astro.wikisort.org - Asteroid

5025 Mecisteus, provisional designation: 1986 TS₆, is a larger Jupiter trojan from the Greek camp, approximately 50 kilometers (31 miles) in diameter. The unusual C/X-type Jovian asteroid is possibly a slow rotator with a rotation period of 250 hours.[7] It was discovered on 5 October 1986 by Slovak astronomer Milan Antal at the Toruń Centre for Astronomy in Piwnice, Poland.[1] In 2021, it was named from Greek mythology after the Greek hero Mecisteus who fought in the Trojan War.[13]

5025 Mecisteus

Hubble Space Telescope image of Mecisteus taken in 2013
Discovery[1]
Discovered by	M. Antal
Discovery site	Toruń–Piwnice
Discovery date	5 October 1986
Designations
MPC designation	(5025) Mecisteus
Named after	Mecisteus (Greek mythology)[1][2]
Alternative designations	1986 TS6 · 1989 BX
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	31.64 yr (11,555 d)
Aphelion	5.5876 AU
Perihelion	4.8117 AU
Semi-major axis	5.1996 AU
Eccentricity	0.0746
Orbital period (sidereal)	11.86 yr (4,331 d)
Mean anomaly	221.74°
Mean motion	0° 4m 59.16s / day
Inclination	11.021°
Longitude of ascending node	347.79°
Argument of perihelion	72.958°
Jupiter MOID	0.1039 AU
TJupiter	2.9580
Physical characteristics
Mean diameter	39.84±3.64 km[6] 57.56 km (derived)[7] 57.83±4.9 km[8]
Synodic rotation period	250±25 h[9]
Geometric albedo	0.0404 (derived)[7] 0.0635±0.012[8] 0.084±0.009[6]
Spectral type	C/X (Pan-STARRS)[7][10] C/X (SDSS-MOC)[11][12] V–I = 0.830±0.042[7]
Absolute magnitude (H)	9.8[8] 10.3[1][3][7][6]

Orbit and classification

Mecisteus is a Jupiter trojan which stays in a 1:1 orbital resonance with Jupiter. It is located in the leading Greek camp at its L₄ Lagrangian point, 60° ahead on its orbit (see Trojans in astronomy).[4]

It orbits the Sun at a distance of 4.8–5.6 AU once every 11 years and 10 months (4,331 days; semi-major axis of 5.2 AU). Its orbit has an eccentricity of 0.07 and an inclination of 11° with respect to the ecliptic.[3] The body's observation arc begins with its official discovery observation at Piwnice in October 1986.[1]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 19 January 1992 (M.P.C. 19489).[13] On 29 November 2021, IAU's Working Group Small Body Nomenclature named it after Mecisteus, from Greek mythology. Mecisteus was an Achaean warrior during the Trojan War who was killed by the Trojan Polydamas.[1][2]

Physical characteristics

Mecisteus is an unusual C-/X-type according to Pan-STARRS survey and the SDSS-based taxonomy,[10][11][12] and has a V–I color index of 0.830.[7]

Rotation period

In November 2009, Stefano Mottola at the Calar Alto Observatory observed Mecisteus in a photometric survey of 80 Jupiter trojans. The obtained lightcurve rendered a very long rotation period of 250±25 hours with a brightness variation of 0.2 in magnitude (U=1).[9] However, the Collaborative Asteroid Lightcurve Link (CALL) considers the result as incorrect. As of 2018, no secure period has been obtained.[7]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite (IRAS) and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Mecisteus measures 39.84 and 57.83 kilometers in diameter with an albedo of 0.084 and 0.064, respectively.[8][6] CALL agrees with the results obtained by IRAS, assumes an even lower albedo of 0.0404, and calculates a similar diameter of 57.56 kilometers.[7]

References

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
• 5025 Mecisteus at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 5025 Mecisteus at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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