1186 Turnera, provisional designation 1929 PL, is a stony Eoan asteroid from the outer regions of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 1 August 1929, by South African astronomer Cyril Jackson at the Union Observatory in Johannesburg.[16] The asteroid was later named after British astronomer Herbert Hall Turner.[2]

1186 Turnera
Discovery [1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date1 August 1929
MPC designation(1186) Turnera
Named after
Herbert Hall Turner
(British astronomer)[2]
1929 PL · 1930 UO
1930 WL · 1932 CC
A919 SE
main-belt · (outer)
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc87.93 yr (32,115 days)
Aphelion3.3314 AU
Perihelion2.7190 AU
3.0252 AU
5.26 yr (1,922 days)
0° 11m 14.28s / day
Physical characteristics
Dimensions34.290±0.275 km[5]
35.56±2.0 km[6]
37.17±7.78 km[7]
39.06±0.57 km[8]
39.19±1.25 km[9]
39.691±0.354 km[10]
12.010 h[11]
12.066±0.004 h[12][a]
12.085±0.001 h[13]
15±2 h[14]
S (Tholen)[1] · S[3]
Sq (SMASS)[1]
B–V = 0.790[3]
U–B = 0.430[3]

Classification and orbitEdit

Turnera is a member of the Eos family (606), the largest asteroid family in the outer main-belt with nearly 10,000 known members.[4][17]:23 It orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 3 months (1,922 days). Its orbit has an eccentricity of 0.10 and an inclination of 11° with respect to the ecliptic.[1] Turnera was first identified as 1919 SE at Simeiz Observatory in September 1919. This observation, however, remains unused and the body's observation arc begins at Johannesburg with its official discovery observation in 1929.[16]

Physical characteristicsEdit

In the Tholen classification, Turnera is a common, stony S-type asteroid. In the SMASS classification, it is a Sq-type that transitions to the Q-type asteroids.[1] Generically, Eoan asteroids are also characterized as K-type asteroids with an albedo of 0.13.[17]:23


In January 2016, the best-rated rotational lightcurve of Turnera was obtained from photometric observations by the Spanish amateur astronomer group OBAS, Observadores de Asteroids. Lightcurve analysis gave a well-defined rotation period of 12.085 hours with a brightness variation of 0.31 magnitude (U=3).[13] Previously, American astronomer Brian Warner obtained a similar period of 12.066 hours and an amplitude of 0.34 magnitude at his Palmer Divide Observatory (716) in Colorado (U=2+).[12][a]

Other lightcurve observations were made by French amateur astronomer Laurent Bernasconi (15±2 hours; Δmag of 0.25; U=2+) in February 2006,[14] and by Italian astronomer Maria A. Barucci (12.010 hours; Δmag of 0.20; U=2) in August 1987.[11]

Diameter and albedoEdit

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, Turnera measures between 34.290 and 39.691 kilometers in diameter and its surface has an albedo between 0.12 and 0.2919.[5][6][7][8][9][10]

The Collaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is, an albedo of 0.2919 and a diameter of 35.56 kilometers with an absolute magnitude of 9.20.[3]


This minor planet was named after British astronomer Herbert Hall Turner (1861–1930), director of the Radcliffe Observatory at Oxford University.[2] He is also credited with coining the term "parsec". The official naming citation was published in Paul Herget's The Names of the Minor Planets in 1955 (H 110).[2]


  1. ^ a b Lightcurve plot of 1186 Turnera, Palmer Divide Observatory, Brian D. Warner (2006)


  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1186 Turnera (1929 PL)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 17 August 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(1186) Turnera". Dictionary of Minor Planet Names – (1186) Turnera. Springer Berlin Heidelberg. p. 99. doi:10.1007/978-3-540-29925-7_1187. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (1186) Turnera". Asteroid Lightcurve Database (LCDB). Retrieved 17 August 2017.
  4. ^ a b "Asteroid 1186 Turnera – Nesvorny HCM Asteroid Families V3.0". Small Bodies Data Ferret. Retrieved 26 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 17 August 2017.
  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. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  7. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 17 August 2017.
  8. ^ 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 17 October 2019. (online, AcuA catalog p. 153)
  9. ^ 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 17 August 2017.
  10. ^ 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". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  11. ^ a b Barucci, M. A.; di Martino, M.; Fulchignoni, M. (May 1992). "Rotational properties of small asteroids - Photoelectric observations". Astronomical Journal. 103: 1679–1686. Bibcode:1992AJ....103.1679B. doi:10.1086/116185. ISSN 0004-6256.
  12. ^ a b Warner, Brian D.; Higgins, David (December 2006). "The lightcurves of 1043 Beate and 1186 Turnera". The Minor Planet Bulletin. 33 (4): 104–105. Bibcode:2006MPBu...33..104W. ISSN 1052-8091. Retrieved 17 August 2017.
  13. ^ a b Aznar Macias, Amadeo; Carreno Garcerain, Alfonso; Arce Masego, Enrique; Brines Rodriguez, Pedro; Lozano de Haro, Juan; Fornas Silva, Alvaro; et al. (July 2016). "Twenty-one Asteroid Lightcurves at Group Observadores de Asteroides (OBAS): Late 2015 to Early 2016". The Minor Planet Bulletin. 43 (3): 257–263. Bibcode:2016MPBu...43..257A. ISSN 1052-8091. Retrieved 17 August 2017.
  14. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1186) Turnera". Geneva Observatory. Retrieved 17 August 2017.
  15. ^ 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 17 August 2017.
  16. ^ a b "1186 Turnera (1929 PL)". Minor Planet Center. Retrieved 17 August 2017.
  17. ^ a b Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). Identification and Dynamical Properties of Asteroid Families. Asteroids IV. pp. 297–321. arXiv:1502.01628. Bibcode:2015aste.book..297N. doi:10.2458/azu_uapress_9780816532131-ch016. ISBN 9780816532131.

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