1023 Thomana

1023 Thomana
001023-asteroid shape model (1023) Thomana.png
Shape model of Thomana from its lightcurve
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date25 June 1924
(1023) Thomana
Named after
St. Thomas Choir of Leipzig
(German boys' choir)[2]
1924 RU · 1936 RG
main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc92.86 yr (33,916 days)
Aphelion3.4893 AU
Perihelion2.8442 AU
3.1667 AU
5.64 yr (2,058 days)
0° 10m 29.64s / day
Physical characteristics
Dimensions53.28±20.25 km[4]
58.27±1.6 km (IRAS:11)[5]
61.02±1.00 km[6]
61.34±4.17 km[7]
17.56±0.05 h[8]
17.56±0.01 h[9]
17.561±0.007 h[8]
17.5611±0.0005 h[10]
0.0649±0.004 (IRAS:11)[5]
Tholen = G[1] · G[3]
B–V = 0.764[1]
U–B = 0.493[1]
9.76[1][3][5][6][7] · 9.99[4] · 10.26±0.57[11]

1023 Thomana, provisional designation 1924 RU, is a rare-type carbonaceous background asteroid from the outer regions of the asteroid belt, approximately 58 kilometers in diameter. It was discovered on 25 June 1924, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany. The asteroid was named after the St. Thomas Choir of Leipzig.[12]

Classification and orbit[]

Thomana orbits the Sun in the outer main-belt at a distance of 2.8–3.5 AU once every 5 years and 8 months (2,058 days). Its orbit has an eccentricity of 0.10 and an inclination of 10° with respect to the ecliptic.[1] The asteroid's observation arc begins at Heidelberg, one night after its official discovery observation.[12]

Physical characteristics[]

In the Tholen classification, Thomana is an uncommon carbonaceous G-type asteroid.[1]

Rotation period[]

Between 2006 and 2009, three rotational lightcurves of Thomana were obtained from photometric observations by astronomers James W. Brinsfield, Pierre Antonini as well as René Roy and Laurent Bernasconi. Lightcurve analysis gave a concurring rotation period of 17.56 hours with a brightness variation between 0.27 and 0.36 magnitude (U=2/2/3-).[8][9]

Spin axis[]

In 2016, an international study modeled a lightcurve from various data sources with a period of 17.5611 hours and found two spin axis of (86.0°, −65.0°) and (272.0°, −42.0°), respectively, in ecliptic coordinates (λ, β) (Q=n.a.).[10]

Diameter and albedo[]

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Thomana measures between 53.28 and 61.34 kilometers in diameter and its surface has an albedo between 0.05 and 0.065.[4][5][6][7] The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is an albedo of 0.0649 and a diameter of 58.27 kilometers based on an absolute magnitude of 9.76.[3]


This minor planet was named by the discoverer after the St. Thomas Choir of Leipzig ("Thomanerchor"), a boys' choir at St. Thomas Church in Leipzig, Germany, where Johann Sebastian Bach used to work as music director. The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955 (H 98; LDS).[2]


  1. ^ a b c d e f g h "JPL Small-Body Database Browser: 1023 Thomana (1924 RU)" (2017-05-04 last obs.). Jet Propulsion Laboratory. Retrieved 3 August 2017.
  2. ^ a b Schmadel, Lutz D. (2007). "(1023) Thomana". Dictionary of Minor Planet Names – (1023) Thomana. Springer Berlin Heidelberg. p. 88. doi:10.1007/978-3-540-29925-7_1024. ISBN 978-3-540-00238-3.
  3. ^ a b c d "LCDB Data for (1023) Thomana". Asteroid Lightcurve Database (LCDB). Retrieved 3 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 3 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 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. (online, AcuA catalog p. 153)
  7. ^ 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:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 3 August 2017.
  8. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (1023) Thomana". Geneva Observatory. Retrieved 3 August 2017.
  9. ^ a b Brinsfield, James W. (April 2010). "Asteroid Lightcurve Analysis at Via Capote Observatory: 4th Quarter 2009". The Minor Planet Bulletin. 37 (2): 50–53. Bibcode:2010MPBu...37...50B. ISSN 1052-8091. Retrieved 3 August 2017.
  10. ^ a b Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. arXiv:1510.07422. Bibcode:2016A&A...586A.108H. doi:10.1051/0004-6361/201527441.
  11. ^ 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:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 3 August 2017.
  12. ^ a b "1023 Thomana (1924 RU)". Minor Planet Center. Retrieved 3 August 2017.

External links[]