2429 Schürer, provisional designation , is a Maria asteroid from the central region of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...

, approximately in diameter. It was discovered on 12 October 1977, by Swiss astronomer Paul Wild at

Zimmerwald Observatory The Zimmerwald Observatory (german: Observatorium Zimmerwald) is an astronomical observatory owned and operated by the AIUB, the Astronomical Institute of the University of Bern. Built in 1956, it is located at Zimmerwald, 10 kilometers south of B ...

near Bern, Switzerland, and later named after Swiss astronomer Max Schürer. The likely elongated

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 ...

has a

rotation period The rotation period of a celestial object (e.g., star, gas giant, planet, moon, asteroid) may refer to its sidereal rotation period, i.e. the time that the object takes to complete a single revolution around its axis of rotation relative to the ...

of 6.6 hours.

Orbit and classification

''Schürer'' is a member of the

Maria family The Maria family (adj. ''Marian''; FIN: 506; also known as ''Roma family'') is a collisional asteroid family located in the inner parts of the intermediate asteroid belt, near the 1:3 Kirkwood gap. The family consist of several thousand stony S-ty ...

(

506 Year 506 (Roman numerals, DVI) was a common year starting on Sunday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Flavius Ennodius Messala, Messala and Areobindus Dagalai ...

), a large

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of stony asteroids with nearly 3000 known members, named after asteroid 170 Maria. The family is old, about years, and located near the 3:1 resonant region with Jupiter that supplies

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

s to the inner

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

. It is estimated that every 100 million years, about 37 to 75 Maria asteroids larger than 1 kilometer become such near-Earth objects. 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 2.3–2.8 AU once every 4 years and 1 month (1,507 days;

semi-major axis In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the long ...

of 2.57 AU). 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-center, in geometry * Eccentricity (graph theory) of a v ...

of 0.10 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 15 ° with respect to the

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...

. 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 a

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 ...

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 October 1915, or 62 years prior to its official discovery observation at

Zimmerwald Zimmerwald was an independent municipality in the Canton of Bern, Switzerland until 31 December 2003. It is located on a hill in the proximity of the city of Bern in the Bernese Mittelland. On 1 January 2004 Zimmerwald united with the municipality ...

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 in honor of Swiss astronomer Max Schürer (1910–1997), who was director of the Astronomical Institute of the

University of Bern The University of Bern (german: Universität Bern, french: Université de Berne, la, Universitas Bernensis) is a university in the Switzerland, Swiss capital of Bern and was founded in 1834. It is regulated and financed by the Canton of Bern. It ...

from 1947 to 1980. Due to his initiative, endurance, and great technical competence, the discovering observatory at Zimmerwald – after which the asteroid 1775 Zimmerwald is named – could be built in 1956. He did a lot of orbit computation on asteroids when he was a pupil of astronomer Sigmund Mauderli (1876–1962), who was the preceding director of the Astronomical Institute ''(also see 1748 Mauderli)''. Schürer also dealt with stellar dynamics and was deeply involved as a pioneer in

satellite geodesy Satellite geodesy is geodesy by means of artificial satellites—the measurement of the form and dimensions of Earth, the location of objects on its surface and the figure of the Earth's gravity field by means of artificial satellite techniques. ...

. The official 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 10 November 1992 ().

Physical characteristics

''Schürer'' is an assumed

, and corresponds to the overall stony

spectral type In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

of the Maria family.

Rotation period

In February 2012, a rotational

lightcurve In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...

of ''Schürer'' was obtained from photometric observations by an international collaboration under the lead of South Korean astronomers. Lightcurve analysis gave a

of hours with a brightness amplitude of 0.77

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 ...

, indicative of an elongated, non-spherical shape (). A modeled lightcurve using photometric data from ''Gaias'' DR2 catalog was published in 2018. It gave a similar sidereal period of hours, as well as a

spin axis Rotation around a fixed axis is a special case of rotational motion. The fixed-axis hypothesis excludes the possibility of an axis changing its orientation and cannot describe such phenomena as wobbling or precession. According to Euler's rot ...

at (235.0°, −26.0°) in

ecliptic coordinates The ecliptic coordinate system is a celestial coordinate system commonly used for representing the apparent positions, orbits, and pole orientations of Solar System objects. Because most planets (except Mercury) and many small Solar System bodi ...

(λ, β).

Diameter and albedo

According to the surveys carried out by the

NEOWISE 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, ...

mission of 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, ...

, ''Schürer'' measures between 11.58 and 16.0 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 ...

between 0.096 and 0.229. while the Japanese Akari satellite gives a diameter of 15.95 km with a low albedo of 0.096. The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.21 and calculates a diameter of 11.55 kilometers based on an

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

of 12.0.

References

Historical Dictionary of Switzerland The ''Historical Dictionary of Switzerland'' is an encyclopedia on the history of Switzerland that aims to take into account the results of modern historical research in a manner accessible to a broader audience. The encyclopedia is publishe ...