astro.wikisort.org - Asteroid

1138 Attica, provisional designation 1929 WF, is an asteroid from the outer region of the asteroid belt, approximately 24 kilometers in diameter. It was discovered on 22 November 1929, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.[7] It was named after the Attica Province in Greece.[3]

1138 Attica

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	22 November 1929
Designations
MPC designation	(1138) Attica
Pronunciation	/ˈætɪkə/[2]
Named after	Attica Province (province of Greece)[3]
Alternative designations	1929 WF · 1954 GK
Minor planet category	main-belt · (outer)
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc	86.52 yr (31,600 days)
Aphelion	3.3801 AU
Perihelion	2.9104 AU
Semi-major axis	3.1453 AU
Eccentricity	0.0747
Orbital period (sidereal)	5.58 yr (2,037 days)
Mean anomaly	249.74°
Mean motion	0° 10m 36.12s / day
Inclination	13.971°
Longitude of ascending node	283.50°
Argument of perihelion	107.03°
Physical characteristics
Dimensions	23.681±0.113 km[4] 30±2 km (generic)[5]
Synodic rotation period	unknown[6]
Geometric albedo	0.105±0.018[4]
Absolute magnitude (H)	11.4[1]

Orbit and classification

Attica orbits the Sun in the outer main-belt at a distance of 2.9–3.4 AU once every 5 years and 7 months (2,037 days). Its orbit has an eccentricity of 0.07 and an inclination of 14° with respect to the ecliptic.[1] The body's observation arc begins at Heidelberg with its official discovery observation. No precoveries were taken, and no prior identifications were made.[7]

Physical characteristics

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Attica measures 23.681 kilometers in diameter and its surface has an albedo of 0.105.[4] Based on a generic magnitude-to-diameter conversion, its diameter is between 13 and 32 kilometer for an absolute magnitude of 11.4 and an assumed albedo in the range of 0.05 to 0.25.[5] Since asteroids in the outer main-belt are typically of carbonaceous rather than stony composition, with averaged standard albedos of 0.057, Attica's diameter can be estimated to measure close to 30 kilometers, as the lower a body's albedo (reflectivity), the larger its diameter at a fixed absolute magnitude (brightness).[5]

As of 2017, Attica's spectral type, as well as its rotation period and shape remain unknown.[1][6] This is rather unusual, as both spectral type and rotation period have been determined for most larger and low-numbered asteroids (also see minor-planet lists from 1 up to 2000).

Naming

This minor planet is named after the province of Attica in eastern Greece with the capital Athens.[3] Naming citation was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 102).[3]

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• 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
• 1138 Attica at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1138 Attica at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (1138) Attica

(1138) Attica ist ein Asteroid des Hauptgürtels, der am 22. November 1929 vom deutschen Astronomen Karl Wilhelm Reinmuth in Heidelberg entdeckt wurde.

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- [en] 1138 Attica

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[ru] (1138) Аттика

(1138) Аттика (нем. Attica) — астероид из группы главного пояса. Он был открыт 22 ноября 1929 года в обсерватории Гейдельбергского университета немецким астрономом Карлом Рейнмутом. Назван в честь исторической области в Средней Греции, Аттики.

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