2253 Espinette, 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 ...

and sizable

Mars-crosser A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for i ...

from the innermost 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 7 kilometers in diameter. Discovered by

George Van Biesbroeck George A. Van Biesbroeck (or Georges-Achille Van Biesbroeck, , January 21, 1880 – February 23, 1974) was a Belgian–American astronomer. He worked at observatories in Belgium, Germany and the United States. He specialized in the observation o ...

in 1932, the asteroid was named after the discoverer's residence "Espinette".

Discovery

''Espinette'' was discovered on 30 July 1932, by Belgian–American astronomer

at the U.S.

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 until 2018. O ...

, Wisconsin. The body was independently discovered on the following night by English-born South-African astronomer Cyril Jackson at Johannesburg, and by Soviet–Russian 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, on August 4. No

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

were taken. The asteroid'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 a few days after its official discovering observation.

Orbit and classification

The asteroid orbits the Sun in the inner main-belt at a distance of 1.6–2.9 AU once every 3 years and 5 months (1,260 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 0.28 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 4 ° 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 ...

Physical characteristics

In the SMASS taxonomic scheme, ''Espinette'' is classified as a Sl-subtype, which transitions from the common

S-type asteroid S-type (stony-type or silicaceous-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 ...

s to the much redder

L-type asteroid L-type asteroids are relatively uncommon asteroids with a strongly reddish spectrum shortwards of 0.75 μm, and a featureless flat spectrum longwards of this. In comparison with the K-type, they exhibit a more reddish spectrum at visible wavelen ...

Rotation period

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 ''Espinette'' have been obtained. In April 2011, photometric observations by American astronomer Brian A. Skiff rendered 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 ...

of hours with a brightness variation of 0.25

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 ...

(). In August 2015, another observation by

Robert Stephens Sir Robert Graham Stephens (14 July 193112 November 1995) was an English actor in the early years of Britain's Royal National Theatre. Early life Stephens was born in Shirehampton, Bristol, in 1931, the eldest of three children of shipyard ...

at the Center for Solar System Studies (), California, gave an identical period of with an amplitude of 0.44 magnitude (). Previous observations by Polish astronomer

Wiesław Z. Wiśniewski Wiesław Z. Wiśniewski (May 2, 1931 in Poland – February 28, 1994 in Tucson, Arizona, United States) was a Polish astronomer. Wisniewski was born and educated in Poland. He survived the Nazi occupation and many of his later insights and viewpo ...

in 1987, and by Italian Federico Manzini in 2005, rendered similar results ().

Diameter and albedo

The ''Collaborative Asteroid Lightcurve Link'' assumes a standard

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 ...

for stony asteroids of 0.20 and derives a diameter of 7.0 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 "Espinette" after the discoverer's U.S. home in

Williams Bay Williams Bay is a village in Walworth County, Wisconsin, United States. It is one of three municipalities on Geneva Lake. The population was 2,953 at the 2020 census. On June 22, 2024 the town was hit by an EF-1 tornado, there were no injurie ...

, Wisconsin, located near the discovering Yerkes Observatory. At their home, the Van Biesbroecks accommodated visitors of the observatory from all over the world. The name "Espinette" was proposed by the discoverer's children, and it refers to a coffeehouse in Belgium. 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. Funct ...

on 1 June 1981 ().

Notes

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:Espinette 002253 Discoveries by George Van Biesbroeck Named minor planets 002253 19320730