79912 Terrell (

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 The provisional designation is usually superseded by a permanent designation once a reliable orbit has been calcu ...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 dark Adeonian

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 central 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 6 kilometers in diameter. It was discovered on 10 February 1999, by astronomers Walter Cooney and Ethan Kandler at the

Highland Road Park Observatory Highland Road Park Observatory or Baton Rouge Observatory is an astronomy, astronomical observatory jointly operated by Louisiana State University's astronomy department, Baton Rouge Astronomical Society, and The Recreation & Park Commission for t ...

, in Baton Rouge, Louisiana, United States. The asteroid was named after American astrophysicist

Dirk Terrell Dirk Terrell (born August 14, 1965) is an American astronomer and space artist who is the Director of the Computer and Software Sciences section in the Planetary Science Directorate of the Space Science and Engineering division of the Southwest R ...

Orbit and classification

Terrell is a member of the

Adeona family The Adeona or Adeonian family () is a large asteroid family that formed from the parent body 145 Adeona. Its spectral type is that of a carbonaceous C-type, with currently 2,236 asteroids identified as family members. Based upon simulation A s ...

(), a large

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

carbon Carbon () is a chemical element; it has chemical symbol, symbol C and atomic number 6. It is nonmetallic and tetravalence, tetravalent—meaning that its atoms are able to form up to four covalent bonds due to its valence shell exhibiting 4 ...

aceous asteroids in the central main belt, named after 145 Adeona. It orbits the Sun at a distance of 2.2–3.1 AU once every 4 years and 5 months (1,599 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 0.16 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 11 ° 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 ...

. 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 identification as by

AMOS Amos or AMOS may refer to: Arts and entertainment * ''Amos'' (album), an album by Michael Ray * Amos (band), an American Christian rock band * ''Amos'' (film), a 1985 American made-for-television drama film * Amos (guitar), a 1958 Gibson Fl ...

at Haleakala Observatory in August 1996, more than two years prior to its official discovery observation at

Baton Rouge Baton Rouge ( ; , ) is the List of capitals in the United States, capital city of the U.S. state of Louisiana. It had a population of 227,470 at the 2020 United States census, making it List of municipalities in Louisiana, Louisiana's second-m ...

Physical characteristics

The asteroid's

spectral type In astronomy, stellar classification is the classification of stars based on their spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a prism or diffraction grating into a spectrum exhibiting the ...

is unknown. Members of the

are typically carbonaceous

C-type asteroids 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 ...

, which Terrell's albedo agrees with.

Diameter and albedo

According to the survey carried out by the

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission of 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 ...

, Terrell measures 6.340 kilometers in diameter and its surface has a low

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 ...

of 0.053.

Rotation period

As of 2017, no rotational

lightcurve 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 ...

of Terrell has been obtained from photometric observations. The asteroid's

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 ...

, poles and shape remain unknown.

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 American

(born 1965), an astrophysicist, writer,

space art Space art, also known as astronomical art, is a genre of art that Visual representation, visually depicts the universe through various Style (visual arts), artistic styles. It may also refer to Work of art, artworks sent into Outer space, space. ...

ist, and mentor of

amateur astronomer Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers m ...

s. 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. Funct ...

on 18 September 2005 ().

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:Terrell 079912 Discoveries by Walter R. Cooney Jr. Discoveries by Ethan Kandler Named minor planets 19990210