2061 Anza, provisional designation , is an eccentric

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 ...

of the Amor group, a subtype of

near-Earth object A near-Earth object (NEO) is any small Solar System body orbiting the Sun whose closest approach to the Sun ( perihelion) is less than 1.3 times the Earth–Sun distance (astronomical unit, AU). This definition applies to the object's orbit a ...

s, estimated to measure approximately 2.7 kilometers in diameter. It was discovered on 22 October 1960, by American astronomer Henry Giclas at Lowell's Flagstaff Observatory in Arizona, United States. The asteroid was later named after Spanish explorer

Juan Bautista de Anza Juan Bautista de Anza Bezerra Nieto (July 6 or 7, 1736 – December 19, 1788) was a Novohispanic/Mexican expeditionary leader, military officer, and politician primarily in California and New Mexico under the Spanish Empire. He is credited as on ...

Classification and orbit

''Anza'' is an

Amor asteroid The Amor asteroids are a group of near-Earth asteroids named after the archetype object 1221 Amor . The orbital perihelion of these objects is close to, but greater than, the orbital aphelion of Earth (i.e., the objects do not cross Earth's orbit ...

– a subgroup of near-Earth asteroids that approach the orbit of Earth from beyond, but do not cross it. Orbiting the Sun at a distance of 1.1–3.5 AU once every 3 years and 5 months (1,247 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 0.54 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 4 ° 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 ...

. Due to its high eccentricity, ''Anza'' also classifies as a

Mars-crosser A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for i ...

. 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 official discovery observation.

Close approaches

The asteroid has an Earth

minimum orbit intersection distance Minimum orbit intersection distance (MOID) is a measure used in astronomy to assess potential close approaches and collision risks between astronomical objects. It is defined as the distance between the closest points of the osculating orbits o ...

(MOID) of which correspond to 22.2 lunar distances. On 7 October 1960, it passed Earth at and was tracked for a period of 3.5 months to determine a better orbit. It was not observed again until its next near-Earth approach of 1977.

Physical characteristics

In the

Tholen classification An asteroid spectral type is assigned to asteroids based on their reflectance spectrum, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition. For small bodies that are not internally different ...

, ''Anza'' has a rare TCG:

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 ...

Lightcurves

In the 1960s, a 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 ''Anza'' was obtained from photometric observations taken at the discovering observatory by Austrian astronomer Karl Rakos from Graz University Observatory (). Lightcurve analysis gave a

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 ...

of 11.50 hours with a brightness amplitude of 0.3

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

(). No additional lightcurves have been obtained since.

Diameter and albedo

According to

Tom Gehrels Anton M.J. "Tom" Gehrels (February 21, 1925 – July 11, 2011) was a Dutch–American astronomer, Professor of Planetary Sciences, and Astronomer at the University of Arizona, Tucson. Biography Youth and education Gehrels was born at Ha ...

publication in his book ''Hazards Due to Comets and Asteroids'', ''Anza'' measures 2.6 kilometers in diameter, while the ''Collaborative Asteroid Lightcurve Link'' assumes a standard albedo for

carbonaceous Carbonaceous refers to something relating to, containing, or composed of carbon. It is a descriptor used for the attribute of any substance rich in carbon. Particularly, ''carbonaceous hydrocarbons'' are very unsaturated, high- molecular-weight h ...

asteroids of 0.057 and calculates a diameter of 2.71 kilometers based on an absolute magnitude of 16.56.

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

(1736–1788), Spanish explorer and Governor of

Santa Fe de Nuevo México Santa Fe de Nuevo México (; shortened as Nuevo México or Nuevo Méjico, and translated as New Mexico in English) was a province of the Spanish Empire and New Spain, and later a territory of independent Mexico. The first capital was San Juan d ...

for the

Spanish Empire The Spanish Empire, sometimes referred to as the Hispanic Monarchy (political entity), Hispanic Monarchy or the Catholic Monarchy, was a colonial empire that existed between 1492 and 1976. In conjunction with the Portuguese Empire, it ushered ...

in the 18th century, now the U.S state of

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

. He was born in Tucson, Arizona, then

New Spain New Spain, officially the Viceroyalty of New Spain ( ; Nahuatl: ''Yankwik Kaxtillan Birreiyotl''), originally the Kingdom of New Spain, was an integral territorial entity of the Spanish Empire, established by Habsburg Spain. It was one of several ...

, and became the commander at the Spanish fortification

Presidio San Ignacio de Tubac The Presidio of San Ignacio de Túbac or Fort Tubac was a Spanish built fortress. The fortification was established by the Spanish Army in 1752 at the site of present-day Tubac, Arizona. Its ruins are preserved in the Tubac Presid ...

before he explored the first overland route from southern Arizona to California (Monterey). The official 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 1 August 1978 ().

References

{{DEFAULTSORT:Anza 002061 Discoveries by Henry L. Giclas 002061 Named minor planets 002061 19601022