6882 Sormano
Minorplanetyes
Background
  1. D6D6D6
Discovered5 February 1995
DiscovererP. Sicoli
V. Giuliani
Discovery siteSormano Obs.
Mpc name(6882) Sormano
Alt names·
1989 OW · 1993 OQ
Named afterSormano Observatory
(discovering observatory)[1]
Mp category
Epoch4 September 2017 (JD 2458000.5)
Uncertainty0
Observation arc27.85 yr (10,173 days)
Aphelion2.8043 AU
Perihelion2.2997 AU
Semimajor2.5520 AU
Eccentricity0.0989
Period4.08 yr (1,489 days)
Mean anomaly327.31°
Mean motion/ day
Inclination14.390°
Asc node284.19°
Arg peri16.030°
Mean diameter6.69 km (calculated)[4]
7.665 ± 0.101 km[5]
8.096 ± 0.040 km[6]
Rotation3.6901 ± 0.0006 h[7]
3.998344 ± 0.000001 h[8]
Albedo0.21 (assumed)[4]
0.269 ± 0.034[6]
0.3003 ± 0.0545[5]
Abs magnitude12.5[5] · 12.7[3] · 12.736 ± 0.003 (R)[7] · 13.19[4]

6882 Sormano (prov. designation: ) is an stony Eunomia asteroid from the middle region of the asteroid belt, approximately 7 kilometers (4.3 miles) in diameter. It was discovered on 5 February 1995, by Italian amateur astronomers Piero Sicoli and Valter Giuliani at Sormano Astronomical Observatory in northern Italy.[2] The asteroid was named for the Italian mountain-village of Sormano and its discovering observatory.[1]

Orbit and classification

Sormano is a member of the Eunomia family, a large group of S-type asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun at a distance of 2.3–2.8 AU once every 4 years and 1 month (1,489 days). Its orbit has an eccentricity of 0.10 and an inclination of 14° with respect to the ecliptic.[3] The asteroid's observation arc begins 6 years prior to its discovery, as it had previously been observed as at Palomar Observatory in 1989.[2]

Naming

This minor planet was named in honor of the Italian mountain-village of Sormano and its discovering nearby observatory. It is funded, built and operated by the "Gruppo Astrofili Brianza", a group of Italian amateur astronomers who have discovered numerous minor planets.[1] The was published by the Minor Planet Center on 3 May 1996 (M.P.C. 27130).[9]

Physical characteristics

Rotation and shape

In September 2010, a rotational lightcurve of Sormano was obtained from photometric observations made at the Palomar Transient Factory in California. It gave a rotation period of 3.6901 hours with a high brightness variation of 0.71 magnitude, indicative of a non-spheroidal shape (U=2).[7] A similar period of 3.998 hours was derived from remodeled data of the Lowell photometric database (n.a.).[8]

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sormano measures 7.6 to 8.0 kilometers in diameter and its surface has an albedo between 0.269 and 0.300.[5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 6.69 kilometers with an absolute magnitude of 13.19.[4]

References

  1. ^ Schmadel, Lutz D. (2007). "(6882) Sormano". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 563. doi:10.1007/978-3-540-29925-7_6162. ISBN 978-3-540-00238-3.
  2. ^ "6882 Sormano (1995 CC1)". Minor Planet Center. Retrieved 4 November 2016.
  3. ^ "JPL Small-Body Database Browser: 6882 Sormano (1995 CC1)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2017.
  4. ^ No. 6882. Retrieved 4 November 2016.
  5. ^ Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D. et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. S2CID 118700974
  6. ^ Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R. et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. S2CID 119293330. Retrieved 4 November 2016.
  7. ^ 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. S2CID 8342929. Retrieved 4 November 2016.
  8. ^ Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. S2CID 118427201. Retrieved 4 November 2016.
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 November 2016.