1257 Móra, provisional designation , is an
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 inner 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 15 kilometers in diameter. It was discovered on 8 August 1932, by German astronomer
Karl Reinmuth at
Heidelberg Observatory in southwest Germany.
The asteroid was named after Hungarian astronomer .
Orbit and classification
''Móra'' orbits the Sun in the
inner main-belt at a distance of 2.3–2.7
AU once every 3 years and 11 months (1,434 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 0.08 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 ...
.
Identified as , it was first observed at Heidelberg and
Algiers Observatory in 1928, extending the body's
observation arc by 4 years prior to its official discovery observation.
Physical characteristics
Rotation period
American astronomer
Richard Binzel and French amateur astronomer
René Roy obtained three rotational
light curve
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 ''Móra'' from photometric observation taken in 1983 and 2009/11, respectively. Light curve analysis 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 2.28 and 2.30 hours with a change in brightness of 0.23 to 0.43
magnitude ().
The short period is just above the threshold of 2.2 hours for the so-called
fast rotators.
Diameter, albedo and spectral type
According to the space-based 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, ''Móra'' measures between 14.72 and 21.47 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 0.051 and 0.10.
The ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for stony
S-type asteroids of 0.20 and derives a shorter diameter of 10.79 kilometers,
while Richard Binzel classified it as a carbonaceous
C-type asteroid
C-type (carbonaceous ) asteroids are the most common variety, forming around 75% of known asteroids. They are volatile-rich and distinguished by a very low albedo because their composition includes a large amount of carbon, in addition to rocks ...
during his photometric observations in the 1980s.
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 in honour of Hungarian astronomer Károly Móra (1899–1938). The official naming citation was mentioned in ''
The Names of the Minor Planets'' by
Paul Herget in 1955 (). As a curiosity, astronomer
Paul Wild reshuffled the letters and numbers of the designation "1257 Mora" to construct a name for his discovery
2517 Orma in 1968 (' also means "trace, track" in Italian).
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:Mora
001257
Discoveries by Karl Wilhelm Reinmuth
Named minor planets
19320808