7846 Setvák

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7846 Setvák
Discovery [1]
Discovered byM. Tichý
Discovery siteKleť Obs.
Discovery date16 January 1996
(7846) Setvák
Named after
Stáňa and Martin Setvák
(Czech meteorologist)[2]
1996 BJ · 1979 OZ2
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc37.53 yr (13,707 days)
Aphelion2.7686 AU
Perihelion1.9306 AU
2.3496 AU
3.60 yr (1,315 days)
Physical characteristics
Dimensions2.69 km (calculated)[3]
2.964±0.127 km[4][5]
2.613±0.0006 h[6]
2.620±0.010 h[7]
0.24 (assumed)[3]
S[3] · LS [8]
14.4[4] · 14.490±0.050 (R)[7] · 14.565±0.001 (R)[6] · 14.6[1] · 14.97±0.27[8] · 15.01[3]

7846 Setvák, provisional designation 1996 BJ, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 3 kilometers in diameter. It was discovered on 16 January 1996, by Czech astronomer Miloš Tichý at Kleť Observatory in South Bohemia.[9] The asteroid was named for Czech couple Stáňa and Martin Setvák.[2]

Orbit and classification[edit]

Setvák is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.9–2.8 AU once every 3 years and 7 months (1,315 days). Its orbit has an eccentricity of 0.18 and an inclination of 3° with respect to the ecliptic.[1] Its observation arc dates back to 1979, due to precoveries obtained at the U.S. Palomar Observatory and the Siding Spring Observatory in Australia.[9]

Physical characteristics[edit]

Diameter and albedo[edit]

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, the asteroid measures 3.0 kilometers in diameter and its surface has a high albedo of 0.35,[4][5] while the Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 (in accordance with the family's largest member and namesake, 8 Flora) and calculates a diameter of 2.7 kilometers.[3] A large-scale survey by Pan-STARRS (PS1) assigns an LS-type, presumably an intermediary spectral type between the common stony S-types and the rather rare and reddish L-type asteroids.[8]

Rotation period[edit]

Two rotational lightcurves were obtained from photometric observations taken in the R-band at the U.S. Palomar Transient Factory in January 2014. The lightcurves gave a rotation period of 2.613 and 2.610 hours with a brightness amplitude of 0.11 and 0.14 in magnitude, respectively (U=2/2).[6][7]


This minor planet was named for Czech meteorologist Martin Setvák (born 1958), amateur astrophotographer and head of the Satellite Department of the Czech Hydrometeorological Institute, to honor his 40th birthday, as well as for his wife Stáňa Setváková (born 1967), a staff member of the Prague Planetarium.[2] The official naming citation was published by the Minor Planet Center on 11 February 1998 (M.P.C. 31298).[10]


  1. ^ a b c d "JPL Small-Body Database Browser: 7846 Setvak (1996 BJ)" (2017-02-01 last obs.). Jet Propulsion Laboratory. Retrieved 22 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(7846) Setvák". Dictionary of Minor Planet Names – (7846) Setvák. Springer Berlin Heidelberg. p. 618. doi:10.1007/978-3-540-29925-7_6702. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f "LCDB Data for (7846) Setvák". Asteroid Lightcurve Database (LCDB). Retrieved 11 March 2017.
  4. ^ a b c d 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.
  5. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 11 March 2017.
  6. ^ a b c 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 11 March 2017.
  7. ^ a b c Chang, Chan-Kao; Ip, Wing-Huen; Lin, Hsing-Wen; Cheng, Yu-Chi; Ngeow, Chow-Choong; Yang, Ting-Chang; et al. (August 2015). "Asteroid Spin-rate Study Using the Intermediate Palomar Transient Factory". The Astrophysical Journal Supplement Series. 219 (2): 19. arXiv:1506.08493. Bibcode:2015ApJS..219...27C. doi:10.1088/0067-0049/219/2/27. Retrieved 11 March 2017.
  8. ^ a b c 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 11 March 2017.
  9. ^ a b "7846 Setvak (1996 BJ)". Minor Planet Center. Retrieved 11 March 2017.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 11 March 2017.

External links[edit]