2608 Seneca

2608 Seneca

Discovery
Discovered by	H.-E. Schuster
Discovery site	La Silla Obs.
Discovery date	17 February 1978
Designations
Pronunciation	/ˈsɛnᵻkə/ sen-IK-ə
Named after	Seneca the Younger (Roman philosopher)
Alternative names	1978 DA
Minor planet category	NEO · Amor
Orbital characteristics
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 1
Observation arc	38.92 yr (14,217 days)
Aphelion	3.9532 AU
Perihelion	1.0777 AU
Semi-major axis	2.5154 AU
Eccentricity	0.5716
Orbital period	3.99 yr (1,457 days)
Mean anomaly	353.12°
Inclination	14.682°
Longitude of ascending node	167.37°
Argument of perihelion	37.350°
Earth MOID	0.1321 AU · 51.5 LD
Physical characteristics
Dimensions	0.9 km 1.0±0.3
Rotation period	8 h
Geometric albedo	0.15±0.03 0.20 (derived) 0.21
Spectral type	Tholen = S  · S  B–V = 0.826 U–B = 0.454
Absolute magnitude (H)	17.52 · 17.59 · 17.73

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 Schuster at ESO's La Silla Observatory in northern Chile, and named after Roman philosopher Seneca.

Orbit

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.

The body's observation arc begins with its official discovery observation in 1978, as no precoveries were taken, and no prior identifications were made.

Close approaches

Seneca has an Earth minimum orbital intersection distance of , which corresponds to 51.5 lunar distances. On 22 March 2062, it will pass from the Earth.

Physical characteristics

In the Tholen taxonomy, Seneca is a stony S-type asteroid.

Photometry

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).

Radiometry

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 albedo of 0.15±0.03.

Diameter and albedo

The Minor Planet Center classifies Seneca as an object larger than 1 kilometer ("1+ KM Near-Earth Object"), 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. 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.

Naming

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". The approved naming citation was published by the Minor Planet Center on 8 April 1982 (M.P.C. 6835). The lunar crater Seneca was also named in his honor.

External links

• Hazards Due to Comets and Asteroids, Tom Gehrels (1994/5)
• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Template:NeoDys
• Template:ESA-SSA
• 2608 Seneca at the JPL Small-Body Database

• Discovery · Orbit diagram · Orbital elements · Physical parameters