(11474) 1982 SM2

(11474) 1982 SM2
Discovered byH. Debehogne
Discovery siteLa Silla Obs.
Discovery date18 September 1982
(11474) 1982 SM2
1982 SM2 · 1995 KD
main-belt · Baptistina[2]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc32.59 yr (11,905 days)
Aphelion2.7224 AU
Perihelion1.8294 AU
2.2759 AU
3.43 yr (1,254 days)
0° 17m 13.56s / day
Physical characteristics
Dimensions5.71 km (calculated)[2]
1917.2214±2716 h[3]
0.057 (assumed)[2]
14.493±0.001 (R)[3] · 14.7[1] · 14.94[2] · 14.94±0.61[4]

(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]

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]


  1. ^ a b c d "JPL Small-Body Database Browser: 11474 (1982 SM2)" (2015-04-23 last obs.). Jet Propulsion Laboratory. Retrieved 26 May 2017.
  2. ^ a b c d e f g "LCDB Data for (11474)". Asteroid Lightcurve Database (LCDB). Retrieved 16 December 2016.
  3. ^ a b c d Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 16 December 2016.
  4. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 16 December 2016.
  5. ^ a b c "11474 (1982 SM2)". Minor Planet Center. Retrieved 16 December 2016.
  6. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 24 February 2018.

External links[]