873 Mechthild ( ''prov. designation'': ''or'' ) is a dark background asteroid from the central regions of the asteroid belt. It was discovered by German astronomer

Max Wolf Maximilian Franz Joseph Cornelius Wolf (21 June 1863 – 3 October 1932) was a German astronomer and a pioneer in the field of astrophotography. He was the chairman of astronomy at the University of Heidelberg and director of the Heidelberg-K� ...

at the Heidelberg Observatory on 21 May 1917. The primitive P-type asteroid 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 11.0 hours and measures approximately in diameter. The origin of the asteroid's name remains unknown.

Orbit and classification

''Mechthild'' is a non- family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. 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 ...

asteroid belt at a distance of 2.2–3.0 AU once every 4 years and 3 months (1,555 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 2.63 AU). Its orbit has an eccentricity of 0.15 and an inclination of 5 ° with respect to the ecliptic. The body's observation arc begins with its first and official discovery observation at Heidelberg Observatory on 21 May 1917.

Naming

This minor planet is named " Mechthild", a German feminine given name. Any reference of this name to a specific person or occurrence is unknown.

Unknown meaning

Among the many thousands of

named minor planets Named may refer to something that has been given a name. Named may also refer to: * named (computing), a widely used DNS server * Naming (parliamentary procedure) * The Named (band), an American industrial metal group In literature: * ''The Na ...

, ''Mechthild'' is one of 120 asteroids, for which no official naming citation has been published. All of these low-numbered asteroids have numbers between and and were discovered between 1876 and the 1930s, predominantly by astronomers Auguste Charlois,

Johann Palisa Johann Palisa (6 December 1848 – 2 May 1925) was an Austrian astronomer, born in Troppau, Austrian Silesia, now Czech Republic. He was a prolific discoverer of asteroids, discovering 122 in all, from 136 Austria in 1874 to 1073 Gel ...

and Karl Reinmuth.

Physical characteristics

In the Tholen classification, ''Mechthild'' is closest to a very dark, primitive P-type, and somewhat similar to a common C-type asteroid. In the taxonomy by Barucci, it is a C0-type. P-type asteroids are more common in the outer asteroid belt and among the

Jupiter trojan The Jupiter trojans, commonly called trojan asteroids or simply trojans, are a large group of asteroids that share the planet Jupiter's orbit around the Sun. Relative to Jupiter, each trojan librates around one of Jupiter's stable Lagrange poin ...

population.

Rotation period

In May 2015, a rotational lightcurve of ''Mechthild'' was obtained from photometric observations by Brian Warner at his

Palmer Divide Observatory This is a list of observatory codes (IAU codes or MPC codes) published by the Minor Planet Center. For a detailed description, ''see observations of small Solar System bodies Observations of minor planets as well as comets and natural satellite ...

in Colorado. Lightcurve analysis gave a

of hours with a brightness amplitude of magnitude (). Alternative period determinations were made by Claes-Ingvar Lagerkvist () in March 1976, by astronomers at the

Palomar Transient Factory The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...

() in January 2014, and by the Spanish group of asteroid observers, OBAS () in May 2015 (). In 2016, a modeled lightcurve gave a concurring sidereal period of hours using data from a large collaboration of individual observers (such as above). The study also determined two spin axes of (249.0°, −52.0°) and (51.0°, −61.0°) in ecliptic coordinates (λ, β).

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, and the Japanese Akari satellite, and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer (WISE), ''Mechthild'' measures (), () and () kilometers in diameter and its surface has an albedo of (), () and (), respectively. The ''Collaborative Asteroid Lightcurve Link'' adopts the results from IRAS, that is, an albedo of 0.0531 and a diameter of 29.04 kilometers based on an absolute magnitude of 11.49. Alternative mean-diameter measurements published by the WISE team include () and () with corresponding albedos of () and ().

References

External links

Lightcurve Database Query
(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names
Google books

– Minor Planet Center * * {{DEFAULTSORT:Mechthild 000873 Discoveries by Max Wolf Named minor planets 000873 19170521