4790 Petrpravec (
''prov. designation'': ) is a carbonaceous
background asteroid from the central regions of the
asteroid belt, approximately in diameter. It was discovered on 9 August 1988, by American astronomer
Eleanor Helin
Eleanor Francis "Glo" Helin (née Francis, 19 November 1932 – 25 January 2009) was an American astronomer. She was principal investigator of the Near-Earth Asteroid Tracking (NEAT) program of NASA's Jet Propulsion Laboratory. (Some sources gi ...
at the
Palomar Observatory
Palomar Observatory is an astronomical research observatory in San Diego County, California, United States, in the Palomar Mountain Range. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...
in California, and later named for Czech astronomer
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 ...
.
Orbit and classification
''Petrpravec'' is a non-
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
asteroid of the main belt's
background population when applying the
hierarchical clustering method to its
proper orbital elements
__NOTOC__
The proper orbital elements or proper elements of an orbit are constants of motion of an object in space that remain practically unchanged over an astronomically long timescale. The term is usually used to describe the three quantitie ...
.
Based on osculating Keplerian
orbital elements
Orbital elements are the parameters required to uniquely identify a specific orbit. In celestial mechanics these elements are considered in two-body systems using a Kepler orbit. There are many different ways to mathematically describe the same ...
, the asteroid has also been classified as a member of the
Eunomia family The Eunomia or Eunomian family () is a large asteroid family of S-type asteroids named after the asteroid 15 Eunomia. It is the most prominent family in the intermediate asteroid belt and the 6th-largest family with nearly six thousand known members ...
(), a prominent
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
of 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 ...
and the largest one in the intermediate main belt with more than 5,000 members.
It orbits the Sun in the
central
Central is an adjective usually referring to being in the center of some place or (mathematical) object.
Central may also refer to:
Directions and generalised locations
* Central Africa, a region in the centre of Africa continent, also known as ...
asteroid belt at a distance of 2.4–2.9
AU once every 4 years and 3 months (1,554 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 2.63 AU). Its orbit has an
eccentricity of 0.09 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 13
° with respect to the
ecliptic.
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 with its first observation as ' at
Crimea–Nauchnij
The Crimean Astrophysical Observatory (CrAO, obs. code: 095) is located at Nauchnij research campus, near the Central Crimean city of Bakhchysarai, on the Crimean peninsula. CrAO is often called simply by its location and campus name, ...
in March 1978, more than 10 years prior to its official discovery observation at Palomar.
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
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 ...
(born 1967), a Czech astronomer and prolific
photometrist 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,
near-Earth and
binary asteroids. He has often been the first person to observe objects found in the course of the discoverer's
Near-Earth Asteroid Tracking program following their tentative announcement in 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
...
's (MPC) "NEO Confirmation Page". 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.
Function
...
on 20 June 1997 on the occasion of his marriage with Kateřina Macháčová the following day ().
Physical characteristics
In the
SDSS-based taxonomy, ''Petrpravec'' is a poorly determined, carbonaceous
C-type asteroid.
It has also been characterized as a dark C-type by
Pan-STARRS' survey.
Rotation period
A rotational
lightcurve of ''Petrpravec'' from
photometric observations at the
Oakley Southern Sky Observatory in February 2012, gave a brightness variation of only 0.02 magnitude and was insufficient to determine 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 ...
.
Diameter and albedo
According to the surveys carried out by the Japanese
Akari satellite, the
NEOWISE mission of 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, ...
and the Infrared Astronomical Satellite
IRAS
The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten mo ...
, ''Petrpravec'' measures between 14.4 and 17.6 kilometers in diameter and its surface has an
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 ...
between 0.0336 and 0.160.
The ''Collaborative Asteroid Lightcurve Link'' derives an albedo of 0.0369 and a diameter of 17.37 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 13.0.
References
External links
Lightcurve Database Query(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names Google books
– Minor Planet Center
*
*
{{DEFAULTSORT:Petrpravec
004790
Discoveries by Eleanor F. Helin
Named minor planets
19880809