1543 Bourgeois

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1543 Bourgeois
Discovery [1]
Discovered by E. Delporte
Discovery site Uccle Obs.
Discovery date 21 September 1941
MPC designation (1543) Bourgeois
Named after
Paul Bourgeois[2]
(Belgian astronomer)
1941 SJ · A911 MF
main-belt · (middle)[3]
background [4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 75.81 yr (27,689 days)
Aphelion 3.4854 AU
Perihelion 1.7812 AU
2.6333 AU
Eccentricity 0.3236
4.27 yr (1,561 days)
0° 13m 50.52s / day
Inclination 11.021°
Physical characteristics
Dimensions 11.985±0.673 km[5]
16.73 km (calculated)[3]
2.48±0.01 h[6]
0.1 (assumed)[3]
S/C (assumed)[3]
11.90[5] · 12.0[1][3] · 12.06±0.18[7]

1543 Bourgeois, provisional designation 1941 SJ, is a stony asteroid from the central asteroid belt's background population, approximately 12 kilometers in diameter. It was discovered on 21 September 1941, by astronomer Eugène Delporte at the Royal Observatory of Belgium in Uccle.[8] The asteroid was named after Belgian astronomer Paul Bourgeois.[2]

Orbit and classification[edit]

Bourgeois is a non-family asteroid from the main belt's background population.[4] It orbits the Sun in the central asteroid belt at a distance of 1.8–3.5 AU once every 4 years and 3 months (1,561 days). Its orbit has an eccentricity of 0.32 and an inclination of 11° with respect to the ecliptic.[1]

The asteroid was first identified as A911 MF at Johannesburg Observatory in June 1911. The body's observation arc begins at Istanbul Observatory (080), eight days prior to its official discovery observation at Uccle.[8]

Physical characteristics[edit]

No spectral type has been determined. The Lightcurve Data Base considers Bourgeois equally likely to be of a stony or carbonaceous, while albedo measurements by Wide-field Infrared Survey Explorer suggest that it is a stony S-type asteroid (see below).[3]

Rotation period[edit]

In August 2005, a rotational lightcurve of Bourgeois was obtained from photometric observations by French amateur astronomer Laurent Bernasconi. Analysis of the fragmentary lightcurve gave a rotation period of 2.48 hours with a brightness amplitude of 0.03 magnitude (U=1).[6] As of 2017, no secure period has been obtained.[3]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's WISE telescope, Bourgeois measures 11.985 kilometers in diameter and its surface has an albedo of 0.214.[5] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.1 – a compromise albedo between the stony (0.20) and carbonaceous (0.057) types, used as a default for asteroids with a semi-major axis between 2.6 and 2.7 AU – and calculates a diameter of 16.73 kilometers based on an absolute magnitude of 12.0.[3]


This minor planet was named in memory of Paul Bourgeois (1898–1974), director of the discovering observatory at Uccle, professor at the Free University of Brussels, credited discoverer of asteroid 1547 Nele, author of various publications in astrometry, astrophysics, meridian astronomy and stellar statistics.[2] The official naming citation was published by the Minor Planet Center before November 1977 (M.P.C. 3930).[9]


  1. ^ a b c d "JPL Small-Body Database Browser: 1543 Bourgeois (1941 SJ)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 7 October 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1543) Bourgeois. Springer Berlin Heidelberg. p. 122. ISBN 978-3-540-00238-3. Retrieved 7 October 2017. 
  3. ^ a b c d e f g h "LCDB Data for (1543) Bourgeois". Asteroid Lightcurve Database (LCDB). Retrieved 7 October 2017. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 7 October 2017. 
  5. ^ 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 October 2017. 
  6. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1543) Bourgeois". Geneva Observatory. Retrieved 7 October 2017. 
  7. ^ 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 October 2017. 
  8. ^ a b "1543 Bourgeois (1941 SJ)". Minor Planet Center. Retrieved 7 October 2017. 
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 7 October 2017. 

External links[edit]