Contents

1186 Turnera

1186 Turnera

Shape model of Turnera from its lightcurve
Discovery[1]
Discovered by	C. Jackson
Discovery site	Johannesburg Obs.
Discovery date	1 August 1929
Designations
MPC designation	(1186) Turnera
Named after	Herbert Hall Turner (British astronomer)[2]
Alternative designations	1929 PL · 1930 UO 1930 WL · 1932 CC A919 SE
Minor planet category	main-belt · (outer) Eos[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	87.93 yr (32,115 days)
Aphelion	3.3314 AU
Perihelion	2.7190 AU
Semi-major axis	3.0252 AU
Eccentricity	0.1012
Orbital period (sidereal)	5.26 yr (1,922 days)
Mean anomaly	252.20°
Mean motion	0° 11m 14.28s / day
Inclination	10.752°
Longitude of ascending node	42.988°
Argument of perihelion	295.00°
Physical characteristics
Dimensions	34.290±0.275km[5] 35.56±2.0km[6] 37.17±7.78km[7] 39.06±0.57km[8] 39.19±1.25km[9] 39.691±0.354km[10]
Synodic rotation period	12.010 h[11] 12.066±0.004h[12][a] 12.085±0.001h[13] 15±2h[14]
Geometric albedo	0.12±0.04[7] 0.2350±0.0371[10] 0.240±0.026[9] 0.247±0.008[8] 0.2919±0.036[6]
Spectral type	S (Tholen)[1] · S[3] Sq(SMASS)[1] B–V = 0.790[3] U–B = 0.430[3]
Absolute magnitude (H)	9.20[1][3][6][7][8][9][10] 9.90±0.38[15]

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]

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 SEatSimeiz 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]

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 lightcurveofTurnera 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]

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 ObservatoryatUniversity of Oxford.^[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]

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1186 TurneraatAstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1186 Turnera at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters