| Discovery[1] | |
|---|---|
| Discovered by | E. L. Johnson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 10 July 1951 |
| Designations | |
| (1609) Brenda | |
Named after | Brenda(discoverer's granddaughter)[2] |
| 1951 NL · 1925 EA 1934 JB · 1947 WB 1950 HD · 1954 EP 1954 HE | |
| main-belt · (middle)[3] Gersuind | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 82.98 yr (30,310 days) |
| Aphelion | 3.2255AU |
| Perihelion | 1.9432 AU |
| 2.5844 AU | |
| Eccentricity | 0.2481 |
| 4.15yr (1,518 days) | |
| 309.08° | |
| 0° 14m 13.92s / day | |
| Inclination | 18.628° |
| 105.23° | |
| 229.14° | |
| Physical characteristics | |
| Dimensions | 26.27±6.75 km[4] 27.96±0.48 km[5] 29.59 km(derived)[3] 29.64±1.7 km(IRAS:6)[6] |
| 19.46h[7] 23±1 h[8] | |
| 0.1078(derived)[3] 0.1147±0.014(IRAS:6)[6] 0.13±0.05[4] 0.133±0.005[5] | |
| S[3] B–V = 0.860[1] U–B = 0.390[1] | |
| 10.50[4] · 10.6[1] · 10.61[6][5] · 10.68[3][7] | |
1609 Brenda, provisional designation1951 NL, is a stonyasteroid from the central region of theasteroid belt, approximately 28 kilometers in diameter. It was discovered on 10 July 1951, by South African astronomerErnest Johnson at theJohannesburg Observatory in South Africa, and named after his granddaughter, Brenda.[9]
TheS-type asteroid orbits the Sun in thecentral main-belt at a distance of 1.9–3.2 AU once every 4 years and 2 months (1,518 days). Its orbit has aneccentricity of 0.25 and aninclination of 19° with respect to theecliptic.[1]Brenda was first identified as1925 EA atSimeiz Observatory in 1925. Itsobservation arc begins 17 years prior to its official discovery observation, with its identification1934 JB, also made at Simeiz.[9]
American astronomerRichard Binzel obtained the first rotationallightcurve ofBrenda in June 1984. It gave arotation period of 19.46 hours with a brightness variation of 0.16magnitude (U=2).[7] In June 2006, a period of23±1 with an amplitude of 0.26 magnitude was derived from photometric observations made by French amateur astronomerRené Roy (U=2).[8]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Brenda measures between 26.27 and 29.64 kilometers in diameter, and its surface has analbedo between 0.115 and 0.133.[4][5][6] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.1078 and a diameter of 29.59 kilometers with anabsolute magnitude of 10.68.[3]
Thisminor planet was named by the discoverer for his granddaughter, Brenda.[2] The officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3931).[10] Ernest Johnson is also known for the discovery of the periodic comet48P/Johnson, using the Franklin-Adams Star Camera.
