6398 Timhunter, provisional designation , is a stony Phocaea
asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere.
...
from the inner regions of the
asteroid belt, approximately 5.5 kilometers in diameter. It was discovered on 10 February 1991, by American astronomer couple
Carolyn
Carolyn is a female given name, a variant of Caroline. Other spellings include Karolyn, Carolyne, Carolynn or Carolynne. Caroline itself is one of the feminine forms of Charles.
List of Notable People
*Carolyn Bennett (born 1950), Canadian pol ...
and
Eugene Shoemaker, in collaboration with Canadian astronomer
David H. Levy
David Howard Levy (born May 22, 1948) is a Canadian amateur astronomer, science writer and discoverer of comets and minor planets, who co-discovered Comet Shoemaker–Levy 9 in 1993, which collided with the planet Jupiter in 1994.
Biography
L ...
at
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, United States.
It was named for American amateur astronomer
Tim Hunter.
Classification an orbit
The 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 ...
is a member of the
Phocaea family The Phocaea family ( ; adj. ''Phocaean''; ) is a collisional family of asteroids located between 2.25 and 2.5 AU in the inner region of the asteroid belt. Phocaea asteroids are of stony S-type composition and have orbits with eccentricities ...
(),
a relatively small group of asteroids with similar orbital characteristics. ''Timhunter'' 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 1.8–2.9
AU once every 3 years and 7 months (1,310 days). Its orbit has an
eccentricity of 0.22 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 24
° with respect to the
ecliptic.
It was first identified as at
Goethe Link Observatory
The Goethe Link Observatory, observatory code 760, is an astronomical observatory near Brooklyn, Indiana, United States. It is owned by Indiana University and operated by the Indiana Astronomical Society https://iasindy.org/about.html, which eff ...
in 1955, extending 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 ...
by 36 years prior to its official discovery observation at Palomar.
Lightcurves
In March 2009, a rotational
lightcurve of ''Timhunter'' was obtained from photometric observations by 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 ...
at the
Ondřejov Observatory
The Ondřejov Observatory (; cs, Observatoř Ondřejov) is the principal observatory of the Astronomical Institute () of the Academy of Sciences of the Czech Republic. It is located near the village of Ondřejov, southeast of Prague, Czech R ...
in the Czech Republic. Lightcurve analysis gave a well-defined
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 14.55 hours with a brightness variation of 0.29
magnitude (). One month later, another lightcurve was obtained by French amateur astronomers
David Romeuf
David (; , "beloved one") (traditional spelling), , ''Dāwūd''; grc-koi, Δαυΐδ, Dauíd; la, Davidus, David; gez , ዳዊት, ''Dawit''; xcl, Դաւիթ, ''Dawitʿ''; cu, Давíдъ, ''Davidŭ''; possibly meaning "beloved one". w ...
, Maurice Audejean and
René Roy, which gave an alternative period solution of 7.1074 hours with an amplitude of 0.32 magnitude ().
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 mission, ''Timhunter'' measures 5.20 and 5.528 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 ...
of 0.333 and 0.27. respectively.
The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.23 – derived from
25 Phocaea
Phocaea (minor planet designation: 25 Phocaea) is a stony asteroid from the inner regions of the asteroid belt, approximately 75 kilometers in diameter. It is the parent body of the Phocaea family. Discovered by Jean Chacornac in 1853, it was n ...
, the Phocaea family's namesake – and calculates a diameter of 5.79 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 13.4.
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
Tim Hunter, an American radiologist and amateur astronomer. Together with
David Crawford he co-founded the non-profit
International Dark-Sky Association
The International Dark-Sky Association (IDA) is a United States-based non-profit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician/amateur astronomer. The mission of the IDA is " ...
with the aim to preserve and protect Earth's night sky from light pollution.
The approved 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 1 June 1996 ().
Notes
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:Timhunter
006398
Discoveries by Carolyn S. Shoemaker
Discoveries by Eugene Merle Shoemaker
Discoveries by David H. Levy
Named minor planets
19910210