1112 Polonia

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1112 Polonia
Discovery [1]
Discovered by P. Shajn
Discovery site Simeiz Obs.
Discovery date 15 August 1928
MPC designation (1112) Polonia
Named after
(European country)[2]
1928 PE · 1933 PA
A908 XA
main-belt[1][3] · (outer)
Orbital characteristics[3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc 89.20 yr (32,582 d)
Aphelion 3.3423 AU
Perihelion 2.6963 AU
3.0193 AU
Eccentricity 0.1070
5.25 yr (1,916 d)
0° 11m 16.44s / day
Inclination 8.9911°
Physical characteristics
Mean diameter
35.76±1.6 km[6]
37.55±0.60 km[7]
39.661±0.334 km[8]
47.058±0.368 km[9]
82.5±0.5 h[10][a]
S (Tholen)[3]
L (SDSS-MOC)[11]
B–V = 0.797[3]
U–B = 0.447[3]

1112 Polonia, provisional designation 1928 PE, is an Eoan asteroid from the outer regions of the asteroid belt, approximately 38 kilometers (24 miles) in diameter. Discovered by Soviet astronomer Pelageya Shajn at Simeiz in 1928,[1] it was the first asteroid discovery made by a woman.[2] The L-type asteroid has a long rotation period of 82.5 hours,[5] and was named for the country of Poland.[2]


Polonia was first observed as A908 XA at the German Heidelberg Observatory in December 1908. It was officially discovered on 15 August 1928, by Soviet astronomer Pelageya Shajn at the Simeiz Observatory on the Crimean peninsula.[1] On the following night at Simeis, it was independently discovered by her college Grigory Neujmin.[2] The Minor Planet Center only recognized the first discoverer.[1]

Polonia was Shajn's first discovery; and the first asteroid discovery made by a woman,[2] bringing a long-standing tradition – which began with the discovery of 1 Ceres in 1801 – of more than a thousand minor planet discoveries exclusively made by male astronomers, to an end.

Orbit and classification[edit]

Polonia is a core member of the Eos family (606),[4][5] the largest asteroid family of the outer main belt consisting of nearly 10,000 asteroids.[12]

It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 3 months (1,916 days; semi-major axis of 3.02 AU). Its orbit has an eccentricity of 0.11 and an inclination of 9° with respect to the ecliptic.[3] The body's observation arc begins with its official discovery observation at Simeiz in 1928.[1]

Physical characteristics[edit]

In the Tholen classification, Polonia is a common, stony S-type asteroid.[3] In the more refined SDSS-based taxonomy, it is characterized as an uncommon L-type,[11] which is similar to a K-type, the overall spectral type of the Eoan asteroids.[12]:23

Rotation period[edit]

In October 2007, a rotational lightcurve of Polonia was obtained from photometric observations by American astronomer Brian Warner at his Palmer Divide Observatory in Colorado. Lightcurve analysis gave a long rotation period of 82.5 hours with a brightness amplitude of 0.20 magnitude (U=2).[5][10][a] The asteroid's long period it is close to that of a slow rotator.

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, Polonia measures between 35.76 and 47.058 kilometers in diameter and its surface has an albedo between 0.0763 and 0.1319.[6][7][8][9] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.1319 and a diameter of 35.76 kilometers based on an absolute magnitude of 10.05.[5]


This minor planet was named "Polonia", the Latin name for the European country of Poland. It is the first minor planet discovery made by a woman. The naming was proposed by L. Matkiewicz, an astronomer of Polish origin, who calculated the body's orbit. The official citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 104).[2]


  1. ^ a b Lightcurve plot of 1(1112) Polonia, Palmer Divide Observatory, B. D. Warner (2007). Rotation period 82.5±0.5 hours with a brightness amplitude of 0.20±0.03 mag. Quality code is 2. Summary figures at the LCDB.


  1. ^ a b c d e f "1112 Polonia (1928 PE)". Minor Planet Center. Retrieved 29 May 2018. 
  2. ^ a b c d e f Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1112) Polonia. Springer Berlin Heidelberg. p. 94. ISBN 978-3-540-00238-3. Retrieved 29 May 2018. 
  3. ^ a b c d e f g h "JPL Small-Body Database Browser: 1112 Polonia (1928 PE)" (2017-10-29 last obs.). Jet Propulsion Laboratory. Retrieved 29 May 2018. 
  4. ^ a b "Asteroid 1112 Polonia". Small Bodies Data Ferret. Retrieved 29 May 2018. 
  5. ^ a b c d e f "LCDB Data for (1112) Polonia". Asteroid Lightcurve Database (LCDB). Retrieved 29 May 2018. 
  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. Bibcode:2004PDSS...12.....T. Retrieved 29 May 2018. 
  7. ^ 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 29 May 2018.  Online catalog
  8. ^ 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" (PDF). The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645Freely accessible. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 29 May 2018. 
  9. ^ 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 29 May 2018.  (catalog)
  10. ^ a b Warner, Brian D. (June 2008). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: September-December 2007". The Minor Planet Bulletin. 35 (2): 67–71. Bibcode:2008MPBu...35...67W. ISSN 1052-8091. Retrieved 29 May 2018. 
  11. ^ a b Carvano, J. M.; Hasselmann, P. H.; Lazzaro, D.; Mothé-Diniz, T. (February 2010). "SDSS-based taxonomic classification and orbital distribution of main belt asteroids". Astronomy and Astrophysics. 510: 12. Bibcode:2010A&A...510A..43C. doi:10.1051/0004-6361/200913322. Retrieved 29 May 2018. 
  12. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families" (PDF). Asteroids IV: 297–321. arXiv:1502.01628Freely accessible. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. Retrieved 29 May 2018. 

External links[edit]