astro.wikisort.org - Asteroid

2594 Acamas /ˈækəməs/ is a mid-sized Jupiter trojan from the Trojan camp, approximately 25 kilometers (16 miles) in diameter. It was discovered on 4 October 1978, by American astronomer Charles Kowal at the Palomar Observatory in California.[1] The dark Jovian asteroid has a longer-than average rotation period of 26 hours and possibly an elongated shape.[7] It was named after the Thracian leader Acamas from Greek mythology.[1]

2594 Acamas

Discovery [1]
Discovered by	C. Kowal
Discovery site	Palomar Obs.
Discovery date	4 October 1978
Designations
MPC designation	(2594) Acamas
Pronunciation	/ˈækəməs/[2]
Named after	Acamas (Greek mythology)[1]
Alternative designations	1978 TB · 1977 RR
Minor planet category	Jupiter trojan [1][3] Trojan [4] · background [5]
Orbital characteristics [3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	64.44 yr (23,537 d)
Aphelion	5.4911 AU
Perihelion	4.6313 AU
Semi-major axis	5.0612 AU
Eccentricity	0.0849
Orbital period (sidereal)	11.39 yr (4,159 d)
Mean anomaly	242.01°
Mean motion	0° 5m 11.76s / day
Inclination	5.5341°
Longitude of ascending node	356.69°
Argument of perihelion	279.28°
Jupiter MOID	0.082 AU
TJupiter	2.9840
Physical characteristics
Mean diameter	25.87±0.59 km[6]
Synodic rotation period	25.954±0.0468 h (R)[7][8]
Geometric albedo	0.060±0.006[6]
Spectral type	C (assumed)[7]
Absolute magnitude (H)	11.6[6] 11.8[1][3] 12.31[7]

Orbit and classification

Acamas is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the trailering Trojan camp at the Gas Giant's L₅ Lagrangian point, 60° behind on its orbit (see Trojans in astronomy). It is also a non-family asteroid of the Jovian background population.[5]

It orbits the Sun at a distance of 4.6–5.5 AU once every 11 years and 5 months (4,159 days; semi-major axis of 5.06 AU). Its orbit has an eccentricity of 0.08 and an inclination of 6° with respect to the ecliptic.[3] The body's observation arc begins with a precovery taken at Palomar in September 1953, or 25 years prior to its official discovery observation.[1]

Physical characteristics

Acamas is an assumed, carbonaceous C-type asteroid, while most larger Jupiter trojans are D-type asteroids.[7]

Rotation period

In September 2013, a rotational lightcurve of Acamas was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 25.954±0.0468 hours with a brightness amplitude of 0.50 magnitude (U=2).[7][8] A high brightness variation typically indicates that the body has an elongated rather than spherical shape.

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Acamas measures 25.87 kilometers in diameter and its surface has an albedo 0.06,[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 19.21 kilometers based on an absolute magnitude of 12.31.[7]

Naming

This minor planet was named by IAU's Minor Planet Names Committee from Greek mythology after the warrior Acamas (son of Eussorus), ally of Troy and leader of the Thracian contingent during the Trojan War. He was killed by Ajax.[1]

The name was suggested by Frederick Pilcher and published by the Minor Planet Center on 6 February 1993 (M.P.C. 21606).[1][9]

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
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• Asteroid 2594 Acamas at the Small Bodies Data Ferret
• 2594 Acamas at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 2594 Acamas at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (2594) Acamas

(2594) Acamas ist ein Asteroid aus der Gruppe der Jupiter-Trojaner. Damit werden Asteroiden bezeichnet, die auf den Lagrange-Punkten auf der Bahn des Jupiter um die Sonne laufen. (2594) Acamas wurde am 4. Oktober 1978 von Charles T. Kowal entdeckt.

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- [en] 2594 Acamas

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[ru] (2594) Акамант

(2594) Акамант (лат. Acamas, др.-греч. Ακάμας) — троянский астероид Юпитера, двигающийся в точке Лагранжа L5, в 60° позади планеты. Астероид был открыт 22 ноября 1979 года американским астрономом Чарльзом Ковалем в Паломарской обсерватории и назван в честь Акаманта, одного из персонажей древнегреческой мифологии[1].

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