astro.wikisort.org - Asteroid

(11474) 1982 SM₂ is a carbonaceous Baptistina asteroid and potentially slow rotator from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 18 September 1982, by Belgian astronomer Henri Debehogne at ESO' La Silla Observatory in northern Chile.[5]

(11474) 1982 SM₂

Discovery[1]
Discovered by	H. Debehogne
Discovery site	La Silla Obs.
Discovery date	18 September 1982
Designations
MPC designation	(11474) 1982 SM2
Alternative designations	1982 SM2 · 1995 KD
Minor planet category	main-belt · Baptistina[2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	32.59 yr (11,905 days)
Aphelion	2.7224 AU
Perihelion	1.8294 AU
Semi-major axis	2.2759 AU
Eccentricity	0.1962
Orbital period (sidereal)	3.43 yr (1,254 days)
Mean anomaly	76.029°
Mean motion	0° 17m 13.56s / day
Inclination	5.4069°
Longitude of ascending node	348.59°
Argument of perihelion	355.61°
Physical characteristics
Dimensions	5.71 km (calculated)[2]
Synodic rotation period	1917.2214±2716 h[3]
Geometric albedo	0.057 (assumed)[2]
Spectral type	C[2]
Absolute magnitude (H)	14.493±0.001 (R)[3] · 14.7[1] · 14.94[2] · 14.94±0.61[4]

Orbit and classification

The C-type asteroid belongs to the small Baptistina family. It orbits the Sun at a distance of 1.8–2.7 AU once every 3 years and 5 months (1,254 days). Its orbit has an eccentricity of 0.20 and an inclination of 5° with respect to the ecliptic.[1] As no precoveries were taken, and no prior identifications were made, the asteroid's observation arc begins with its official discovery observation.[5]

Physical characteristics

In September 2013, a rotational lightcurve of this asteroid was obtained from photometric observations in the R-band at the Palomar Transient Factory in California. It gave an exceptionally long rotation period of 1917 hours with a brightness amplitude of 0.04 magnitude (U=1).[3] However, the fragmentary light-curve has received a low quality rating by the Collaborative Asteroid Lightcurve Link (CALL) which means that the result could be completely wrong (also see potentially slow rotator).[2][3]

CALL assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 5.71 kilometers, based on an absolute magnitude of 14.49.[2]

Numbering and naming

This minor planet was numbered by the Minor Planet Center on 28 September 1999.[6] As of 2018, it has not been named.[5]

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 (10001)-(15000) – Minor Planet Center
• (11474) 1982 SM2 at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• (11474) 1982 SM2 at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

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