3391 Sinon

3391 Sinon

Shape model of Sinon from its lightcurve
Discovery [1]
Discovered by	H. Kosai K. Furukawa
Discovery site	Kiso Station
Discovery date	18 February 1977
Designations
MPC designation	(3391) Sinon
Pronunciation	/ˈsaɪnɒn/[2]
Named after	Sinon (Greek mythology)[1]
Alternative designations	1977 DD3
Minor planet category	Jupiter trojan [1][3] Greek [4] · background [5]
Orbital characteristics [3]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	63.16 yr (23,071 d)
Aphelion	5.7383 AU
Perihelion	4.8691 AU
Semi-major axis	5.3037 AU
Eccentricity	0.0819
Orbital period (sidereal)	12.21 yr (4,461 d)
Mean anomaly	200.54°
Mean motion	0° 4m 50.52s / day
Inclination	14.871°
Longitude of ascending node	341.10°
Argument of perihelion	103.13°
Jupiter MOID	0.2572 AU
TJupiter	2.9260
Physical characteristics
Mean diameter	37.86±6.82 km[6] 48.48 km (calculated)[7]
Synodic rotation period	8.135 h[8][a]
Geometric albedo	0.057 (assumed)[7] 0.093±0.036[6]
Spectral type	C (assumed)[7]
Absolute magnitude (H)	10.3[1][3][6][7]

3391 Sinon /ˈsaɪnɒn/ is a mid-sized Jupiter trojan from the Greek camp, approximately 40 kilometers (25 miles) in diameter. It was discovered on 18 February 1977, by Japanese astronomers Hiroki Kosai and Kiichirō Furukawa at the Kiso Observatory in Japan.^[1] The dark Jovian asteroid has a rotation period of 8.1 hours and likely an elongated shape.^[7] It was named after the hero Sinon from Greek mythology.^[1]

Sinon is a dark Jovian asteroid in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at the Gas Giant's L₄ Lagrangian point, 60° ahead on its orbit (see Trojans in astronomy).^[4] It is also a non-family asteroid of the Jovian background population.^[5] It orbits the Sun at a distance of 4.9–5.7 AU once every 12 years and 3 months (4,461 days; semi-major axis of 5.3 AU). Its orbit has an eccentricity of 0.08 and an inclination of 15° with respect to the ecliptic.^[3] The body's observation arc begins with a precovery at Palomar Observatory in March 1953, almost 24 years prior to its official discovery observation at Kiso.^[1]

Sinon is assumed to be a carbonaceous C-type asteroid.^[7]

In February 2013, a rotational lightcurve of Sinon was obtained from photometric observations by Lawrence Wasserman at Lowell Observatory and by Robert Stephens at the Center for Solar System Studies. Lightcurve analysis gave a well-defined rotation period of 8.135±0.002 hours with a brightness amplitude of 0.72 magnitude, indicative of a non-spherical shape (U=3).^[7][8][a]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Sinon measures 37.86 kilometers in diameter and its surface has an albedo of 0.093,^[6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 48.48 kilometers based on an absolute magnitude of 10.3.^[7]

This minor planet was named from Greek mythology after Sinon, a Greek warrior of the Trojan War.^[1] The official naming citation was published by the Minor Planet Center on 16 December 1986 (M.P.C. 11443).^[9]

• 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 3391 Sinon at the Small Bodies Data Ferret
• 3391 Sinon at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 3391 Sinon at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters