4804 Pasteur, provisional designation , is a carbonaceous background

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 central regions of the asteroid belt, approximately 20 kilometers in diameter. It was discovered on 2 December 1989, by Belgian astronomer Eric Elst at the

ESO The European Organisation for Astronomical Research in the Southern Hemisphere, commonly referred to as the European Southern Observatory (ESO), is an intergovernmental research organisation made up of 16 member states for ground-based ast ...

's La Silla Observatory in Chile. The asteroid was named after French chemist and microbiologist

Louis Pasteur Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...

Orbit and classification

''Pasteur'' is a non- family asteroid from the main belt's background population. It orbits the Sun in the intermediate asteroid belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,612 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 2.69 AU). Its orbit has an eccentricity of 0.12 and an inclination of 9 ° with respect to the ecliptic. The body's observation arc 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

Palomar Observatory Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

in March 1956, more than 33 years prior to its official discovery observation.

Physical characteristics

In the

SMASS classification An asteroid spectral type is assigned to asteroids based on their emission spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally differentiat ...

, ''Pasteur'' is a C-type asteroid. Pan-STARRS photometric survey and SDSS–MFB (Masi–Foglia–Bus) have also characterized the body as a carbonaceous C-type.

Rotation period

In November 2011, a rotational lightcurve of ''Pasteur'' was obtained from photometric observations by astronomers at the Oakley Southern Sky Observatory in Australia. Lightcurve analysis gave a well-defined

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 13.69 hours with a brightness amplitude of 0.28 magnitude ().

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Pasteur'' measures between 15.427 and 21.38 kilometers in diameter and its surface has an albedo between 0.05 and 0.1290. The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.10 and calculates a diameter of 15.98 kilometers based on an absolute magnitude of 12.1.

Naming

This minor planet was named after French chemist and microbiologist

(1822–1895), who discovered the principles of vaccination,

fermentation Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In biochemistry, it is narrowly defined as the extraction of energy from carbohydrates in the absence of oxygen. In food ...

and

pasteurization Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life. The ...

. In 1888 the renowned Pasteur Institute was established in Paris. 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 21 November 1991 (). The lunar crater '' Pasteur'', as well as the Martian crater '' Pasteur'' have also been named after him.

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Pasteur 004804 Discoveries by Eric Walter Elst Named minor planets 004804 19891202