3581 Alvarez, provisional 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. ...

and a very large Mars-crosser on an eccentric orbit from the asteroid belt, approximately in diameter. It was discovered on 23 April 1985, by American astronomer couple

Carolyn Carolyn is a female given name, a variant of Caroline. Other spellings include Karolyn, Carolyne, Carolynn or Carolynne. Caroline itself is one of the feminine forms of Charles. List of Notable People *Carolyn Bennett (born 1950), Canadian pol ...

and Eugene Shoemaker at the

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 California. The likely spherical

B-type asteroid B-type asteroids are a relatively uncommon type of carbonaceous asteroid, falling into the wider C-group; the 'B' indicates these objects are spectrally blue. In the asteroid population, B-class objects can be found in the outer asteroid belt, an ...

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 33.4 hours. It was named for scientists Luis Alvarez and his son Walter Alvarez.

Orbit and classification

''Alvarez'' is a Mars-crossing asteroid, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.66 AU. However, due to the high inclination of its orbit, it never actually passes through the orbit of Mars since at perihelion it is well away from Mars' orbital plane. It orbits the Sun at a distance of 1.7–3.9 AU once every 4 years and 7 months (1,689 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 2.78 AU). Its orbit has an eccentricity of 0.41 and an inclination of 29 ° with respect to the ecliptic. The body's observation arc begins with its first observation as ' at

Goethe Link Observatory The Goethe Link Observatory, observatory code 760, is an astronomical observatory near Brooklyn, Indiana, United States. It is owned by Indiana University and operated by the Indiana Astronomical Society https://iasindy.org/about.html, which eff ...

in May 1962, almost 23 years prior to its official discovery observation at Palomar.

Naming

This minor planet was named after planetary scientist Walter Alvarez (born 1940) and his Nobel-prize winning father, physicist Luis Walter Alvarez (1911–1988). Both at University of California, Berkeley, they are best known for the discovery of a global geochemical anomaly of noble metals at the K-T boundary, which led to hypothesis that the dinosaurs were killed by an asteroid impact ''(also see Alvarez hypothesis)''. 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. Function ...

on 2 February 1988 (), just a few months after the naming was announcement on the occasion of the second ''Conference on Global Catastrophes in Earth History'', held in October 1987 at Snowbird, Utah.

Physical characteristics

In the

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

, ''Alvarez'' is a carbonaceous

, somewhat "brighter" than the more common C-type asteroids.

Rotation period

In September 2004, a rotational lightcurve of ''Alvarez'' was obtained from photometric observations by American photometrist William Koff at the Antelope Hills Observatory in Bennett, Colorado. Lightcurve analysis gave a longer-than-average

of hours with a small brightness amplitude of magnitude (), indicative of a spherical rather than elongated shape. The result supersedes a previous period determination by

Wiesław Wiśniewski :"Wiesław" is sometimes transliterated as "Wieslaw", in the absence of ''L with stroke.'' Wiesław () is a Polish masculine given name, of Slavonic origin, meaning "great glory" or "all glory". It is the shortened, more common, form of the person ...

from 1990, which gave a period of at least 24 hours ().

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, ''Alvarez'' measures 13.69 kilometers in diameter and its surface has an albedo of 0.113. Previously published WISE data from 2013 and 2016 gave a concurring diameter of 14 and 13.7 kilometer with an albedo of 0.14 and 0.13, respectively. The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.057 and derives a diameter of 18.43 kilometers based on an absolute magnitude of 12.4. With a diameter close to 14 kilometers, ''Alvarez'' is larger than most sizeable Mars-crossing asteroids such as 1065 Amundsenia (9.75 km), 1139 Atami (9.35 km), 1011 Laodamia (7.39 km), 1727 Mette (5.44 km), 1131 Porzia (7.13 km),

1235 Schorria 1235 Schorria ('' prov. designation:'' ), is a Hungaria asteroid, sizable Mars-crosser, and exceptionally slow rotator from the inner region of the asteroid belt. The carbonaceous C-type asteroid has an outstandingly long rotation period of ...

(5.55 km), 985 Rosina (8.18 km) and 1468 Zomba (7 km), comparable with 1310 Villigera (15.24 km) and 1474 Beira (15.46 km), but still smaller than the largest members of this dynamical group, namely,

132 Aethra Aethra (minor planet designation: 132 Aethra) is a metallic asteroid and Mars-crosser on an eccentric orbit from the asteroid belt. It measures approximately 40 kilometers in diameter. It was discovered by James Craig Watson in 1873 and is the ...

, 323 Brucia (former Mars-crosser), 1508 Kemi, 2204 Lyyli and 512 Taurinensis, which are larger than 20 kilometers in diameter in at least one of the publications.

Notes

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Minor Planet Center * * {{DEFAULTSORT:Alvarez 003581 Discoveries by Eugene Merle Shoemaker Discoveries by Carolyn S. Shoemaker Named minor planets 003581 19850423