2308 Schilt, provisional designation , is a stony Eunomia

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

from the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 6 May 1967, by Argentine astronomer Carlos Cesco together with American astronomer Arnold Klemola at the Yale–Columbia Southern Station at Leoncito Astronomical Complex in Argentina.

Orbit and classification

''Schilt'' is a member of the

Eunomia family The Eunomia or Eunomian family () is a large asteroid family of S-type asteroids named after the asteroid 15 Eunomia. It is the most prominent family in the intermediate asteroid belt and the 6th-largest family with nearly six thousand known members ...

, a large group of stony asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun in the

central Central is an adjective usually referring to being in the center of some place or (mathematical) object. Central may also refer to: Directions and generalised locations * Central Africa, a region in the centre of Africa continent, also known as ...

main-belt at a distance of 2.1–3.0 AU once every 4 years and 1 month (1,487 days). Its orbit has an eccentricity of 0.17 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 Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 14 ° with respect to the ecliptic. The asteroids

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 discovery in 1967. However, the first (unused)

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

was already taken at

Heidelberg Observatory Heidelberg (; Palatine German: ') is a city in the German state of Baden-Württemberg, situated on the river Neckar in south-west Germany. As of the 2016 census, its population was 159,914, of which roughly a quarter consisted of students. ...

in 1921.

Physical characteristics

In the SMASS taxonomy, ''Schilt'' has been characterized as a common

S-type asteroid S-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 of this type, making it the second ...

Rotation period

A rotational lightcurve was obtained based on photometric observations at the Australian Oakley Southern Sky Observatory in August 2012. The lightcurve showed a period of hours with a brightness amplitude of 0.44 in magnitude (). A previous observation by Argentine astronomer Salvador Mazzone at the Observatorio Astronómico Salvador gave a similar period of with an amplitude of 0.42 in magnitude ().

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite (

IRAS The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mo ...

) and NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...

with its subsequent NEOWISE mission, the asteroid measures between 13.8 and 17.7 kilometers in diameter and its surface has an

albedo Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...

in the range of 0.10–0.17. The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.10 and a diameter of 17.5 kilometers.

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 Dutch–American astronomer

Jan Schilt Jan Schilt (3 February 1894, Gouda – 9 January 1982, Englewood, New Jersey) was a Dutch-American astronomer, inventor of the Schilt photometer. Biography Schilt was born in 1894 in the Netherlands, and educated there under Jacobus Kapteyn. He ...

(1894–1982), one of the founders of the discovering Columbia–Yale Southern Station in the early 1960s, for which he collaborated with local astronomer and with Yale's Dirk Brouwer, after whom the minor planet

1746 Brouwer 1746 Brouwer ( ''prov. designation'': ) is a Hilda asteroid from the outermost region of the asteroid belt, approximately 64 kilometers in diameter. It was discovered on 14 September 1963, by IU's Indiana Asteroid Program at Goethe Link Observat ...

is named. At

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

, Schilt's research included the dynamics and structure of galaxies, and improvements in measuring the brightness of stars. The official naming citation was published by 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. Function ...

on 11 December 1981 ().

Orbit and classification

Physical characteristics

Rotation period

Diameter and albedo

Naming

Notes

References

External links