 Orbital diagram | |
| Discovery[1] | |
|---|---|
| Discovered by | A. Charlois |
| Discovery site | Nice Obs. |
| Discovery date | 19 March 1893 |
| Designations | |
| (364) Isara | |
| Pronunciation | /ˈɪsərə/[2][3][4] |
Named after | Isère River (river in France)[5] |
| 1893 T · 1976 AB | |
| main-belt · (inner) Flora[6][7][8] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 117.10 yr (42,772 days) |
| Aphelion | 2.5532AU |
| Perihelion | 1.8881 AU |
| 2.2206 AU | |
| Eccentricity | 0.1498 |
| 3.31yr (1,209 days) | |
| 322.26° | |
| 0° 17m 52.08s / day | |
| Inclination | 6.0033° |
| 105.54° | |
| 312.78° | |
| Physical characteristics | |
| Dimensions | 25.901±0.665 km[9] 27.99±1.0 km[10] 28.78±0.30 km[11] 35.209±0.253 km[12] |
| 9.151±0.007h[13] 9.155 h[a] 9.156±0.001 h[14][b] 9.1570±0.0005 h[8] 9.15751±0.00005 h[15] | |
| 0.1625±0.0334[12] 0.244±0.006[11] 0.2566±0.020[10] 0.300±0.037[9] | |
| Tholen =S[1] · S[6] B–V = 0.912[1] U–B = 0.538[1] | |
| 9.86[1][6][9][10][11][12] | |
364 Isara[c] is a stony Florianasteroid from the inner regions of theasteroid belt, approximately 27 kilometers in diameter. It was discovered on 19 March 1893, by French astronomerAuguste Charlois at theNice Observatory in southeast France.[16] The asteroid was named after theIsère River in France.[5]
Isara is a member of theFlora family (402), a giantasteroid family and the largest family of stony asteroids in the main-belt.[6][7][17]: 23
It orbits the Sun in theinner main-belt at a distance of 1.9–2.6 AU once every 3 years and 4 months (1,209 days). Its orbit has aneccentricity of 0.15 and aninclination of 6° with respect to theecliptic.[1] The body'sobservation arc begins atVienna Observatory in April 1900, seven years after to its official discovery observation at Nice.[16]
In theTholen classification,Isara is a common stonyS-type asteroid, which agrees with the overallspectral type of the Flora family.[1][17]: 23
In 2009,photometric observations ofIsara were made by American astronomerBrian Warner at the Palmer Divide Observatory (716) in Colorado,[b] by amateur astronomerRené Roy at Blauvac Observatory (627) in France, and by a group of Polish astronomers led by Agnieszka Kryszczyńska of thePolish Astronomical Society. The resulting asymmetricallightcurves showed a synodicrotation period between 9.151 and 9.157 hours with a brightness variation between 0.30 and 0.40 inmagnitude (U=3/3/2+).[13][14][8]
The results agree with the first rotational lightcurve was already obtained in the 1960s (U=2).[a]
In 2013, an international study modeled a lightcurve with a concurring period of 9.15751 hours and found twospin axis of (282.0°, 44.0°) and (86.0°, 42.0°) inecliptic coordinates (λ, β) (Q=2).[15]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Isara measures between 25.901 and 35.209 kilometers in diameter and its surface has analbedo between 0.1625 and 0.300.[9][10][11][12]
TheCollaborative Asteroid Lightcurve Link adopt the results obtained by IRAS, that is, an albedo of 0.2566 and a diameter of 27.99 kilometers based on anabsolute magnitude of 9.86.[6]
364 Isara has been observed tooccult 4 stars between 2002 and 2023.
Thisminor planet was named after theIsère River in south eastern France. ("Isara" is an early name for this river.) The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 40).[5]
