| Discovery[1] | |
|---|---|
| Discovered by | L. Boyer |
| Discovery site | Algiers Obs. |
| Discovery date | 24 November 1930 |
| Designations | |
| (1177) Gonnessia | |
Named after | François Gonnessiat[2] (French astronomer) |
| 1930 WA · A923 RO | |
| main-belt · (outer)[1][3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 86.28 yr (31,513 days) |
| Aphelion | 3.4519AU |
| Perihelion | 3.2440 AU |
| 3.3480 AU | |
| Eccentricity | 0.0310 |
| 6.13yr (2,238 days) | |
| 344.46° | |
| 0° 9m 39.24s / day | |
| Inclination | 15.071° |
| 252.16° | |
| 241.85° | |
| Physical characteristics | |
| Dimensions | 91.98±9.9 km[4] 93.50±1.01 km[5] 99.27±43.41 km[6] 104.63±33.73 km[7] |
| 6.81±0.01h(poor)[8] 10 h[9] 28.89±0.02 h[9] 30.51±0.02 h[10][11] 30.51 h[a] 82±5 h[12][b] | |
| 0.03±0.02[7] 0.03±0.04[6] 0.0398±0.010[4] 0.040±0.001[5] | |
| Tholen = XFU[1][3] · X[13] B–V = 0.668[1] U–B = 0.244[1] | |
| 8.86±0.13(R)[a] · 9.24[3] · 9.24±0.139[14] · 9.30[4][5][7] · 9.35[6] · 9.4[1] · 9.66±0.60[13] | |
1177 Gonnessia, provisional designation1930 WA, is a dark backgroundasteroid from the outer regions of theasteroid belt, approximately 99 kilometers in diameter. It was discovered on 24 November 1930, by French astronomerLouis Boyer at theAlgiers Observatory in Algeria, North Africa, and named after astronomerFrançois Gonnessiat.[2][15]
Gonnessia is not a member of any knownasteroid family. It orbits the Sun in theouter main-belt at a distance of 3.2–3.5 AU once every 6 years and 2 months (2,238 days). Its orbit has aneccentricity of 0.03 and aninclination of 15° with respect to theecliptic.[1]
The asteroid was first observed asA923 RO atSimeiz Observatory in September 1923. The body'sobservation arc begins atHeidelberg Observatory, three weeks after its official discovery observation at Algiers Bouzaréah.[15]
In theTholen classification,Gonnessia is classified as an asteroid with an unusual spectrum (XFU).[1] It was also characterized as anX-type asteroid byPanSTARRS photometric survey.[13]
Several rotationallightcurves ofGonnessia were obtained since 2002. The best rated photometric observations were taken in 2010, by American astronomerRobert Stephens at the Goat Mountain Astronomical Research Station (G79) and Santana Observatory (646) in California. Lightcurve analysis gave arotation period of 30.51 hours with a brightness amplitude of 0.10magnitude, indicative for a spheroidal shape (U=3-/3-).[10][11][a] Previous observations byBrian Warner gave a longer period of 82 hours based on sparse photometry (U=2-).[12][b] While not being aslow rotator,Gonnessia has a notably slower spin rate than most asteroids.
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Gonnessia measures between 91.98 and 104.63 kilometers in diameter and its surface has analbedo between 0.03 and 0.040.[4][5][6][7]
TheCollaborative Asteroid Lightcurve Link adopts the results obtained by IRAS, that is an albedo of 0.0398 with a diameter of 91.98 kilometers. It also takesPetr Pravec's revisedabsolute magnitude from WISE of 9.24.[3][4][14]
Thisminor planet was named after astronomerFrançois Gonnessiat (1856–1934), who was an observer ofcomets and adiscoverer of minor planets. Gonnessiat was also a director of the discoveringAlgiers Observatory and headed theQuito Astronomical Observatory in Ecuador as well.[2] The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 109).[2]
