4607 Seilandfarm

4607 Seilandfarm
Discovery [1]
Discovered by K. Endate
K. Watanabe
Discovery site Kitami Observatory
Discovery date 25 November 1987
Designations
MPC designation 4607 Seilandfarm
Named after
 Seilandfarm
(Japanese farm)[2]
1987 WR · 1951 CK1
1975 EO4
main-belt · (inner) [3]
Orbital characteristics [1]
Epoch 27 June 2015 (JD 2457200.5)
Uncertainty parameter 0
Observation arc 28.06 yr (10,250 days)
Aphelion 2.3072 AU
Perihelion 2.2203 AU
2.2637 AU
Eccentricity 0.0191
3.41 yr (1,244 days)
352.59°
Inclination 2.2518°
250.57°
221.43°
Known satellites 1 [lower-alpha 1][4]
Physical characteristics
Dimensions 7.389±0.115 km[5]
6.33±0.27 km[6]
7.13 km (calculated)[3]
3.9683±0.0001 h[lower-alpha 2][4]
3.9681±0.0002 h[lower-alpha 2]
0.2239±0.0142[5]
0.279±0.035[6]
0.20 (assumed)[3]
SMASS = L [1]
L [3]
13.1[1]

    4607 Seilandfarm, provisional designation 1987 WR, is a rare-type binary[lower-alpha 1] asteroid from the inner regions of the asteroid belt, about 7 kilometers in diameter. It was discovered on 25 November 1987, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory on the Japanese island of Hokkaidō.[7]

    The reddish body is classified as a rare L-type asteroid on the SMASS taxonomic scheme. It orbits the Sun at a distance of 2.2–2.3 AU once every 3 years and 5 months (1,244 days). Its orbit shows an eccentricity of 0.02 and an inclination of 2 degrees from the plane of the ecliptic.[1] Light-curve photometry rendered a well-defined rotation period of 3.9683±0.0001 and 3.9681±0.0002 hours with a respective brightness amplitude of 0.15 and 0.17 in magnitude, indicating that the asteroid's shape is nearly spheroidal.[lower-alpha 2][4] According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its NEOWISE mission, the asteroid has an albedo of 0.22 and 0.28, with a corresponding diameter of 7.4 and 6.3 kilometers, respectively.[5][6] Although the Collaborative Asteroid Lightcurve Link (CALL) assumes a somewhat more moderate albedo of 0.20, CALL agrees with the findings of the spaced-based surveys and calculates a diameter of 7.1 kilometers.[3]

    In February 2009, the asteroid was discovered to be a binary system. Its asteroid moon has an orbital period of 31.6 hours. Based on mutual eclipse/occultation events, the satellite is thought to be at least 29% the size of Seilandfarm,[lower-alpha 1] which would translate into a diameter of about 2 kilometers or more.

    The minor planet was named for Seilandfarm, a 50-hectare dairy and cattle farm, located in a hilly terrain, near the Japanese city of Kitami, after which the minor planet 3785 Kitami is named, and where the discovering observatory is also located. The farm was established by Akio Seino in 1942, and is now operated by four members of the Seino family.[2]

    References

    1. 1 2 3 CBET No. 1716, 2009 March 11Central Bureau for Astronomical Telegrams for (4607) Seilandfarm:
      Photometric observations obtained during Jan. 17-Feb. 25 reveal that minor planet (4607) is a binary system with an orbital period of 31.63 +/- 0.02 hr. The primary shows a period of 3.9683 +/- 0.0001 hr, and it has a lightcurve amplitude of 0.15 mag, suggesting a nearly spheroidal shape. Mutual eclipse/occultation events indicate a lower limit on secondary-to- primary mean-diameter ratio of 0.29.Central Bureau for Astronomical Telegrams No. 1716
      Reported by: D. Pray, Carbuncle Observatory, W. Brookfield, MA, U.S.A.; P. Kusnirak and P. Pravec, Ondrejov Observatory; J. Gross, W. Cooney, and D. Terrell, Sonoita Research Observatory, Sonoita, AZ; and R. Durkee, Minneapolis, MN.
    2. 1 2 3 Pravec (2009) web: rotation period 3.9683±0.0001 hours with a brightness amplitude of 0.15 mag, as well as Pravec (2014) web: rotation period 3.9681±0.0002 hours with a brightness amplitude of 0.17 mag. Quality Code for both observations: U=3 (denotes a secure result within the precision given and no ambiguity). Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (4607) Seilandfarm
    1. 1 2 3 4 5 "JPL Small-Body Database Browser: 4607 Seilandfarm (1987 WR)" (2015-12-18 last obs.). Jet Propulsion Laboratory. Retrieved January 2016.
    2. 1 2 Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4607) Seilandfarm. Springer Berlin Heidelberg. p. 396. ISBN 978-3-540-00238-3. Retrieved January 2016.
    3. 1 2 3 4 5 "LCDB Data for (4607) Seilandfarm". Asteroid Lightcurve Database (LCDB). Retrieved January 2016.
    4. 1 2 3 Pray, D.; Brookfield, W.; Kusnirak, P.; Pravec, P.; Gross, J.; Cooney, W.; et al. (March 2009). "(4607) Seilandfarm". Central Bureau Electronic Telegrams (1716). Bibcode:2009CBET.1716....1P. Retrieved January 2016.
    5. 1 2 3 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. Retrieved January 2016.
    6. 1 2 3 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters 759 (1): 5. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved January 2016.
    7. ↑ "4607 Seilandfarm (1987 WR)". Minor Planet Center. Retrieved January 2016.

    External links


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