| Discovery[1] | |
|---|---|
| Discovered by | E. Delporte |
| Discovery site | Uccle Obs. |
| Discovery date | 10 March 1929 |
| Designations | |
| (1128) Astrid | |
Named after | Astrid of Sweden (Queen consort of the Belgians)[2] |
| 1929 EB · 1949 QF2 1954 UL3 · 1964 VW 1972 LM1 · A917 SQ A920 JA | |
| main-belt · (middle) · Astrid[3] | |
| Adjectives | Astridian |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 97.07 yr (35,455 days) |
| Aphelion | 2.9171AU |
| Perihelion | 2.6577 AU |
| 2.7874 AU | |
| Eccentricity | 0.0465 |
| 4.65yr (1,700 days) | |
| 248.28° | |
| 0° 12m 42.48s / day | |
| Inclination | 1.0145° |
| 59.420° | |
| 234.37° | |
| Physical characteristics | |
| Dimensions | 33.28±9.67 km[4] 34.60 km(derived)[5] 34.69±2.1 km[6] 41.851±0.278 km[7] 41.97±0.72 km[8] 44.784±0.912 km[9] 45.03±10.37 km[10] 52.48±0.40 km[11] |
| 10.2±0.1h[12] 10.228±0.002 h[12] 10.229±0.0031 h[13] | |
| 0.031±0.004[11] 0.04±0.02[10] 0.0462±0.0181[9] 0.053±0.002[8] 0.06±0.03[4] 0.0644(derived)[5] 0.0770±0.010[6] | |
| SMASS =C[1] · C[5] | |
| 10.588±0.002(R)[13] · 10.70[6][8][9] · 10.80[11] · 10.90[1][4][5] · 10.93[10] · 11.02±0.35[14] | |
1128 Astrid, provisional designation1929 EB, is a carbonaceous Astridianasteroid from the central region of theasteroid belt. It is the parent body of theAstrid family and measures approximately 40 kilometers in diameter.
The asteroid was discovered by Belgian astronomerEugène Delporte at theRoyal Observatory of Belgium in Uccle on 10 March 1929, and later named forAstrid of Sweden, Queen consort of the Belgians.[2][15]
Astrid is the parent body of theAstrid family (515), a smallerasteroid family of nearly 500 carbonaceous members. It is located in the outermost central main-belt, near a prominentKirkwood gap, that marks the 5:2orbital resonance with Jupiter, and divides the asteroid belt into a central and outer part.[3][16][17]: 23
Astrid orbits the Sun at a distance of 2.7–2.9 AU once every 4 years and 8 months (1,700 days). Its orbit has aneccentricity of 0.05 and aninclination of 1° with respect to theecliptic.[1]
The asteroid was first identified asA917 SQ at the Simeiz Observatory in September 1917. The body'sobservation arc begins with its identification asA920 JA atHeidelberg Observatory in May 1920, nearly 9 years prior to its official discovery observation at Uccle.[15]
In theSMASS classification,Astrid is a carbonaceousC-type asteroid, which corresponds to the overallspectral type of the Astrid family.[1]
In September 2005, a rotationallightcurve ofAstrid was obtained from photometric observations by French amateur astronomerRené Roy. Lightcurve analysis gave arotation period of 10.228 hours with a brightness variation of 0.29magnitude (U=2+).[12] In October 2010, additional lightcurves were obtained at thePalomar Transient Factory inCalifornia, as well as by astronomers Eric Barbotin andRaoul Behrend, which gave a concurring period of 10.2 and 10.229 hours with an amplitude of 0.10 and 0.13 magnitude, respectively (U=1/2).[12][13]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite and theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Astrid measures between 33.28 and 52.48 kilometers in diameter and its surface has analbedo between 0.031 and 0.077.[4][6][7][8][9][10][11]
TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0644 and a diameter of 34.60 kilometers based on anabsolute magnitude of 10.9.[5]
1128 Astrid has been observed tooccult 2 stars, both events on 24 Jun 2023 UT.
Thisminor planet was named in memory ofAstrid of Sweden (1905–1935), Queen consort of the Belgians, who died at the age of 29 in a car accident while on vacation in Switzerland.[2] The official naming citation was mentioned inThe Names of the Minor Planets byPaul Herget in 1955 (H 106).[2]
