![]() Shape model of Annette from its lightcurve | |
Discovery [1] | |
---|---|
Discovered by | C. W. Tombaugh |
Discovery site | Lowell Obs. |
Discovery date | 5 October 1929 |
Designations | |
(2839) Annette | |
Named after | Annette Tombaugh (discoverer's daughter) [2] |
1929 TP ·1937 AB1 1939 UL ·1962 TE 1970 BB ·1972 XF1 1982 VP | |
main-belt · Flora [3] | |
Orbital characteristics [1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 87.67 yr (32,023 days) |
Aphelion | 2.5493 AU |
Perihelion | 1.8838 AU |
2.2166 AU | |
Eccentricity | 0.1501 |
3.30 yr (1,205 days) | |
200.55° | |
0° 17m 55.32s / day | |
Inclination | 4.8085° |
44.569° | |
6.8264° | |
Physical characteristics | |
5.41±0.86 km [4] 7.313±0.150 km [5] 7.562±0.122 km [6] | |
10.457±0.003 h [7] 10.4595±0.0001 h [8] | |
0.0563±0.0118 [6] 0.060±0.005 [5] 0.24 (assumed) [3] 0.47±0.22 [4] | |
S [3] | |
12.9 [1] ·12.92 [4] ·14.35 [3] [6] [8] | |
2839 Annette (prov. designation: 1929 TP) is a bright Flora asteroid from the inner regions of the asteroid belt. It was discovered on 5 October 1929, by American astronomer Clyde Tombaugh at Lowell Observatory during his search for Pluto. [9] The presumed S-type asteroid has a rotation period of 10.5 hours and measures approximately five kilometers (three miles) in diameter. It was named after the discoverer's daughter. [2]
Annette is a S-type asteroid and member of the Flora family, one of the largest families of stony asteroids. It orbits the Sun in the inner main-belt at a distance of 1.9–2.5 AU once every 3 years and 4 months (1,205 days). Its orbit has an eccentricity of 0.15 and an inclination of 5° with respect to the ecliptic. [1] Due to a precovery taken at Lowell Observatory, the body's observation arc was extended by 4 days prior to its official discovery observation. [9]
This minor planet was named after Clyde Tombaugh's daughter, Annette. [2] The approved naming citation was published by the Minor Planet Center on 22 June 1986 ( M.P.C. 10845). [10]
The first rotational lightcurve of Annette was obtained by American astronomer Brian Warner at his Palmer Divide Observatory, Colorado, in December 2005. It gave a rotation period of 10.457 hours with a brightness variation of 0.92 magnitude ( U=3- ). [7] In November 2006, a second lightcurve by astronomer Robert Buchheim at Altimira Observatory in southern California gave a concurring period of 10.4595 hours and an amplitude of 0.64 magnitude ( U=3 ). He also noted a significantly fainter absolute magnitude of 14.35 than previously reported. [8]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Annette measures between 5.41 and 7.562 kilometers in diameter and its surface has an albedo between 0.056 and 0.47, [4] [5] [6] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the largest member and namesake of its family – and calculates a diameter of 3.66 kilometers using Robert Buchheim's fainter absolute magnitude of 14.35. [3]