astro.wikisort.org - Asteroid

1151 Ithaka, provisional designation 1929 RK, is a carbonaceous asteroid from the inner regions of the asteroid belt, approximately 14 kilometers in diameter. It was discovered by Karl Reinmuth at the Heidelberg-Königstuhl State Observatory in 1929, and later named for the Greek island of Ithaca.[11]

1151 Ithaka

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	8 September 1929
Designations
MPC designation	(1151) Ithaka
Named after	Ithaca (Greek Ionian Island)[2]
Alternative designations	1929 RK · 1966 LA
Minor planet category	main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	87.63 yr (32,007 days)
Aphelion	3.0719 AU
Perihelion	1.7417 AU
Semi-major axis	2.4068 AU
Eccentricity	0.2763
Orbital period (sidereal)	3.73 yr (1,364 days)
Mean anomaly	212.71°
Mean motion	0° 15m 50.4s / day
Inclination	6.5616°
Longitude of ascending node	225.42°
Argument of perihelion	122.36°
Earth MOID	0.7459 AU · 290.6 LD
Physical characteristics
Dimensions	8.97±2.41 km[4] 12.120±0.100 km[5][6] 14±3 km[7] 14.37 km (derived)[3] 20.46±4.51 km[8]
Synodic rotation period	4.93115±0.00011 h[7] 4.9314±0.0003 h[lower-alpha 1] 4.932±0.001 h[9]
Geometric albedo	0.02±0.02[8] 0.057 (assumed)[3] 0.069±0.003[5] 0.0692±0.0033[6] 0.13±0.10[4]
Spectral type	C[3]
Absolute magnitude (H)	12.90±0.56[10] · 12.94[3] · 12.94±0.03[7] · 13.10[4][6] · 13.12[8] · 13.2[1]

Discovery

Ithaka was discovered on 8 September 1929, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[11] Five nights later, it was independently discovered by Soviet astronomer Grigory Neujmin at Simeiz Observatory on the Crimean peninsula.[2] Only the first discoverer is acknowledged by the Minor Planet Center.[11] The body's observation arc begins with its official discovery observation at Heidelberg.[11]

Orbit and classification

Ithaka is a non-family asteroid from the background population. It orbits the Sun in the inner main-belt at a distance of 1.7–3.1 AU once every 3 years and 9 months (1,364 days). Its orbit has an eccentricity of 0.28 and an inclination of 7° with respect to the ecliptic.[1]

Physical characteristics

Ithaka is an assumed carbonaceous C-type asteroid,[3] untypical for inner-belt asteroids.

Rotation period

In 2011, three rotational lightcurves of Ithaka were obtained from photometric observations. Lightcurve analysis gave a well-defined rotation period between 4.93115 and 4.932 hours with a brightness amplitude of 0.12 to 0.15 magnitude (U=3/3/3).[7][9][lower-alpha 1]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Ithaka measures between 8.97 and 20.46 kilometers in diameter and its surface has an albedo between 0.02 and 0.13.[4][5][6][8] A collaboration of Italian and American photometrists estimate a diameter of 14±3 kilometers,[7] and the Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and derives a diameter of 14.37 kilometers based on an absolute magnitude of 12.94.[3]

Naming

This minor planet was named after the Greek Ionian Island of Ithaca located in the Ionian Sea. In Greek mythology, the legendary hero Odysseus was the King of Ithaca (also see 1143 Odysseus). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 107).[2]

Notes

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
• 1151 Ithaka at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1151 Ithaka at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (1151) Ithaka

(1151) Ithaka ist ein Asteroid des Hauptgürtels, der am 8. September 1929 vom deutschen Astronomen Karl Wilhelm Reinmuth in Heidelberg entdeckt wurde.

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- [en] 1151 Ithaka

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[fr] (1151) Ithaka

(1151) Ithaka est un astéroïde de la ceinture principale découvert le 8 septembre 1929 par l'astronome allemand Karl Wilhelm Reinmuth. Sa désignation provisoire était 1929 RK.

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