2608 Seneca, provisional designation 1978 DA, is a stony asteroid and sub-kilometer near-Earth object of the Amor group, approximately 0.9 kilometers in diameter. It was discovered on 17 February 1978, by German astronomer Hans-Emil SchusteratESO's La Silla Observatory in northern Chile, and named after Roman philosopher Seneca.[3][4]
| Discovery [1] | |
|---|---|
| Discovered by | H.-E. Schuster |
| Discovery site | La Silla Obs. |
| Discovery date | 17 February 1978 |
| Designations | |
| (2608) Seneca | |
| Pronunciation | /ˈsɛnɪkə/ SEN-ik-ə[2] |
Named after | Seneca the Younger (Roman philosopher)[3] |
| 1978 DA | |
| NEO · Amor [1][4] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter1 | |
| Observation arc | 38.92 yr (14,217 days) |
| Aphelion | 3.9532 AU |
| Perihelion | 1.0777 AU |
| 2.5154 AU | |
| Eccentricity | 0.5716 |
| 3.99 yr (1,457 days) | |
| 353.12° | |
| 0° 14m 49.56s / day | |
| Inclination | 14.682° |
| 167.37° | |
| 37.350° | |
| Earth MOID | 0.1321 AU · 51.5 LD |
| Physical characteristics | |
| Dimensions | 0.9 km[1][5][6] 1.0±0.3[6] |
| 8 h[6] | |
| 0.15±0.03[6] 0.20 (derived)[5] 0.21[1] | |
| Tholen = S [1] · S [5] B–V = 0.826[1] U–B = 0.454[1] | |
| 17.52[1] · 17.59[5][7] · 17.73[6] | |
Seneca orbits the Sun at a distance of 1.1–4.0 AU once every 3 years and 12 months (1,457 days). Its orbit has an eccentricity of 0.57 and an inclination of 15° with respect to the ecliptic.[1]
The body's observation arc begins with its official discovery observation in 1978, as no precoveries were taken, and no prior identifications were made.[4]
Seneca has an Earth minimum orbital intersection distance of 0.1321 AU (19,800,000 km), which corresponds to 51.5 lunar distances.[1] On 22 March 2062, it will pass 0.254 AU (38,000,000 km) from the Earth.[8]
In the Tholen taxonomy, Seneca is a stony S-type asteroid.[1]
In March 1978, a photometric observations taken by Degewij and Lebofsky at the Lunar and Planetary Laboratory, Arizona, using a 154-cm reflector, gave a rotational lightcurve with a rotation period of 8 hours and a brightness amplitude of 0.4 (0.5) magnitude (U=2).[6]
In addition, radiometric observations by L. and M. Lebofsky with the 71-cm reflector gave a mean-diameter of 1.0±0.3 kilometers and albedoof0.15±0.03.[6]
The Minor Planet Center classifies Seneca as an object larger than 1 kilometer ("1+ KM Near-Earth Object"),[4] while Collaborative Asteroid Lightcurve Link derives an albedo of 0.20 and a diameter of 0.9 kilometers based on an absolute magnitude of 17.59.[5] In 1994, astronomer Tom Gehrels published a diameter of 0.9 kilometers with an albedo of 0.21 in his Hazards Due to Comets and Asteroids.[1]
This minor planet was named after Roman philosopher and statesman Lucius Annaeus Seneca (c. 4 BC – AD 65), also known as "Seneca the Younger" or simply "Seneca".[3] The approved naming citation was published by the Minor Planet Center on 8 April 1982 (M.P.C. 6835).[9] The lunar crater Seneca was also named in his honor.[3]
