1155 Aënna

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1155 Aënna
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 26 January 1928
MPC designation (1155) Aenna
Named after
Astronomische Nachrichten
(Astronomy journal)[2]
1928 BD · 1928 FU
1941 UZ · 1982 DR6
main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 89.44 yr (32,668 days)
Aphelion 2.8697 AU
Perihelion 2.0586 AU
2.4641 AU
Eccentricity 0.1646
3.87 yr (1,413 days)
0° 15m 17.28s / day
Inclination 6.5935°
Physical characteristics
Dimensions 9.284±0.524 km[4]
11.36 km (derived)[3]
11.70±0.75 km[5]
14.093±0.105 km[6]
8.07±0.04 h[7]
0.2169 (derived)[3]
SMASS = Xe [1] · X[3]
11.5[5][6] · 11.90[4] · 12.0[1][3] · 12.41±0.79[8]

1155 Aënna, provisional designation 1928 BD, is an asteroid from the inner regions of the asteroid belt, approximately 11 kilometers in diameter. It was discovered on 26 January 1928, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.[9] It is named for the astronomy journal Astronomische Nachrichten.[2]

Orbit and classification[edit]

In the SMASS taxonomy, the X-type asteroid is classified as a Xe-type, an intermediary that transitions to the bright E-type asteroids. The spectra of a Xe-type contains an absorption feature near 0.49 μm, which is thought to be related with the presence of the iron sulfide mineral troilite, typically found in lunar and Martian meteorites.[10] Aënna orbits the Sun in the inner main-belt at a distance of 2.1–2.9 AU once every 3 years and 10 months (1,413 days). Its orbit has an eccentricity of 0.16 and an inclination of 7° with respect to the ecliptic.[1] The body's observation arc begins at Heidelberg with its official discovery observation in 1928.[9]

Physical characteristics[edit]

Rotation period[edit]

French amateur astronomer René Roy obtained a rotational lightcurve of Aënna from photometric observations taken in December 2015. Lightcurve analysis gave a rotation period of 8.07 hours with a brightness variation of 0.28 magnitude (U=2+).[7]

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Aënna measures between 9.28 and 14.09 kilometers in diameter, and its surface has an albedo between 0.225 and 0.356.[4][5][6] The Collaborative Asteroid Lightcurve Link agrees best with Akari, and derives an albedo of 0.2169 with a diameter of 11.36 kilometers and an absolute magnitude of 12.0.[3]


This minor planet was named after Astronomische Nachrichten, one of the first international journals in the field of astronomy. The constructed name "Aënna" contains the German pronunciation of the initials "A" and "N" followed by the mandatory feminine ending used for asteroids. The naming was proposed by the Astronomisches Rechen-Institut and mentioned in The Names of the Minor Planets by Paul Herget in 1955 (108).[2]


  1. ^ a b c d e "JPL Small-Body Database Browser: 1155 Aenna (1928 BD)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 26 July 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1155) Aënna. Springer Berlin Heidelberg. p. 97. ISBN 978-3-540-00238-3. Retrieved 7 February 2017. 
  3. ^ a b c d e f "LCDB Data for (1155) Aënna". Asteroid Lightcurve Database (LCDB). Retrieved 7 February 2017. 
  4. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. arXiv:1209.5794Freely accessible. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 7 February 2017. 
  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 7 February 2017. 
  6. ^ 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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 7 February 2017. 
  7. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1155) Aënna". Geneva Observatory. Retrieved 7 February 2017. 
  8. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 7 February 2017. 
  9. ^ a b "1155 Aënna (1928 BD)". Minor Planet Center. Retrieved 7 February 2017. 
  10. ^ Bus, Schelte J.; Binzel, Richard P. (July 2002). "Phase II of the Small Main-Belt Asteroid Spectroscopic Survey. A Feature-Based Taxonomy". Icarus. 158 (1): 146–177. Bibcode:2002Icar..158..146B. doi:10.1006/icar.2002.6856. Retrieved 7 February 2017. 

External links[edit]