5542 Moffatt, provisional designation , is a Marian

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 central regions of the asteroid belt, approximately in diameter. It was discovered on 6 August 1978, by astronomers at the Perth Observatory in Bickley, Australia. The likely

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 ...

has 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 ...

of 5.19 hours. It was named for Australian Ethelwin Moffatt, a benefactor of the discovering observatory.

Orbit and classification

''Moffatt'' is a core member of the

Maria family The Maria family (adj. ''Marian''; FIN: 506; also known as ''Roma family'') is a collisional asteroid family located in the inner parts of the intermediate asteroid belt, near the 1:3 Kirkwood gap. The family consist of several thousand stony S-ty ...

(), a large intermediate belt

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 asteroids. Alternatively, it has also been assigned to the stony

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 ...

(), one of the most prominent families 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 ...

main-belt at a distance of 2.2–3.0 AU once every 4 years and 2 months (1,520 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 2.59 AU). Its orbit has an eccentricity 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 Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 16 ° 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 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 July 1978, a month prior to its official discovery observation at Bickley.

Physical characteristics

''Moffatt'' is an assumed stony

Rotation period

In November 2011, a rotational lightcurve of ''Moffatt'' was obtained from photometric observations by Chinese astronomers using the SARA telescopes of the Southeastern Association for Research in Astronomy at

Kitt Peak Kitt Peak ( ood, Ioligam) is a mountain in the U.S. state of Arizona, and at is the highest point in the Quinlan Mountains. It is the location of the Kitt Peak National Observatory. The radio telescope at the observatory is one of ten dishes co ...

and

CTIO The Cerro Tololo Inter-American Observatory (CTIO) is an astronomical observatory located on Cerro Tololo in the Coquimbo Region of northern Chile, with additional facilities located on Cerro Pachón about to the southeast. It is approximately ...

. Lightcurve analysis gave a

of 5.187 hours and a brightness variation of 0.12 magnitude (). This supersedes a previous result from a fragmentary lightcurve by that gave a period of 5.195 hours with an amplitude of 0.27 magnitude ().

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, ...

, ''Moffatt'' measures 8.597 kilometers in diameter and its surface has a 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 ...

of 0.345. The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.21 – derived from

15 Eunomia Eunomia (minor planet designation 15 Eunomia) is a very large asteroid in the inner asteroid belt. It is the largest of the stony ( S-type) asteroids, with 3 Juno as a close second. It is quite a massive asteroid, in 6th to 8th place (to within ...

, the parent body of the Eunomia family – and calculates a diameter of 10.06 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 12.3.

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 Australian Ethelwin Moffatt (née Winzar, born 1926), a benefactor of the discovering Perth Observatory and a direct descendant of John Flamsteed (1646–1719), the first Astronomer Royal. 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 2 September 2001 ().

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Minor Planet Center * * {{DEFAULTSORT:Moffatt 005542 005542 Named minor planets 19780806