![]() Modelled shape of Ilona from its lightcurve | |
Discovery[1] | |
---|---|
Discovered by | K. Reinmuth |
Discovery site | Heidelberg Obs. |
Discovery date | 3 March 1927 |
Designations | |
(1182) Ilona | |
Named after | unknown[2] |
1927 EA · A915 RD | |
main-belt · (inner)[3] | |
Orbital characteristics[1] | |
Epoch 4 September 2017 (JD 2458000.5) | |
Uncertainty parameter 0 | |
Observation arc | 90.33 yr (32,993 days) |
Aphelion | 2.5261 AU |
Perihelion | 1.9930 AU |
2.2596 AU | |
Eccentricity | 0.1180 |
3.40 yr (1,241 days) | |
328.01° | |
0° 17m 24.72s / day | |
Inclination | 9.3881° |
336.38° | |
63.035° | |
Physical characteristics | |
Dimensions | 12.67±2.95 km[4] 13.29±2.48 km[5] 13.448±0.074 km[6] 14.09 km (derived)[3] 14.162±0.257[7] 14.26±0.8 km[8] 17.88±0.62 km[9] |
14.938±0.005 h[10] 29.8±0.1 h[11] 29.853±0.0627 h[12] | |
0.175±0.014[9] 0.2039 (derived)[3] 0.22±0.11[5] 0.221±0.016[7] 0.2624±0.030[8] 0.29±0.13[4] 0.2957±0.0367[6] | |
S[3] | |
11.04±0.96[13] · 11.3[6][8][9] · 11.50[4][7] · 11.536±0.004 (R)[12] · 11.6[1][3] · 11.77[5] | |
1182 Ilona, provisional designation 1927 EA, is a stony asteroid from the inner regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at the Heidelberg Observatory on 3 March 1927, and later named Ilona. Any reference to its name is unknown.[14][2]
Ilona orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 5 months (1,241 days). Its orbit has an eccentricity of 0.12 and an inclination of 9° with respect to the ecliptic.[1] The asteroid was first identified as A915 RD at Bergedorf Observatory in September 1915. The body's observation arc, however, begins at Heidelberg one night after its official discovery observation.[14]
Any reference to a person or occurrence of this minor planet's name is unknown. The name was suggested by German astronomer Gustav Stracke.[2]
Among the many thousands of named minor planets, Ilona is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between 164 Eva and 1514 Ricouxa and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois, Johann Palisa, Max Wolf and Karl Reinmuth.[15]
Ilona is an assumed stony S-type asteroid.[3]
Three rotational lightcurve of Ilona were obtained from photometric observations. Lightcurve analysis gave a rotation period of 29.8 hours (including an alternative period solution 14.938 hours, or half the period) with a brightness variation of 0.98 to 1.20 magnitude (U=2/2/2).[10][11][12] A high brightness amplitude typically indicates that the body has a non-spheroidal shape.
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Ilona measures between 12.67 and 17.88 kilometers in diameter and its surface has an albedo between 0.175 and 0.2957.[4][5][6][7][8][9] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2039 and calculates a diameter of 14.09 kilometers based on an absolute magnitude of 11.6.[3]