|Discovered by||H. L. Giclas|
|Discovery site||Flagstaff (LO)|
|Discovery date||22 October 1960|
|MPC designation||(2061) Anza|
|Juan Bautista de Anza
(Governor of Nuevo México)
|Amor · NEO 
|Orbital characteristics |
|Epoch 4 September 2017 (JD 2458000.5)|
|Uncertainty parameter 0|
|Observation arc||56.56 yr (20,659 days)|
|3.41 yr (1,247 days)|
|0° 17m 19.32s / day|
|Earth MOID||0.0570 AU · 22.2 LD|
2.71 km (calculated)
|Tholen = TCG: 
B–V = 0.825
U–B = 0.350
2061 Anza, provisional designation 1960 UA, is an eccentric asteroid of the Amor group, a subtype of near-Earth objects, 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.
Classification and orbit
Anza is an Amor asteroid – 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 of 0.54 and an inclination of 4° with respect to the ecliptic. Due to its high eccentricity, Anza also classifies as a Mars-crosser. The body's observation arc begins with its official discovery observation.
The asteroid has an Earth minimum orbit intersection distance (MOID) of 0.0570 AU (8,530,000 km) which correspond to 22.2 lunar distances. On 7 October 1960, it passed Earth at 0.0634 AU (9,480,000 km) 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.
In the 1960s, a rotational lightcurve of Anza was obtained from photometric observations taken at the discovering observatory by Austrian astronomer Karl Rakos from Graz University Observatory (580). Lightcurve analysis gave a rotation period of 11.50 hours with a brightness amplitude of 0.3 magnitude (U=2). No additional lightcurves have been obtained since.
Diameter and albedo
According to Tom Gehrels 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 asteroids of 0.057 and calculates a diameter of 2.71 kilometers based on an absolute magnitude of 16.56.
This minor planet was named after Juan Bautista de Anza (1736–1788), Spanish explorer and Governor of Santa Fe de Nuevo México for the Spanish Empire in the 18th century, now the U.S state of New Mexico. He was born in Tucson, Arizona, then New Spain, and became the commander at the Spanish fortification Presidio San Ignacio de Tubac before he explored the first overland route from southern Arizona to California (Monterey).
- "JPL Small-Body Database Browser: 2061 Anza (1960 UA)" (2017-05-15 last obs.). Jet Propulsion Laboratory. Retrieved 3 August 2017.
- Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (2061) Anza. Springer Berlin Heidelberg. p. 167. ISBN 978-3-540-00238-3. Retrieved 3 August 2017.
- Tom Gehrels; Mildred Shapley Matthews; A. M. Schumann (1994). Hazards Due to Comets and Asteroids. University of Arizona Press. pp. 540–543. ISBN 978-0-8165-1505-9.
- "LCDB Data for (2061) Anza". Asteroid Lightcurve Database (LCDB). Retrieved 3 August 2017.
- Rakos, Karl D. (December 1959). "Light variations of the fast moving minor planet : discovered on October 22, 1960, by H.L. Giclas". Bulletin / Lowell Observatory ; no. 109: 28–29:ill.;31cm. Bibcode:1960LowOB...5...28R. Retrieved 3 August 2017.
- "2061 Anza (1960 UA)". Minor Planet Center. Retrieved 3 August 2017.
- "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 3 August 2017.
- Hazards due to Comets and Asteroids (1994)
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 2061 Anza at the JPL Small-Body Database