1161 Thessalia

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
1161 Thessalia
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 29 September 1929
MPC designation (1161) Thessalia
Named after
Thessaly (Greek region)[2]
1929 SF · 1931 BB
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 87.76 yr (32,056 days)
Aphelion 3.4488 AU
Perihelion 2.8975 AU
3.1732 AU
Eccentricity 0.0869
5.65 yr (2,065 days)
0° 10m 27.84s / day
Inclination 9.3913°
Physical characteristics
Dimensions 21.498±0.184 km[3]

1161 Thessalia, provisional designation 1929 SF, is a dark background asteroid from the outer regions of the asteroid belt, approximately 21 kilometers in diameter. It was discovered on 29 September 1929, by German astronomer Karl Reinmuth at the Heidelberg-Königstuhl State Observatory.[5] It was named for the Greek region Thessaly.[2]

Orbit and classification[edit]

Thessalia is not a member of any known asteroid family.[6] It orbits the Sun in the outer main-belt at a distance of 2.9–3.4 AU once every 5 years and 8 months (2,065 days). Its orbit has an eccentricity of 0.09 and an inclination of 9° with respect to the ecliptic.[1] The body's observation arc begins at Heidelberg, five weeks after its official discovery observation.[5]

Physical characteristics[edit]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Thessalia measures 21.498 kilometers in diameter and its surface has an albedo of 0.065.[3][4]


As of 2017, no rotational lightcurve of Thessalia has been obtained from photometric observations. The asteroid's rotation period, poles and shape remain unknown.[7]


This minor planet was named for the Thessaly region in eastern Greece. The subsequently numbered minor planet 1162 Larissa was named after the region's capital. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 108).[2]


  1. ^ a b c d "JPL Small-Body Database Browser: 1161 Thessalia (1929 SF)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 7 September 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1161) Thessalia. Springer Berlin Heidelberg. p. 98. ISBN 978-3-540-00238-3. Retrieved 7 September 2017. 
  3. ^ a b 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:1406.6645Freely accessible. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 7 September 2017. 
  4. ^ a b 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 September 2017. 
  5. ^ a b "1161 Thessalia (1929 SF)". Minor Planet Center. Retrieved 7 September 2017. 
  6. ^ "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 7 September 2017. 
  7. ^ "LCDB Data for (1161) Thessalia". Asteroid Lightcurve Database (LCDB). Retrieved 7 September 2017. 

External links[edit]