6349 Acapulco, provisional designation , is a dark Adeonian

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 ...

from the middle region of the

asteroid belt The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids ...

, approximately 22 kilometers in diameter. The asteroid was discovered on 8 February 1995, by Japanese astronomer

Masahiro Koishikawa was a Japan, Japanese astronomer. He studied both major and minor planets, and discovered multiple asteroids. Koishikawa was a staff member of the Sendai Astronomical Observatory frin 1972. His research was based out of the Sendai's Ayashi (L ...

at the Ayashi Station () of the Sendai Astronomical Observatory in the Tōhoku region of Japan. It was named for the Mexican city of

Acapulco Acapulco de Juárez (), commonly called Acapulco ( , ; ), is a city and Port of Acapulco, major seaport in the Political divisions of Mexico, state of Guerrero on the Pacific Coast of Mexico, south of Mexico City. Located on a deep, semicirc ...

Orbit and classification

''Acapulco'' is a member of the Adeona family (), a large

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of carbonaceous asteroids. It orbits the Sun in the central main-belt at a distance of 2.3–3.0 AU once every 4 years and 4 months (1,590 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 0.14 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 11 ° 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 ...

. In March 1947, it was first identified as at

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 until 2018. O ...

. 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 42 years prior to its official discovery observation at Ayashi, with a

precovery In astronomy, precovery (short for pre-discovery recovery) is the process of finding the image of a celestial object in images or photographic plates predating its discovery, typically for the purpose of calculating a more accurate orbit. This ha ...

taken at

Palomar Observatory The Palomar Observatory is an astronomical research observatory in the Palomar Mountains of San Diego County, California, United States. It is owned and operated by the California Institute of Technology (Caltech). Research time at the observat ...

in 1953.

Physical characteristics

Lightcurves

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 ''Acapulco'' was obtained from photometric observations made at the

Palomar Transient Factory The Palomar Transient Factory (PTF, obs. code: I41), was an astronomical survey using a wide-field survey camera designed to search for optical transient and variable sources such as variable stars, supernovae, asteroids and comets. The projec ...

in September 2010. 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 hours with a brightness variation of 0.18

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 ...

().

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite

IRAS The Infrared Astronomical Satellite (Dutch language, Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a astronomical survey, survey of the entire night sky at infrared wavelengths. Launched on 25 Janu ...

, the Japanese

Akari AKARI (ASTRO-F) was an infrared astronomy satellite developed by Japan Aerospace Exploration Agency, in cooperation with institutes of Europe and Korea. It was launched on 21 February 2006, at 21:28 UTC (06:28, 22 February JST) by M-V rocket ...

satellite, and NASA's

Wide-field Infrared Survey Explorer Wide-field Infrared Survey Explorer (WISE, List of observatory codes, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy Space observatory, space telescope in the Explorers Program launched in December 2009.. . WISE L ...

with its subsequent

NEOWISE Wide-field Infrared Survey Explorer (WISE, observatory code C51, Explorer 92 and MIDEX-6) was a NASA infrared astronomy space telescope in the Explorers Program launched in December 2009.. . WISE discovered thousands of minor planets and nu ...

mission, ''Acapulco'' measures between 14.66 and 23.02 kilometers in diameter, and its surface has an

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

in the range of 0.037 to 0.10. The ''Collaborative Asteroid Lightcurve Link'' assumes an albedo of 0.10 and calculates a smaller diameter of 12.35 kilometers with an absolute magnitude of 12.66.

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 the Mexican city of

, known for its major seaport, which is considered to be among the most beautiful ones in the world. Since 1973, Acapulco is the

sister city A sister city or a twin town relationship is a form of legal or social agreement between two geographically and politically distinct localities for the purpose of promoting cultural and commercial ties. While there are early examples of inte ...

of the Japanese city of

Sendai is the capital Cities of Japan, city of Miyagi Prefecture and the largest city in the Tōhoku region. , the city had a population of 1,098,335 in 539,698 households, making it the List of cities in Japan, twelfth most populated city in Japan. ...

, where the discovering observatory is located, and after which the minor planet 3133 Sendai is named.

Hasekura Tsunenaga was a kirishitan Japanese samurai and retainer of Date Masamune, the daimyō of Sendai. He was of Japanese imperial descent with ancestral ties to Emperor Kanmu. Other names include Philip Francis Faxicura, Felipe Francisco Faxicura, and Ph ...

(1571–1622) – retainer of

Date Masamune was a Japanese ''daimyō'' during the Azuchi–Momoyama period through the early Edo period. Heir to a long line of powerful feudal lords in the Tōhoku region, he went on to found the modern-day city of Sendai. An outstanding tactician, he w ...

, who founded the city of Sendai – stopped by at Acapulco on his diplomatic mission to Rome. 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. Funct ...

on 2 February 1999 .

References

External links

Asteroid Lightcurve Database (LCDB)
query form

)
Dictionary of Minor Planet Names
Google books

– Observatoire de Genève, Raoul Behrend

– Minor Planet Center * * {{DEFAULTSORT:Acapulco 006349 Discoveries by Masahiro Koishikawa Named minor planets 19950208