9983 Rickfienberg ( ''prov. designation'': ) is a carbonaceous

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 middle region of the asteroid belt, approximately in diameter. It was discovered on 19 February 1995, by American astronomer

Dennis di Cicco Dennis di Cicco (born 1950) is an American amateur astronomer and a discoverer of minor planets, who lives in New England. He has discovered 60 numbered asteroids from his backyard observatory in Sudbury, Massachusetts (IAU code: 817). He was ...

at his private Sudbury Observatory , Massachusetts, United States. It was named after American astronomer and editor Richard Fienberg.

Orbit and classification

''Rickfienberg'' 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 ...

. The dark C-type asteroid 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 ...

main-belt at a distance of 2.4–3.0 AU once every 4 years and 5 months (1,627 days). Its orbit has an eccentricity of 0.12 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 8 ° with respect to the ecliptic. The first observation was taken at the Australian

Siding Spring Observatory Siding Spring Observatory near Coonabarabran, New South Wales, Australia, part of the Research School of Astronomy & Astrophysics (RSAA) at the Australian National University (ANU), incorporates the Anglo-Australian Telescope along with a coll ...

in 1987, extending the asteroid'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 8 years prior to its discovery.

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 for Richard Tresch Fienberg (born 1956) an American astronomer at Rice and Harvard universities, and a stargazer at his private observatory near Danbury, New Hampshire. He is also an editor of the American amateur astronomer magazine '' Sky & Telescope'', after which the minor planet 3243 Skytel is named. The 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 May 2003 ().

Physical characteristics

Lightcurve

During the asteroid's opposition in November 2011, a rotational lightcurve was obtained from photometric observations at Kitt Peak Observatory. It 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 hours with a high brightness variation of 1.3 in magnitude (), typically indicating a non-spheroidal shape. This period was also confirmed by remodeled data from the Lowell photometric database in March 2016.

Diameter and albedo

According to the survey carried out by 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, ...

, ''Rickfienberg'' measures 7.4 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 0.17, while the ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 12.2 kilometers, as the lower the body's albedo (reflectivity), the larger its diameter, at a constant absolute magnitude (brightness).

References

External links

Richard Tresch Fienberg
''Sky & Telescope'', 18 July 2006
My Place in the Dark
by Richard Tresch Fienberg, ''Sky & Telescope'',17 July 2006
Lightcurve Database Query
(LCDB), at ''www.minorplanet.info''
Dictionary of Minor Planet Names
Google books

– '' Geneva Observatory'', Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (5001)-(10000)
– Minor Planet Center * * {{DEFAULTSORT:Rickfienberg 009983 Discoveries by Dennis di Cicco Named minor planets 19950219