1215 Boyer, provisional designation , is a stony Eunomian
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 central region 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 20 kilometers in diameter. It was discovered by astronomer
Alfred Schmitt in 1932, who named it after French astronomer and college
Louis Boyer.
Discovery
''Boyer'' was discovered on 19 January 1932, by French astronomer
Alfred Schmitt at the
Algiers Observatory in Algeria, North Africa.
Eight days later, it was independently discovered by
Karl Reinmuth at
Heidelberg Observatory in Germany.
The body's
observation arc begins at Algiers with its official discovery observation.
Classification and orbit
''Boyer'' is a member of the
Eunomia family (), the most prominent family in the
intermediate main-belt, which mostly consists of stony asteroids. Conversely, ''Boyer'' has also been grouped into the
Maria family ().
It orbits the Sun at a distance of 2.2–2.9
AU once every 4 years and 2 months (1,512 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 0.13 and an
inclination of 16
° 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
Tholen classification, ''Boyer'' is a common, stony
S-type asteroid.
Lightcurves
In August 2008 and May 2012, two 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 ''Boyer'' were obtained from photometric observations by an international collaboration of astronomers studying the rotational properties of Maria asteroids, using the ground-based
Wise Observatory
The Florence and George Wise Observatory (IAU code 097) is an astronomy, astronomical observatory owned and operated by Tel Aviv University. It is located west of the town of Mitzpe Ramon in the Negev desert near the edge of the Ramon Crater, an ...
in Israel. Lightcurve analysis gave a
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 10.36 hours with a brightness variation of 0.31 and 050
magnitude, respectively ().
Diameter and albedo
According to the surveys carried out by 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 mission, ''Boyer'' measures between 13.041 and 24.65 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 0.116 and 0.3012.
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.21, derived from the Eunomia family's largest member and namesake,
15 Eunomia, and calculates a diameter of 17.47 kilometers with an
absolute magnitude of 11.1.
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 by the discoverer after his colleague at Algiers Observatory,
Louis Boyer (1901–1999), who worked extensively on asteroids and
comet
A comet is an icy, small Solar System body that warms and begins to release gases when passing close to the Sun, a process called outgassing. This produces an extended, gravitationally unbound atmosphere or Coma (cometary), coma surrounding ...
s. Boyer himself was a
discoverer of minor planets at Algiers. He later worked on identifications at
Nice observatory.
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.
Funct ...
on 1 August 1978 ().
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:Boyer
001215
Discoveries by Alfred Schmitt
Named minor planets
001215
19320119