1112 Polonia, provisional designation , is an
Eoan asteroid from the outer regions of the
asteroid belt, approximately in diameter. Discovered by Soviet astronomer
Pelageya Shajn at
Simeiz
Simeiz ( uk, Сімеїз, russian: Симеи́з, crh, Simeiz) is a resort town, an urban-type settlement in Yalta Municipality in the Autonomous Republic of Crimea, a territory recognized by a majority of countries as part of Ukraine and incorp ...
in 1928,
it was the first asteroid discovery made by a woman.
The
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 asteroid, K-type, they exhibit a more reddish spectrum at ...
has a long
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 82.5 hours,
and was named for the country of
Poland.
Discovery
''Polonia'' was first observed as at the German
Heidelberg Observatory in December 1908. It was officially discovered on 15 August 1928, by Soviet astronomer
Pelageya Shajn at the
Simeiz Observatory on the Crimean peninsula.
On the following night at Simeis, it was independently discovered by her college
Grigory Neujmin.
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.
Function
...
only recognized the first discoverer.
''Polonia'' was Shajn's first discovery; and the first asteroid discovery made by a woman,
bringing a long-standing tradition – which began with the discovery of
1 Ceres in 1801 – of more than a
thousand minor planet discoveries exclusively made by
male astronomers, to an end.
Orbit and classification
''Polonia'' is a core member of the
Eos family The Eos family (''adj. Eoan'' ; ) is a very large asteroid family located in the outer region of the asteroid belt. The family of K-type asteroids is believed to have formed as a result of an ancient catastrophic collision. The family's parent body ...
(),
the largest
asteroid family
An asteroid family is a population of asteroids that share similar proper orbital elements, such as semimajor axis, eccentricity, and orbital inclination. The members of the families are thought to be fragments of past asteroid collisions. An a ...
of the
outer main belt consisting of nearly 10,000 asteroids.
It orbits the Sun at a distance of 2.7–3.3
AU once every 5 years and 3 months (1,916 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 3.02 AU). Its orbit has an
eccentricity of 0.11 and an
inclination of 9
° with respect to the
ecliptic.
The body's
observation arc begins with its official discovery observation at Simeiz in 1928.
Physical characteristics
In the
Tholen classification, ''Polonia'' is a common, stony
S-type asteroid.
In the more refined
SDSS-based taxonomy, it is characterized as an uncommon
L-type,
which is similar to a
K-type, the overall
spectral type of the Eoan asteroids.
Rotation period
In October 2007, a rotational
lightcurve of ''Polonia'' was obtained from
photometric observations by American astronomer
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 long
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 82.5 hours with a brightness amplitude of 0.20
magnitude ().
The asteroid's long period it is close to that of a
slow rotator.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite
IRAS, the Japanese
Akari satellite and the
NEOWISE mission of NASA's
Wide-field Infrared Survey Explorer, ''Polonia'' measures between 35.76 and 47.058 kilometers in diameter and its surface has an
albedo between 0.0763 and 0.1319.
The ''Collaborative Asteroid Lightcurve Link'' adopts the results obtained by IRAS, that is, an albedo of 0.1319 and a diameter of 35.76 kilometers based on an
absolute magnitude of 10.05.
Naming
This
minor planet was named "Polonia", the
Latin name for the European country of
Poland. It is the first minor planet discovery made by a woman. The naming was proposed by L. Matkiewicz, an astronomer of Polish origin, who calculated the body's orbit. The official citation was mentioned in ''
The Names of the Minor Planets'' by
Paul Herget in 1955 ().
Notes
References
External links
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Minor Planet Center
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{{DEFAULTSORT:Polonia
001112
Discoveries by Pelageya Shajn
Named minor planets
001112
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