2006 Polonskaya (''
provisional designation
Provisional designation in astronomy is the naming convention applied to astronomical objects immediately following their discovery. The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...
'': ) is a stony
Flora asteroid and asynchronous
binary system
A binary system is a system of two astronomical bodies which are close enough that their gravitational attraction causes them to orbit each other around a barycenter ''(also see animated examples)''. More restrictive definitions require that th ...
from the inner regions of the
asteroid belt
The asteroid belt is a torus-shaped region in the Solar System, located roughly between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies, of many sizes, but much smaller than planets, called ...
, approximately in diameter. It was discovered on 22 September 1973, by Soviet astronomer
Nikolai Chernykh
Nikolai Stepanovich Chernykh (russian: Никола́й Степа́нович Черны́х) (6 October 1931 – 25 May 2004Казакова, Р.К. Памяти Николая Степановича Черных'. Труды Государст ...
at the
Crimean Astrophysical Observatory
The Crimean Astrophysical Observatory (CrAO, List of observatory codes, obs. code: IAU code#095, 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called ...
in Nauchnij, on the Crimean peninsula, and later named after Ukrainian astronomer
Elena Kazimirtchak-Polonskaïa
Olena Ivanivna Kazymyrchak-Polonska (21 November 1902 – 30 August 1992) was a Ukrainian astronomer and member of the International Astronomical Union, who studied the motion of comets and their orbital evolution. Asteroid 2006 Polonskaya ...
.
Its one-kilometer-sized
satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...
was discovered by an international collaboration of astronomers in November 2005.
Classification and orbit
''Polonskaya'' is a member of the
Flora family
The Flora family (''adj. Florian''; ; also known as ''Ariadne family'') is a prominent family of stony asteroids located in the inner region of the asteroid belt. It is one of the largest families with more than 13,000 known members, or approx ...
, one of the largest collisional populations of
stony asteroids, when applying the synthetic
hierarchical clustering method
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 ...
(HCM) by
Nesvorný.
However, according to another HCM-analysis by
Milani Milani (or Milāni) is an Italian surname. Notable people with the surname include:
*Abbas Milani (born 1949), Iranian-American historian and author
*Alfredo Milani (born 1924), Italian motorcycle racer
*Andrea Milani, several people
** Andrea Mila ...
and
Knežević (AstDys), it is a
background asteroid
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 ...
as in this analysis the Flora
asteroid clan is not recognized.
''Polonskaya'' orbits the Sun in the
inner
Interior may refer to:
Arts and media
* ''Interior'' (Degas) (also known as ''The Rape''), painting by Edgar Degas
* ''Interior'' (play), 1895 play by Belgian playwright Maurice Maeterlinck
* ''The Interior'' (novel), by Lisa See
* Interior de ...
main-belt at a distance of 1.9–2.8
AU once every 3 years and 7 months (1,295 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 2.32 AU). 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-center, in geometry
* Eccentricity (graph theory) of a v ...
of 0.19 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 Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...
of 5
° with respect to the
ecliptic
The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...
.
On 16 September 1941, it was first observed at the Finnish
Turku Observatory
Turku ( ; ; sv, Åbo, ) is a city and former capital on the southwest coast of Finland at the mouth of the Aura River, in the region of Finland Proper (''Varsinais-Suomi'') and the former Turku and Pori Province (''Turun ja Porin lääni''; ...
in Finland. 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 in April 1950 at
Palomar Mountain
Palomar Mountain ( ; es, Monte Palomar ) is a mountain ridge in the Peninsular Ranges in northern San Diego County. It is famous as the location of the Palomar Observatory and Hale Telescope, and known for the Palomar Mountain State Park.
Hist ...
, about 23 years prior to its official discovery observation.
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 after Russian astronomer Elena Ivanovna Kazimirchak-Polonskaya (1902–1992), who researched the motion and orbital evolution of
comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
s, in particular the capture of comets by major planets. She was a member of
IAU
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...
's Commission XX, and was awarded the
F. A. Bredikhin prize.
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.
Function
...
on 1 September 1978 ().
Satellite
In 2005, it was claimed that
lightcurve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...
observations indicate that ''Polonskaya'' has a small
moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
about 0.99 km in diameter.
However, the non-synchronously rotating binary still needs to be fully resolved in order to confirm such satellite. Alternatively, the presence of another body has also been suggested to explain the lightcurve's irregular period, which would make it a
trinary asteroid
A minor-planet moon is an astronomical object that orbits a minor planet as its natural satellite. , there are 457 minor planets known or suspected to have moons. Discoveries of minor-planet moons (and binary objects, in general) are important ...
.
Physical characteristics
''Polonskaya'' is considered a stony
S-type asteroid
S-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 of this type, making it the second ...
with a typically high
albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body ...
due to its membership to the
Flora family
The Flora family (''adj. Florian''; ; also known as ''Ariadne family'') is a prominent family of stony asteroids located in the inner region of the asteroid belt. It is one of the largest families with more than 13,000 known members, or approx ...
.
Lightcurves
Between 2005 and 2010, several rotational
lightcurve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequ ...
s of ''Polonskaya'' were obtained from
photometric observations by
Donald Pray,
Petr Pravec
Petr Pravec (born September 17, 1967) is a Czech astronomer and a discoverer of minor planets, born in Třinec, Czech Republic.
Pravec is a prolific discoverer of binary asteroids, expert in photometric observations and rotational lightcurves a ...
,
Peter Kušnirák
Peter Kušnirák (born 1974) is a Slovakia, Slovak astronomer, discoverer of minor planets, and a prolific Photometry (astronomy), photometrist of light-curves at Ondřejov Observatory in the Czech Republic. He was married to Slovak astronomer Ulr ...
,
Walter Cooney,
John Gross and Dirk Terrell. Lightcurve analysis gave a
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 ...
between 3.114 and 3.1183 hours with a brightness amplitude of 0.18–0.10
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 ...
for the best rated results ().
A later retracted alternative period solution of (about twice as long) has also been proposed.
In September 2019, follow-up observations by Pravec gave an unchanged rotation period of ().
Diameter and albedo
According to the survey carried out by NASA's
Wide-field Infrared Survey Explorer
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
with its subsequent
NEOWISE
Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and SMEX-6) is a NASA infrared astronomy space telescope in the Explorers Program. It was launched in December 2009, and placed in hibernation mode in February 2011, ...
mission, ''Polonskaya'' measures 4.625 kilometers in diameter and its surface has an albedo of 0.354.
The ''Collaborative Asteroid Lightcurve Link'' adopts
Petr Pravec
Petr Pravec (born September 17, 1967) is a Czech astronomer and a discoverer of minor planets, born in Třinec, Czech Republic.
Pravec is a prolific discoverer of binary asteroids, expert in photometric observations and rotational lightcurves a ...
's revised WISE-data, that is, an albedo of 0.3498 and a diameter of 4.80 kilometers based on an
absolute magnitude
Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...
of 13.35.
References
External links
Asteroids with Satellites Robert Johnston, johnstonsarchive.net
Asteroid Lightcurve Database (LCDB) query form
)
Dictionary of Minor Planet Names Google books
– Geneva Observatory,
Raoul Behrend
This is a list of minor-planet discoverers credited by the Minor Planet Center with the discovery of one or several minor planets (such as near-Earth and main-belt asteroids, Jupiter trojans and distant objects). , the discovery of 612,011 num ...
Discovery Circumstances: Numbered Minor Planets (1)-(5000)– Minor Planet Center
*
*
{{DEFAULTSORT:Polonskaya
002006
Discoveries by Nikolai Chernykh
Named minor planets
002006
19730922
20051101