1158 Luda, 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 ...

from the middle regions of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

, approximately 19 kilometers in diameter. It was discovered on 31 August 1929, by Soviet astronomer

Grigory Neujmin Grigory Nikolayevich Neujmin (; – 17 December 1946) was a Georgian–Russian astronomer, native of Tbilisi in Georgia (country), Georgia, and a discoverer of numerous minor planets as well as 6 periodic comet, periodic and a List of hyperbolic ...

Simeiz Observatory Simeiz Observatory (also spelled Simeis or Simeïs) was an astronomy research observatory until the mid-1950s. It is located on Mount Koshka, Crimea, by the town of Simeiz. Part of the Crimean Astrophysical Observatory, it is currently used fo ...

on the Crimean peninsula. It was named after Ludmilla Neujmin, the sister of the discoverer.

Orbit and classification

''Luda'' orbits the Sun at a distance of 2.3–2.9 AU once every 4 years and 1 month (1,499 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 0.11 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 first used observation at Johannesburg Observatory, one month after its official discovery observation at Simeiz. ''Luda'' is a stony S-type asteroid. Based on its orbital elements, ''Luda'' is a member of the Eunomia family, a large group of stony asteroids and the most prominent family in the intermediate main-belt, while Argentine astronomer Alvarez-Candal from the Universidad Nacional de Córdoba groups it into the smaller Maria family, which is named after 170 Maria (the same discrepancy exists for 9175 Graun and 2429 Schürer).

Physical characteristics

Photometry

Several 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 ...

s of ''Luda'' were obtained from photometric observations. Analysis of the best-rated lightcurves obtained by French amateur astronomer Laurent Bernasconi, American astronomer Brian Warner, and an international group led by Korean astronomers, gave a well-defined

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 ...

between 6.86 and 6.87 hours with a brightness variation between 0.13 and 0.22

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 ...

(). Photometric observations also gave a period of 6.9 and 7.44 hours, but these were derived from a fragmentary and ambiguous light curve, respectively.().

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite

IRAS The Infrared Astronomical Satellite (Dutch language, Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a astronomical survey, survey of the entire night sky at infrared wavelengths. Launched on 25 Janu ...

, the Japanese Akari satellite, and NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

with its subsequent

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission, ''Luda'' measures between 18.63 and 20.59 kilometers in diameter and its surface has an

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 ...

between 0.20 and 0.25. The ''Collaborative Asteroid Lightcurve Link'' adopts the results obtained by IRAS, that is, an albedo of 0.232 and a diameter of 19.06 kilometers with an absolute magnitude of 10.8.

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 for Ludmilla Neujmin, the sister of the discoverer. "Luda" is a diminutive of Ludmilla. Astronomer Lutz Schmadel, who compiled this naming citation, based it on a private communication with "N. S. Samojlova-Yakhontova", as neither the

Minor Planet Circulars 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. Functio ...

nor '' The Names of the Minor Planets'' give any information about this asteroid's name.

References

External links

Lightcurve plot of 1158 Luda
Palmer Divide Observatory, '' B. D. Warner'' (1999)
Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Luda 001158 001158 Discoveries by Grigory Neujmin Named minor planets 001158 19290831