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.[7] It was named for the Greek region Thessaly.[3]

1161 Thessalia
Discovery[1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date29 September 1929
Designations
(1161) Thessalia
Pronunciation/θɪˈsliə/[2]
Named after
Thessaly (Greek region)[3]
1929 SF · 1931 BB
main-belt · (outer)
background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.76 yr (32,056 days)
Aphelion3.4488 AU
Perihelion2.8975 AU
3.1732 AU
Eccentricity0.0869
5.65 yr (2,065 days)
213.02°
0° 10m 27.84s / day
Inclination9.3913°
72.567°
309.20°
Physical characteristics
Dimensions21.498±0.184 km[5]
0.065±0.010[6]
11.2[1]

Orbit and classification

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Thessalia is a non-family asteroid from the main belt's background population.[4] 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.[7]

Physical characteristics

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Diameter and albedo

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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.[5][6]

Lightcurves

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As of 2017, no rotational lightcurve of Thessalia has been obtained from photometric observations. The asteroid's rotation period, poles and shape remain unknown.[8]

Naming

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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).[3]

References

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  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. ^ "Thessalian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ a b c Schmadel, Lutz D. (2007). "(1161) Thessalia". Dictionary of Minor Planet Names – (1161) Thessalia. Springer Berlin Heidelberg. p. 98. doi:10.1007/978-3-540-29925-7_1162. ISBN 978-3-540-00238-3.
  4. ^ a b "Asteroid 1161 Thessalia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 28 October 2019.
  5. ^ 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:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 7 September 2017.
  6. ^ 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:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 7 September 2017.
  7. ^ a b "1161 Thessalia (1929 SF)". Minor Planet Center. Retrieved 7 September 2017.
  8. ^ "LCDB Data for (1161) Thessalia". Asteroid Lightcurve Database (LCDB). Retrieved 7 September 2017.
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