered on 13 January 1929, by Belgian astronomer Sylvain Arend at the Royal Observatory of Belgium in Uccle.[14] Through a glitch in the naming process, the asteroid received the name "Mimi" instead of "Robelmonte" as originally intended by the discoverer.[2]

1127 Mimi
Discovery [1]
Discovered byS. Arend
Discovery siteUccle Obs.
Discovery date13 January 1929
MPC designation(1127) Mimi
Named after
"Mimi" Delporte
(wife of Eugène Delporte)[2]
1929 AJ · 1948 PU
A906 OA
main-belt · (middle)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.10 yr (31,812 days)
Aphelion3.2821 AU
Perihelion1.9104 AU
2.5962 AU
4.18 yr (1,528 days)
0° 14m 8.16s / day
Physical characteristics
Dimensions46.006±0.305 km[3]
46.18±10.10 km[4]
46.84±4.9 km[5][6]
48.198±0.465 km[7]
49.53±0.67 km[8]
50.67±13.81 km[9]
8.5410±0.0004 h[10]
8.541±0.1 h[11]
12.74557 h[12]
12.749±0.003 h[13]
Tholen = CX [1][6] · P[7]
B–V = 0.700 [1]
U–B = 0.300 [1]
10.77[4] · 10.95[1][5][6][7][8][9]

Orbit and classificationEdit

Mimi is a background asteroid with no assigned asteroid family. It orbits the Sun in the central main-belt at a distance of 1.9–3.3 AU once every 4 years and 2 months (1,528 days). Its orbit has an eccentricity of 0.26 and an inclination of 15° with respect to the ecliptic.[1]

The asteroid was first identified as A906 OA at Heidelberg Observatory in July 1906. The body's observation arc begins at Uccle in May 1934, more than 5 years after its official discovery observation.[14]

Physical characteristicsEdit

Mimi has been characterized as a dark P-type asteroid by the Wide-field Infrared Survey Explorer (WISE). In the Tholen classification, no unambiguous type could by assigned. Numerical color analysis showed that it is closest to the C-type asteroids and somewhat similar to the X-type asteroids (CX).[1]

Rotation period and poleEdit

In January 2004, the best-rated rotational lightcurve of Mimi was obtained from photometric observations by astronomer John Menke at his Menke Observatory in Barnesville, Maryland (no obs. code). Lightcurve analysis gave a well-defined rotation period of 12.749 hours with a brightness amplitude of 0.72 magnitude (U=3).[13] Two other lightcurves gave a shorter period of 8.541 hours with an amplitude of 0.93 and 0.95 magnitude, respectively (U=2/2).[10][11]

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 12.74557 hours, as well as a spin axis of (224.0°, −57.0°) in ecliptic coordinates (λ, β).[12]

Diameter and albedoEdit

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Mimi measures between 46.006 and 50.67 kilometers in diameter and its surface has an albedo between 0.031 and 0.04.[3][4][5][7][8][9]

The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.0336 and a diameter of 46.84 kilometers based on an absolute magnitude of 10.95.[6]


This minor planet was named after "Mimi" the wife of Belgian astronomer Eugène Delporte. Through an error, the names intended for 1127 Mimi (wife of Delporte) and 1145 Robelmonte (birthplace of Arend) had been switched, and each name had been proposed by the discoverer of the other asteroid. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 105).[2]


  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1127 Mimi (1929 AJ)" (2017-07-03 last obs.). Jet Propulsion Laboratory. Retrieved 31 August 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1127) Mimi". Dictionary of Minor Planet Names – (1127) Mimi. Springer Berlin Heidelberg. p. 96. doi:10.1007/978-3-540-29925-7_1128. ISBN 978-3-540-00238-3.
  3. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 31 August 2017.
  4. ^ a b c d 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 31 August 2017.
  5. ^ 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.
  6. ^ a b c d e "LCDB Data for (1127) Mimi". Asteroid Lightcurve Database (LCDB). Retrieved 31 August 2017.
  7. ^ a b c d e 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.
  8. ^ 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 17 October 2019. (online, AcuA catalog p. 153)
  9. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 31 August 2017.
  10. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1127) Mimi". Geneva Observatory. Retrieved 31 August 2017.
  11. ^ a b Maleszewski, Chester; Clark, Maurice (December 2004). "Bucknell University Observatory lightcurve results for 2003-2004". The Minor Planet Bulletin. 31 (4): 93–94. Bibcode:2004MPBu...31...93M. ISSN 1052-8091. Retrieved 31 August 2017.
  12. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 31 August 2017.
  13. ^ a b Menke, John L. (September 2005). "Lightcurves and periods for asteroids 471 Papagena, 675 Ludmilla, 1016 Anitra, 1127 Mimi, 1165 Imprinetta, 1171 Rustahawelia, and 2283 Bunke". The Minor Planet Bulletin. 32 (3): 64–66. Bibcode:2005MPBu...32...64M. ISSN 1052-8091. Retrieved 31 August 2017.
  14. ^ a b "1127 Mimi (1929 AJ)". Minor Planet Center. Retrieved 31 August 2017.

External linksEdit