| Discovery[1] | |
|---|---|
| Discovered by | Indiana University (Indiana Asteroid Program) |
| Discovery site | Goethe Link Obs. |
| Discovery date | 20 April 1950 |
| Designations | |
| (1575) Winifred | |
Named after | Winifred Sawtell (staff member atUSNO)[2] |
| 1950 HH · 1928 HG 1939 GK · 1950 HD1 1977 UH1 | |
| main-belt · Phocaea[3][4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 88.51 yr (32,327 days) |
| Aphelion | 2.7990AU |
| Perihelion | 1.9497 AU |
| 2.3743 AU | |
| Eccentricity | 0.1789 |
| 3.66yr (1,336 days) | |
| 158.55° | |
| 0° 16m 9.84s / day | |
| Inclination | 24.827° |
| 206.84° | |
| 348.40° | |
| Physical characteristics | |
| Dimensions | 9.31±1.0 km(IRAS)[5] 9.441±0.131 km[6] 9.45 km(derived)[3] 9.488±0.254[7] 10.66±0.43 km[8] |
| 125±2h[9] 129 h[10] | |
| 0.236±0.033[7] 0.2388±0.0311[6] 0.2452±0.064[5] 0.247±0.034[8] 0.3134(derived)[3] | |
| S[3] | |
| 11.36±1.19[11] · 12.0[1][3][8] · 12.3[6] | |
1575 Winifred, provisional designation1950 HH, is a stony Phocaeaasteroid andslow rotator from the inner regions of theasteroid belt, approximately 9.5 kilometers in diameter.
It was discovered on 20 April 1950, by astronomerRobert Curry Cameron ofIndiana University during theIndiana Asteroid Program atGoethe Link Observatory in Indiana, United States.[12] It was named afterWinifred Cameron, an astronomer at theUnited States Naval Observatory.[2]
The stonyS-type asteroid is a member of thePhocaea family (701), a group of asteroids with similar orbital characteristics, named after the family's namesake25 Phocaea.[4] It orbits the Sun at a distance of 1.9–2.8 AU once every 3 years and 8 months (1,336 days). Its orbit has aneccentricity of 0.18 and aninclination of 25° with respect to theecliptic.[1]
Winifred was first identified as1928 HG atJohannesburg Observatory in 1928, extending the body'sobservation arc by 22 years prior to its official discovery observation.[12]
In July 2009, a rotationallightcurve was obtained for this asteroid from photometric observations taken by American astronomerBrian D. Warner at his Palmer Divide Observatory in Colorado. It gave a well-definedrotation period of125±2 hours with an exceptionally high brightness amplitude of1.20 inmagnitude (U=3), and no sign of a non-principal axis rotation (NPAR).[9] The result supersedes a previous observation by French astronomerLaurent Bernasconi from May 2005, that gave a similar, yet less accurate period of 129 hours, and with a smaller amplitude of 0.51 in magnitude (U=1).[10]
According to the surveys carried out by the Infrared Astronomical Satellite,IRAS, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Winifred has analbedo of 0.24 to 0.25 and a diameter between 9.3 and 10.7 kilometers,[5][6][7][8] while theCollaborative Asteroid Lightcurve Link derives a higher albedo of 0.31 and a diameter of 9.5 kilometers with anabsolute magnitude of 12.0.[3]
Thisminor planet was named for a staff member of theUnited States Naval Observatory in Washington D.C.,Winifred Sawtell Cameron. The officialnaming citation was proposed by the discovering astronomer and published by theMinor Planet Center in December 1952 (M.P.C. 844).[2][13]
