| Discovery[1] | |
|---|---|
| Discovered by | P. Wild |
| Discovery site | Zimmerwald Obs. |
| Discovery date | 19 April 1974 |
| Designations | |
| (1938) Lausanna | |
Named after | Lausanne(Swiss city)[2] |
| 1974 HC · 1934 KA 1947 DB · 1950 CO 1955 VK · 1957 EH 1962 WB1 · 1967 ED1 1971 OX · 1972 XY1 | |
| main-belt · Flora[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 82.99 yr (30,312 days) |
| Aphelion | 2.5938AU |
| Perihelion | 1.8796 AU |
| 2.2367 AU | |
| Eccentricity | 0.1597 |
| 3.35yr (1,222 days) | |
| 329.17° | |
| 0° 17m 40.56s / day | |
| Inclination | 3.3343° |
| 171.69° | |
| 64.830° | |
| Physical characteristics | |
| Dimensions | 7.638±0.124 km[4] 7.82 km(calculated)[3] 8.214±0.077 km[5] |
| 2.748±0.001h[a] 2.748±0.001 h[6] | |
| 0.1660±0.0301[5] 0.192±0.055[4] 0.24(assumed)[3] | |
| S[3][7] | |
| 12.60±0.26[7] · 12.7[1][3] · 13.0[5] | |
1938 Lausanna, provisional designation1974 HC, is a stony Florianasteroid from the inner regions of theasteroid belt. It is approximately 8 kilometers in diameter, and was discovered on 19 April 1974 by Swiss astronomer,Paul Wild atZimmerwald Observatory near Bern, Switzerland.[8] It is named for the city ofLausanne.[2]
Lausanna is aS-type asteroid and member of theFlora family, one of the largest collisional populations of stony asteroids in the main-belt. It orbits the Sun in theinner main-belt at a distance of 1.9–2.6 AU once every 3 years and 4 months (1,222 days). Its orbit has aneccentricity of 0.16 and aninclination of 3° with respect to theecliptic.[1] It was first identified as1934 KA atJohannesburg Observatory in 1934, extending the body'sobservation arc by 40 years prior to its official discovery observation at Zimmerwald.[8]
In March 2014, two rotationallightcurves ofLausanna were obtained from photometric observations by American astronomerBrian Skiff and by Johan Warell at Lindby Observatory (K60) in Sweden. Lightcurve analysis gave an identicalrotation period of 2.748 hours with a brightness amplitude of 0.13 and 0.12magnitude, respectively (U=3-/2).[a][6] The short period is near the threshold of 2.2 hours forfast rotating asteroids.
According to the space-based survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Lausanna measures 7.64 and 8.21 kilometers in diameter, and its surface has analbedo of 0.166 and 0.192, respectively.[4][5] TheCollaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from8 Flora, the largest member and namesake of its family – and calculates a diameter of 7.82 kilometers based on anabsolute magnitude of 12.7.[3]
Thisminor planet was named for the Swiss city ofLausanne, located in the French-speaking part of the country. The discoverer Paul Wild, known for his unconventional minor-planet namings, discovered three more asteroids during winter of 1973/74. He named these1935 Lucerna,1936 Lugano and1937 Locarno, after the Swiss citiesLucerne,Lugano andLocarno, respectively, hence composing analliterated quartet of sequentially numbered, thematically named minor planets. The officialnaming citation was published by theMinor Planet Center on 1 April 1978 (M.P.C. 4358).[9]
