2608 Seneca, provisional designation , is a stony

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

and sub-kilometer

near-Earth object A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...

of the Amor group, approximately 0.9 kilometers in diameter. It was discovered on 17 February 1978, by German astronomer

Hans-Emil Schuster Hans-Emil Schuster (born 19 September 1934 in Hamburg) is a German astronomer and a discoverer of minor planets and comets, who retired in October 1991. He worked at Hamburg Observatory at Bergedorf and European Southern Observatory (ESO), and ...

ESO The European Southern Observatory is an astronomical research organisation. ESO may also refer to: *Employee stock option (also: executive stock option) *'' Ether Saga Odyssey'', a fantasy massively multiplayer online role-playing game *''The Elde ...

La Silla Observatory La Silla Observatory is an astronomical observatory in Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several other telescopes are also located at the site and are partly maintained by ESO. The observato ...

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 Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.57 and an

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

of 15 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of Earth's orbit, Earth around the Sun. It was a central concept in a number of ancient sciences, providing the framework for key measurements in astronomy, astrology and calendar-making. Fr ...

. The body's

observation arc In observational astronomy, the observation arc (or arc length) of a Solar System body is the time period between its earliest and latest observations, used for tracing the body's path. It is usually given in days or years. The term is mostly use ...

begins with its official discovery observation in 1978, as no

precoveries In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This ha ...

were taken, and no prior identifications were made.

Close approaches

''Seneca'' has an ''Earth

minimum orbital intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits of ...

'' of , which corresponds to 51.5 lunar distances. On 22 March 2062, it will pass from the Earth.

Physical characteristics

In the

Tholen Tholen () is a 25,000 people municipality in the southwest of the Netherlands. The municipality of Tholen takes its name from the town of Tholen, which is the largest population center in the municipality. The municipality consists of two peninsu ...

taxonomy, ''Seneca'' is a stony

S-type asteroid S-type (stony-type or silicaceous-type) asteroids are asteroids with a spectral type that is indicative of a siliceous (i.e. stony) mineralogical composition, hence the name. They have relatively high density. Approximately 17% of asteroids are ...

Photometry

In March 1978, a photometric observations taken by Degewij and Lebofsky at the

Lunar and Planetary Laboratory The Lunar and Planetary Laboratory (LPL) is a research center for planetary science located in Tucson, Arizona. It is also a graduate school, constituting the Department of Planetary Sciences at the University of Arizona. LPL is one of the wor ...

, Arizona, using a 154-cm reflector, gave a rotational

lightcurve In astronomy, a light curve is a graph (discrete mathematics), graph of the Radiance, light intensity of a celestial object or region as a function of time, typically with the magnitude (astronomy), magnitude of light received on the ''y''-axis ...

with a

rotation period In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the objec ...

of 8 hours and a brightness amplitude of 0.4 (0.5)

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

().

Radiometry

In addition, radiometric observations by L. and M. Lebofsky with the 71-cm reflector gave a mean-diameter of kilometers and

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

of .

Diameter and albedo

The

Minor Planet Center The Minor Planet Center (MPC) is the official body for observing and reporting on minor planets under the auspices of the International Astronomical Union (IAU). Founded in 1947, it operates at the Smithsonian Astrophysical Observatory. Funct ...

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 Anton M.J. "Tom" Gehrels (February 21, 1925 – July 11, 2011) was a Dutch–American astronomer, Professor of Planetary Sciences, and Astronomer at the University of Arizona, Tucson. Biography Youth and education Gehrels was born at Ha ...

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 According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''minor ...

was named after Roman philosopher and statesman

Lucius Annaeus Seneca Lucius Annaeus Seneca the Younger ( ; AD 65), usually known mononymously as Seneca, was a Stoicism, Stoic philosopher of Ancient Rome, a statesman, a dramatist, and in one work, a satirist, from the post-Augustan age of Latin literature. Seneca ...

(c. 4 BC – AD 65), also known as "Seneca the Younger" or simply "Seneca". The approved naming citation was published by the

on 8 April 1982 (). The lunar crater '' Seneca'' was also named in his honor.